Which of the Following Elements Can Be Prepared by Electrolysis of Their Aqueous Salts:
Trouble 1
Define oxidation and reduction in terms of electron transfer
and change in oxidation number.
Ahmed A.
Numerade Educator
Problem 2
Why must an electrochemical procedure involve a redox reaction?
Ahmed A.
Numerade Educator
Problem iii
Tin can 1 half-reaction in a redox process take place independently of the other? Explain.
Ahmed A.
Numerade Educator
Trouble 4
H2o is used to residuum O atoms in the half-reaction method. Why can't $\mathrm{O}^{2-}$ ions be used instead?
Ahmed A.
Numerade Educator
Trouble 5
During the redox balancing process, what stride is taken to ensure that $\mathrm{e}^{-}$ loss equals $\mathrm{east}^{-}$ gain?
Ahmed A.
Numerade Educator
Problem 6
How are protons removed when balancing a redox reaction in basic solution?
Ahmed A.
Numerade Educator
Problem 7
Are spectator ions used to remainder the one-half-reactions of a redox reaction? At what stage might spectator ions enter the balancing process?
Ahmed A.
Numerade Educator
Problem eight
Which type of electrochemical jail cell has $\Delta G_{\text { sys }}<0 ?$ Which blazon shows an increment in free free energy?
Ahmed A.
Numerade Educator
Problem 9
Which statements are true? Correct any that are false.
(a) In a voltaic jail cell, the anode is negative relative to the cathode.
(b) Oxidation occurs at the anode of a voltaic or electrolytic prison cell.
(c) Electrons flow into the cathode of an electrolytic jail cell.
(d) In a voltaic cell, the surroundings do work on the organisation.
(e) A metal that plates out of an electrolytic cell appears on the
cathode.
(f) In an electrochemical cell, the electrolyte provides a solution
of mobile electrons.
Ahmed A.
Numerade Educator
Problem ten
Consider the following balanced redox reaction:
$\begin{aligned} sixteen \mathrm{H}^{+}(a q)+2 \mathrm{MnO}_{4}^{-}(a q)+& x \mathrm{Cl}^{-}(a q) \longrightarrow \\ & two \mathrm{Mn}^{2+}(a q)+5 \mathrm{Cl}_{2}(thousand)+8 \mathrm{H}_{ii} \mathrm{O}(50) \cease{aligned}$
(a) Which species is being oxidized?
(b) Which species is being reduced?
(c) Which species is the oxidizing agent?
(d) Which species is the reducing agent?
(due east) From which species to which does electron transfer occur?
(f) Write the balanced molecular equation, with $\mathrm{K}^{+}$ and $\mathrm{Then}_{4}^{two-}$
the spectator ions.
Ahmed A.
Numerade Educator
Problem 11
Consider the post-obit counterbalanced redox reaction
$$
\begin{aligned} 2 \mathrm{CrO}_{2}^{-}(a q)+2 \mathrm{H}_{two} \mathrm{O}(l)+& 6 \mathrm{ClO}^{-}(a q) \longrightarrow \\ & 2 \mathrm{CrO}_{iv}^{2-}(a q)+3 \mathrm{Cl}_{2}(g)+iv \mathrm{OH}^{-}(a q) \terminate{aligned}
$$
(a) Which species is being oxidized?
(b) Which species is existence reduced?
(c) Which species is the oxidizing agent?
(d) Which species is the reducing agent?
(e) From which species to which does electron transfer occur?
(f) Write the balanced molecular equation, with Na' $^{2}$ the
spectator ion.
Ahmed A.
Numerade Educator
Problem 12
Residual the following skeleton reactions and identify the oxidizing and reducing agents:
(a) $\mathrm{O}_{2}(g)+\mathrm{NO}(grand) \longrightarrow \mathrm{NO}_{three}^{-(a q)}[\text { acidic }]$
(b) $\mathrm{CrO}_{iv}^{ii-}(a q)+\mathrm{Cu}(due south) \longrightarrow \mathrm{Cr}(\mathrm{OH})_{3}(south)+\mathrm{Cu}(\mathrm{OH})_{two}(southward)[\text { basic }]$
(c) $\mathrm{AsO}_{iv}^{3-}(a q)+\mathrm{NO}_{2}^{-}(a q) \longrightarrow$ $\mathrm{AsO}_{2}^{-}(a q)+\mathrm{NO}_{iii}^{-}(a q)[\mathrm{bones}]$
Kristen J.
Numerade Educator
Problem 12
The overall prison cell reaction occurring in an alkaline bombardment is
$$\mathrm{Zn}(s)+\mathrm{MnO}_{ii}(s)+\mathrm{H}_{2} \mathrm{O}(50) \longrightarrow \mathrm{ZnO}(s)+\mathrm{Mn}(\mathrm{OH})_{ii}(south)$$
(a) How many moles of electrons flow per mole of reaction?
(b) If 4.l $\mathrm{g}$ of zinc is oxidized, how many grams of manganese dioxide and of water are consumed?
(c) What is the total mass of reactants consumed in office (b)?
(d) How many coulombs are produced in part (b)?
(eastward) In practice, voltaic cells of a given capacity (coulombs) are heavier than the calculation in part(c) indicates. Explain.
Sourav One thousand.
Numerade Educator
Problem thirteen
Balance the following skeleton reactions and identify the oxidizing and reducing agents:
(a) $\mathrm{O}_{2}(m)+\mathrm{NO}(m) \longrightarrow \mathrm{NO}_{3}^{-}(a q)[\text { acidic }]$(b) $\mathrm{CrO}_{iv}^{2-}(a q)+\mathrm{Cu}(s) \longrightarrow \mathrm{Cr}(\mathrm{OH})_{3}(b)+\mathrm{Cu}(\mathrm{OH})_{2}(due south)[\text { basic }]$
(c) $\mathrm{AsO}_{iv}^{three-}(a q)+\mathrm{NO}_{2}^{-(a q)} \longrightarrow_{\mathrm{AsO}_{two}^{-}(a q)+\mathrm{NO}_{3}^{-}(a q)[\text { basic }]}$
Kristen J.
Numerade Educator
Problem 14
Balance the post-obit skeleton reactions and identify the oxidizing and reducing agents:
(a) $\mathrm{Cr}_{2} \mathrm{O}_{seven}^{2-}(a q)+\mathrm{Zn}(s) \longrightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{Cr}^{3+}(a q)$ [acidic]
(b) $\mathrm{Fe}(\mathrm{OH})_{2}(s)+\mathrm{ MnO}_{four}^{-}(a q) \longrightarrow$ $\mathrm{MnO}_{ii}(southward)+\mathrm{Iron}(\mathrm{OH})_{3}(southward)[\mathrm{basic}]$
(c) $\operatorname{Zn}(s)+\mathrm{NO}_{three}^{-}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+\mathrm{N}_{2}(g)[\text { acidic }]$
Navkiran J.
Numerade Educator
Trouble 15
Balance the following skeleton reactions and identify the oxidizing and reducing agents:
(a) $\mathrm{BH}_{4}^{-}(a q)+\mathrm{ClO}_{3}^{-}(a q) \longrightarrow \mathrm{H}_{2} \mathrm{BO}_{iii}^{-}(a q)+\mathrm{Cl}^{-}(a q)[\mathrm{bones}]$
(b) $\mathrm{CrO}_{iv}^{2-}(a q)+\mathrm{N}_{ii} \mathrm{O}(1000) \longrightarrow \mathrm{Cr}^{iii+}(a q)+\mathrm{NO}(g)[\text { acidic }]$
(c) $\mathrm{Br}_{ii}(l) \longrightarrow \mathrm{BrO}_{three}^{-}(a q)+\mathrm{Br}^{-}(a q)[\text { bones }]$
Navkiran J.
Numerade Educator
Problem xvi
Balance the following skeleton reactions and place the oxidizing and reducing agents:
(a) $\mathrm{Sb}(s)+\mathrm{NO}_{3}^{-}(a q) \longrightarrow \mathrm{Sb}_{4} \mathrm{O}_{half-dozen}(s)+\mathrm{NO}(yard)[\text { acidic }]$
(b) $\operatorname{Mn}^{2+}(a q)+\operatorname{Bi} \mathrm{O}_{3}^{-}(a q) \longrightarrow$ $\mathrm{MnO}_{iv}^{-}(a q)+\mathrm{Bi}^{3+}(a q)[\text { acidic }]$
(c) $\mathrm{Fe}(\mathrm{OH})_{2}(s)+\mathrm{Pb}(\mathrm{OH})_{three}^{-}(a q) \longrightarrow$ $\mathrm{Fe}(\mathrm{OH})_{3}(south)+\mathrm{Pb}(s)[\text { basic }]$
Navkiran J.
Numerade Educator
Problem 17
Residue the post-obit skeleton reactions and identify the oxidizing and reducing agents:
(a) $\mathrm{NO}_{two}(chiliad) \longrightarrow \mathrm{NO}_{three}^{-}(a q)+\mathrm{NO}_{2}^{-}(a q)[\text { basic }]$
(b) $\mathrm{Zn}(s)+\mathrm{NO}_{3}^{-}(a q) \longrightarrow \mathrm{Zn}(\mathrm{OH})_{4}^{2-}(a q)+\mathrm{NH}_{3}(g)[\text { basic }]$
(c) $\mathrm{H}_{2} \mathrm{S}(chiliad)+\mathrm{NO}_{three}^{-}(a q) \longrightarrow \mathrm{South}_{8}(s)+\mathrm{NO}(g)[\text { acidic }]$
Navkiran J.
Numerade Educator
Problem xviii
Balance the post-obit skeleton reactions and identify the oxidizing and reducing agents:
(a) $\mathrm{As}_{iv} \mathrm{O}_{6}(south)+\mathrm{MnO}_{4}^{-}(a q) \longrightarrow$ $\mathrm{AsO}_{4}^{3-}(a q)+\mathrm{Mn}^{2+}(a q)[\text { acidic }]$
(b) $\mathrm{P}_{4}(s) \longrightarrow \mathrm{HPO}_{3}^{two-}(a q)+\mathrm{PH}_{3}(g)[\text { acidic }]$
(c) $\mathrm{MnO}_{iv}^{-}(a q)+\mathrm{CN}^{-}(a q) \longrightarrow \mathrm{MnO}_{2}(s)+\mathrm{CNO}^{-}(a q)[\text { bones }]$
Navkiran J.
Numerade Educator
Problem nineteen
Remainder the following skeleton reactions and place the oxidizing and reducing agents:
(a) $\mathrm{SO}_{3}^{ii-}(a q)+\mathrm{Cl}_{2}(g) \longrightarrow \mathrm{SO}_{4}^{2-}(a q)+\mathrm{Cl}^{-}(a q)[\text { basic }]$
(b) $\mathrm{Fe}(\mathrm{CN})_{six}^{3-}(a q)+\operatorname{Re}(s) \longrightarrow$ $\mathrm{Iron}(\mathrm{CN})_{6}^{four-}(a q)+\mathrm{ReO}_{4}^{-}(a q)[\mathrm{basic}]$
(c) $\operatorname{Mn} \mathrm{O}_{4}^{-}(a q)+\mathrm{HCOOH}(a q) \longrightarrow$ $\mathrm{Mn}^{2+}(a q)+\mathrm{CO}_{ii}(1000)[\text { acidic }]$
Navkiran J.
Numerade Educator
Problem xx
In many residential h2o systems, the aqueous Iron $^{three+} \mathrm{concentration}$ is high enough to stain sinks and turn drinking water light dark-brown. The iron content is analyzed past first reducing the
$\mathrm{Fe}^{3+}$ to $\mathrm{Iron}^{2+}$ and and so titrating with MnO $_{4}-$ in acidic solution.
Balance the skeleton reaction of the titration step:
$$
\mathrm{Fe}^{2+}(a q)+\mathrm{MnO}_{4}^{-}(a q) \longrightarrow \mathrm{Mn}^{ii+}(a q)+\mathrm{Fe}^{3+}(a q)
$$
Ahmed A.
Numerade Educator
Trouble 21
Aqua regia, a mixture of concentrated $\mathrm{HNO}_{2}$ and $\mathrm{HCl}$ , was developed by alchemists as a means to "dissolve" gold. The process is a redox reaction with this simplified skeleton reaction:
$$
\mathrm{Au}(s)+\mathrm{NO}_{iii}^{-}(a q)+\mathrm{Cl}^{-}(a q) \longrightarrow \mathrm{AuCl}_{four}^{-}(a q)+\mathrm{NO}_{2}(g)
$$
(a) Residuum the reaction by the half-reaction method.
(b) What are the oxidizing and reducing agents?
(c) What is the function of $\mathrm{HCl}$ in aqua regia?
Ahmed A.
Numerade Educator
Problem 22
Consider the following general voltaic cell:
Identify the following:
(a) Anode
(b) Cathode
(c) Salt bridge
(d) Electrode from which e- leave the cell
(due east) Electrode with a positive charge
(f) Electrode that gains mass as the cell operates (assuming that a
metal plates out)
Ahmed A.
Numerade Educator
Problem 23
Why does a voltaic cell not operate unless the ii compartments are connected through an external circuit?
Ahmed A.
Numerade Educator
Problem 24
What purpose does the salt bridge serve in a voltaic cell, and how does it accomplish this purpose?
Ahmed A.
Numerade Educator
Problem 25
What is the difference betwixt an active and an inactive electrode? Why are inactive electrodes used? Name two substances commonly used for inactive electrodes.
Ahmed A.
Numerade Educator
Problem 26
When a piece of metal A is placed in a solution containing
ions of metallic B, metal B plates out on the piece of A.
(a) Which metal is beingness oxidized?
(b) Which metal is being displaced?
(c) Which metal would y'all use as the anode in a voltaic cell
incorporating these two metals?
(d) If bubbles of $\mathrm{H}_{2}$ class when $\mathrm{B}$ is placed in acid, will they form
if $\mathrm{A}$ is placed in acid? Explicate.
Ahmed A.
Numerade Educator
Problem 27
Consider the following voltaic prison cell:
(a) In which management exercise electrons menstruum in the external circuit?
(b) In which one-half-cell does oxidation occur?
(c) In which half-cell exercise electrons enter the cell?
(d) At which electrode are electrons consumed?
(eastward) Which electrode is negatively charged?
(f) Which electrode decreases in mass during jail cell performance?
(g) Propose a solution for the electrolyte in the cathode
compartment.
(h) Suggest a pair of ions for the common salt bridge.
(i) For which electrode could you use an inactive material?
(j) In which direction do anions inside the salt bridge move to
maintain accuse neutrality?
(k) Write counterbalanced half-reactions and the overall cell reaction.
Ahmed A.
Numerade Educator
Problem 28
Consider the following voltaic cell:
(a) In which direction practise electrons catamenia in the external circuit?
(b) In which half-prison cell does reduction occur?
(c) In which half-prison cell do electrons go out the prison cell?
(d) At which electrode are electrons generated?
(due east) Which electrode is positively charged?
(f) Which electrode increases in mass during jail cell operation?
(g) Suggest a solution you lot tin can utilize as the electrolyte in the anode
compartment.
(h) Advise a pair of ions for the salt bridge.
(i) For which electrode could y'all use an inactive material?
(j) In which management exercise cations within the salt span move to
maintain charge neutrality?
(grand) Write balanced half-reactions and the overall cell reaction.
Sourav K.
Numerade Educator
Problem 29
A voltaic cell is constructed with an $\mathrm{Sn} / \mathrm{Sn}^{2+}$ half-cell and a Zn/Zn'+ half-prison cell. The zinc electrode is negative.
(a) Write counterbalanced half-reactions and the overall cell reaction.
(b) Diagram the cell, labeling electrodes with their charges and showing the directions of electron catamenia in the excursion and of cation and anion flow in the salt bridge.
Ahmed A.
Numerade Educator
Problem 30
A voltaic jail cell is constructed with an Ag/Ag $^{+}$ one-half-prison cell and a Pb/Pb ^{2+} half-cell. The argent electrode is positive.
(a) Write balanced half-reactions and the overall cell reaction.
(b) Diagram the cell, labeling electrodes with their charges and showing the directions of electron flow in the circuit and of cation and anion flow in the salt span.
Ahmed A.
Numerade Educator
Problem 31
A voltaic cell is constructed with an Atomic number 26/Fe $^{2+}$ one-half-cell and an $\mathrm{Mn} / \mathrm{Mn}^{2+}$ half-cell. The iron electrode is positive.
(a) Write balanced half-reactions and the overall cell reaction.
(b) Diagram the cell, labeling electrodes with their charges and showing the directions of electron flow in the circuit and of cation and anion flow in the salt bridge.
Ahmed A.
Numerade Educator
Problem 32
A voltaic cell is constructed with a $\mathrm{Cu} / \mathrm{Cu}^{2+}$ half-cell and an $\mathrm{Ni} / \mathrm{Ni}^{2+}$ half-prison cell. The nickel electrode is negative.
(a) Write balanced half-reactions and the overall jail cell reaction.
(b) Diagram the jail cell, labeling electrodes with their charges and
showing the directions of electron menstruation in the circuit and of cation
and anion menstruum in the salt bridge.
Ahmed A.
Numerade Educator
Problem 33
Write the cell notation for the voltaic cell that incorporates
each of the following reactions:
(a) All(s) $+\mathrm{Cr}^{three+}(a q) \longrightarrow \mathrm{Al}^{3+}(a q)+\mathrm{Cr}(due south)$
(b) $\mathrm{Cu}^{2+}(a q)+\mathrm{And so}_{ii}(g)+2 \mathrm{H}_{two} \mathrm{O}(l) \longrightarrow$
$$
\mathrm{Cu}(southward)+\mathrm{SO}_{4}^{2-}(a q)+4 \mathrm{H}^{+}(a q)
$$
Ahmed A.
Numerade Educator
Problem 34
Write a balanced equation from each prison cell annotation:
(a) $\operatorname{Mn}(s)\left|\mathrm{Mn}^{2+}(a q) \| \mathrm{Cd}^{two+}(a q)\right| \mathrm{Cd}(s)$
(b) Fe(s) $\left|\mathrm{Atomic number 26}^{2+}(a q) \| \mathrm{NO}_{three}^{-}(a q)\correct| \mathrm{NO}(grand) | \mathrm{Pt}(southward)$
Ahmed A.
Numerade Educator
Problem 35
How is a standard reference electrode used to determine unknown $E_{\text { half-cell values? }}^{\circ}$ values?
Ahmed A.
Numerade Educator
Problem 36
What does a negative $E_{\text { cell }}^{\circ}$ point about a redox reaction? What does it indicate about the reverse reaction?
Ahmed A.
Numerade Educator
Problem 37
The standard prison cell potential is a thermodynamic state function. How are $East^{\circ}$ values treated similarly to $\Delta H^{\circ}, \Delta G^{\circ},$ and $South^{\circ}$ values? How are they treated differently?
Ahmed A.
Numerade Educator
Problem 38
In bones solution, $\mathrm{Se}^{2-}$ and $\mathrm{And then}_{3}^{2-}$ ions react spontaneously:
$$
\brainstorm{assortment}{50}{ii \mathrm{Se}^{2-}(a q)+2 \mathrm{And then}_{iii}^{2-}(a q)+3 \mathrm{H}_{2} \mathrm{O}(fifty) \longrightarrow} \\ {2 \mathrm{Se}(s)+6 \mathrm{OH}^{-}(a q)+\mathrm{South}_{2} \mathrm{O}_{3}^{2-}(a q) \quad E_{\mathrm{cell}}^{\circ}=0.35 \mathrm{5}}\finish{array}
$$
(a) Write balanced half-reactions for the procedure.
(b) If $E_{\text { sulfite }}^{\circ}$ is $-0.57 \mathrm{V},$ summate $E_{\text { selenium }}^{\circ} .$
Ahmed A.
Numerade Educator
Problem 39
In acidic solution, $\mathrm{O}_{3}$ and $\mathrm{Mn}^{ii+}$ ions react spontaneously:
$$
\begin{array}{c}{\mathrm{O}_{3}(g)+\mathrm{Mn}^{2+}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow} \\ {\qquad \mathrm{O}_{2}(g)+\mathrm{MnO}_{two}(s)+2 \mathrm{H}^{+}(a q)} & {E_{\mathrm{cell}}^{\circ}=0.84 \mathrm{V}}\end{assortment}
$$
(a) Write the counterbalanced half-reactions.
(b) Using Appendix D to find $E_{\text { ozone }}^{\circ}$ calculate $E_{\text { manganese }}^{\circ}$
Navkiran J.
Numerade Educator
Problem xl
Employ the emf serial (Appendix D) to arrange the species.
(a) In social club of decreasing strength equally oxidizing agents: $\mathrm{Fe}^{3+}, \mathrm{Br}_{two}$
$\mathrm{Cu}^{2+}$
(b) In social club of increasing strength every bit oxidizing agents: $\mathrm{Ca}^{two+}$ ,
$\mathrm{Cr}_{two} \mathrm{O}_{7}^{2-}, \mathrm{Ag}^{+}$
Ahmed A.
Numerade Educator
Problem 41
Use the emf series (Appendix D) to adjust the species.
(a) In order of decreasing strength as reducing agents: $\mathrm{SO}_{ii}$
PbSO, $\mathrm{MnO}_{2}$
(b) In order of increasing strength as reducing agents: Hg, Fe, Sn
Prashant B.
Numerade Educator
Problem 42
Balance each skeleton reaction, utilize Appendix D to summate $E_{\text { cell }}^{\circ}$ and country whether the reaction is spontaneous:
(a) $\mathrm{Co}(southward)+\mathrm{H}^{+}(a q) \longrightarrow \mathrm{Co}^{2+}(a q)+\mathrm{H}_{two}(g)$
(b) $\mathrm{Hg}_{2}^{ii+}(a q) \longrightarrow \mathrm{Hg}^{2+}(a q)+\mathrm{Hg}(fifty)$
Ahmed A.
Numerade Educator
Problem 43
Rest each skeleton reaction, use Appendix $D$ to calculate $E_{\text { cll }}^{\circ}$ and state whether the reaction is spontaneous:
(a) $\operatorname{Mn}^{2+}(a q)+\mathrm{Co}^{3+}(a q) \longrightarrow \mathrm{MnO}_{2}(southward)+\mathrm{Co}^{2+}(a q)[\text { acidic }]$
(b) $\mathrm{AgCl}(south)+\mathrm{NO}(g) \longrightarrow$
$\mathrm{Ag}(s)+\mathrm{Cl}^{-}(a q)+\mathrm{NO}_{3}^{-}(a q)[\text { acidic }]$
Navkiran J.
Numerade Educator
Problem 44
Balance each skeleton reaction, use Appendix D to calcu-
belatedly $E_{\text { cell }}^{\circ}$ and country whether the reaction is spontaneous:
(a) $\mathrm{Cd}(south)+\mathrm{Cr}_{2} \mathrm{O}_{seven}^{two-}(a q) \longrightarrow \mathrm{Cd}^{2+}(a q)+\mathrm{Cr}^{iii+}(a q)$
(b) $\mathrm{Ni}^{ii+}(a q)+\mathrm{Lead}(s) \longrightarrow \mathrm{Ni}(southward)+\mathrm{Pb}^{2+}(a q)$
Ahmed A.
Numerade Educator
Problem 45
Residual each skeleton reaction, utilise Appendix D to calculate $E_{\mathrm{cel}}^{\circ}$ and country whether the reaction is spontaneous:
(a) $\mathrm{Cu}^{+}(a q)+\mathrm{PbO}_{two}(due south)+\mathrm{Then}_{four}^{2-}(a q) \longrightarrow$
(b) $\mathrm{H}_{2} \mathrm{O}_{2}(a q)+\mathrm{Ni}^{two+}(a q) \longrightarrow \mathrm{O}_{2}(1000)+\mathrm{Ni}(s)[\text { acidic }]$
Ahmed A.
Numerade Educator
Problem 46
Use the following half-reactions to write three spontaneous reactions, calculate $E_{\text { cell }}^{\circ}$ for each reaction, and rank the strengths of the oxidizing and reducing agents:
(i) $\mathrm{Al}^{3+}(a q)+3 \mathrm{eastward}^{-} \longrightarrow \mathrm{Al}(s) \quad E^{\circ}=-1.66 \mathrm{Five}$
(2) $\mathrm{N}_{2} \mathrm{O}_{four}(k)+2 \mathrm{e}^{-} \longrightarrow 2 \mathrm{NO}_{two}^{-}(a q) \qquad E^{\circ}=0.867 \mathrm{V}$
(iii) $\mathrm{So}_{iv}^{ii-}(a q)+\mathrm{H}_{2} \mathrm{O}(l)+2 \mathrm{e}^{-} \longrightarrow \mathrm{Then}_{3}^{2-}(a q)+2 \mathrm{OH}^{-}(a q)$
$E^{\circ}=0.93 \mathrm{Five}$
Ahmed A.
Numerade Educator
Trouble 47
Utilise the following one-half-reactions to write iii spontaneous reactions, calculate $E_{\mathrm{cell}}^{\circ}$ for each reaction, and rank the strengths of the oxidizing and reducing agents:
(1) $\mathrm{Au}^{+}(a q)+\mathrm{e}^{-} \longrightarrow \mathrm{Au}(due south) \quad E^{\circ}=1.69 \mathrm{V}$
(ii) $\mathrm{N}_{2} \mathrm{O}(g)+ii \mathrm{H}^{+}(a q)+2 \mathrm{e}^{-} \longrightarrow \mathrm{N}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(l)$
$(3) \mathrm{Cr}^{three+}(a q)+3 \mathrm{e}^{-} \longrightarrow \mathrm{Cr}(south) \qquad E^{\circ}=-0.74 \mathrm{V}$
Navkiran J.
Numerade Educator
Problem 48
Employ the post-obit half-reactions to write three spontaneous reactions, calculate $E_{\text { cell }}^{\circ}$ for each reaction, and rank the strengths of the oxidizing and reducing agents:
(one) $2 \mathrm{HClO}(a q)+2 \mathrm{H}^{+}(a q)+2 \mathrm{e}^{-} \longrightarrow \mathrm{Cl}_{ii}(g)+2 \mathrm{H}_{2} \mathrm{O}(l)$
(ii) $\mathrm{Pt}^{ii+}(a q)+two \mathrm{eastward}^{-} \longrightarrow \mathrm{Pt}(s) \quad East^{\circ}=i.20 \mathrm{V}$
(three) $\mathrm{PbSO}_{4}(s)+2 \mathrm{e}^{-} \longrightarrow \mathrm{Pb}(southward)+\mathrm{SO}_{four}^{2-}(a q) \quad E^{\circ}=-0.31 \mathrm{V}$
Ahmed A.
Numerade Educator
Trouble 49
Utilise the post-obit one-half-reactions to write 3 spontaneous reactions, calculate $E_{\mathrm{jail cell}}^{\circ}$ for each reaction, and rank the strengths of the oxidizing and reducing agents:
(i) $\mathrm{I}_{ii}(south)+2 \mathrm{e}^{-} \longrightarrow two \mathrm{I}^{-}(a q) \quad E^{\circ}=0.53 \mathrm{V}$
(two) $\mathrm{Due south}_{2} \mathrm{O}_{eight}^{two-}(a q)+2 \mathrm{e}^{-} \longrightarrow 2 \mathrm{Then}_{4}^{2-}(a q) \qquad Eastward^{\circ}=two.01 \mathrm{V}$
(3) $\mathrm{Cr}_{2} \mathrm{O}_{seven}^{2-}(a q)+xiv \mathrm{H}^{+}(a q)+half-dozen \mathrm{e}^{-} \longrightarrow$
$$
2 \mathrm{Cr}^{3+}(a q)+7 \mathrm{H}_{ii} \mathrm{O}(50) \quad Eastward^{\circ}=1.33 \mathrm{V}
$$
Navkiran J.
Numerade Educator
Trouble 50
When metallic A is placed in a solution of a salt of metallic B, the surface of metal A changes color. When metal B is placed in acrid solution, gas bubbles form on the surface of the metal. When
metal A is placed in a solution of a salt of metal C, no change is observed in the solution or on the surface of metallic A.
(a) Will metal C crusade formation of H2 when placed in acid solution?
(b) Rank metals A, B, and C in order of decreasing reducing strength.
Ahmed A.
Numerade Educator
Problem 51
When a clean iron nail is placed in an aqueous solution of copper(II) sulfate, the nail becomes coated with a chocolate-brown black material.
(a) What is the fabric coating the iron?
(b) What are the oxidizing and reducing agents?
(c) Can this reaction be made into a voltaic cell?
(d) Write the balanced equation for the reaction.
(e) Summate $E_{\text { cell }}^{\circ}$ for the process.
Ahmed A.
Numerade Educator
Problem 52
(a) How do the relative magnitudes of $Q$ and $K$ relate to the
signs of $\Delta One thousand$ and $E_{\text { cell }} ?$ Explicate.
(b) Can a cell do work when $Q / G>1$ or $Q / K<1 ?$ Explain.
Ahmed A.
Numerade Educator
Problem 53
A voltaic cell consists of $\mathrm{A} / \mathrm{A}^{+}$ and $\mathrm{B} / \mathrm{B}^{+}$ one-half-cells, where
$\mathrm{A}$ and $\mathrm{B}$ are metals and the A electrode is negative. The initial
$\left[\mathrm{A}^{+}\right] /\left[\mathrm{B}^{+}\right]$ is such that $E_{\mathrm{cell}}>E_{\mathrm{prison cell}}^{\circ}$
(a) How exercise $\left[\mathrm{A}^{+}\correct]$ and $\left[\mathrm{B}^{+}\right]$ change as the cell operates?
(b) How does $E_{\text { cell }}$ change as the cell operates?
(c) What is $\left[\mathrm{A}^{+}\correct] /\left[\mathrm{B}^{+}\right]$ when $E_{\text { cell }}=E_{\text { prison cell }}^{\circ}$ ? Explain.
(d) Is it possible for $E_{\text { cell }}$ to be less than $E_{\text { cell }}^{\circ}$ ? Explain.
Prashant B.
Numerade Educator
Problem 54
Explain whether $E_{\text { prison cell }}$ of a voltaic cell will increment or decrease with each of the following changes:
(a) Decrease in prison cell temperature
(b) Increase in [agile ion] in the anode compartment
(c) Increase in [agile ion] in the cathode compartment
(d) Increment in pressure of a gaseous reactant in the cathode
compartment
Prashant B.
Numerade Educator
Problem 55
In a concentration cell, is the more than concentrated electrolyte in the cathode or the anode compartment? Explain.
Ahmed A.
Numerade Educator
Problem 56
What is the value of the equilibrium abiding for the reaction between each pair at $25^{\circ} \mathrm{C} ?$
(a) $\mathrm{Ni}(s)$ and $\mathrm{Ag}^{+}(a q)$
(b) $\mathrm{Fe}(s)$ and $\mathrm{Cr}^{3+}(a q)$
Ahmed A.
Numerade Educator
Problem 57
What is the value of the equilibrium constant for the reaction betwixt each pair at $25^{\circ} \mathrm{C} ?$
(a) $\mathrm{Al}(s)$ and $\mathrm{Cd}^{2+}(a q) \quad$ (b) $\mathrm{I}_{2}(due south)$ and $\mathrm{Br}^{-}(a q)$
Ahmed A.
Numerade Educator
Problem 58
What is the value of the equilibrium constant for the reaction between each pair at $25^{\circ} \mathrm{C} ?$
$\begin{array}{llll}{\text { (a) } \mathrm{Ag}(due south) \text { and } \mathrm{Mn}^{2+}(a q)} & {{ } & {\text { (b) } \mathrm{Cl}_{ii}(k) \text { and } \mathrm{Br}^{-}(a q)} & {{ }\end{array}$
Ahmed A.
Numerade Educator
Problem 59
What is the value of the equilibrium constant for the reaction between each pair at $25^{\circ} \mathrm{C} ?$
$\begin{assortment}{ll}{\text { (a) } \mathrm{Cr}(southward) \text { and } \mathrm{Cu}^{2+}(a q)} & {\text { (b) } \mathrm{Sn}(s) \text { and } \mathrm{Pb}^{2+}(a q)}\end{assortment}$
Ahmed A.
Numerade Educator
Problem 60
Calculate $\Delta G^{\circ}$ for each of the reactions in Problem 21.56
Ahmed A.
Numerade Educator
Problem 61
Summate $\Delta Thou^{\circ}$ for each of the reactions in Problem 21.57
Ahmed A.
Numerade Educator
Problem 62
Calculate $\Delta 1000^{\circ}$ for each of the reactions in Problem 21.58
Ahmed A.
Numerade Educator
Problem 63
Calculate $\Delta Chiliad^{\circ}$ for each of the reactions in Problem 21.59
Ahmed A.
Numerade Educator
Problem 64
What are $E_{\text { cell }}^{\circ}$ and $\Delta G^{\circ}$ of a redox reaction at $25^{\circ} \mathrm{C}$ forwhich $n=1$ and $K=five.0 \times 10^{4} ?$
Ahmed A.
Numerade Educator
Trouble 65
What are $E_{\text { prison cell }}^{\circ}$ and $\Delta G^{\circ}$ of a redox reaction at $25^{\circ} \mathrm{C}$ for which $n=one$ and $K=5.0 \times 10^{-six} ?$
Ahmed A.
Numerade Educator
Problem 66
What are $E_{\text { cell }}^{\circ}$ and $\Delta Chiliad^{\circ}$ of a redox reaction at $25^{\circ} \mathrm{C}$ for which $n=two$ and $K=65 ?$
Ahmed A.
Numerade Educator
Trouble 67
What are $E_{\text { cel }}^{\circ}$ and $\Delta G^{\circ}$ of a redox reaction at $25^{\circ} \mathrm{C}$ for which $northward=two$ and $Yard=0.065 ?$
Ahmed A.
Numerade Educator
Problem 68
A voltaic jail cell consists of a standard reference half-prison cell and a $\mathrm{Cu} / \mathrm{Cu}^{ii+}$ half-cell. Calculate $\left[\mathrm{Cu}^{2+}\right]$ when $E_{\text { prison cell }}$ is 0.22 $\mathrm{5} .$
Ahmed A.
Numerade Educator
Problem 69
$\mathrm{A}$ voltaic cell consists of an $\mathrm{Mn} / \mathrm{Mn}^{2+}$ one-half-cell and a
$\mathrm{Pb} / \mathrm{Pb}^{2+}$ half-cell. Calculate $\left[\mathrm{Lead}^{2+}\correct]$ when $\left[\mathrm{Mn}^{2+}\right]$ is 1.4$Thousand$ and $E_{\text { prison cell }}$ is 0.44 $\mathrm{V} .$
Ahmed A.
Numerade Educator
Problem 70
A voltaic prison cell with $\mathrm{Ni} / \mathrm{Ni}^{2+}$ and $\mathrm{Co} / \mathrm{Co}^{2+}$ half-cells has the following initial concentrations: $\left[\mathrm{Ni}^{ii+}\right]=0.80 M ;\left[\mathrm{Co}^{ii+}\right]=$ 0.20$M .$
(a) What is the initial $E_{\text { prison cell }} ?$
(b) What is $\left[\mathrm{Ni}^{2+}\right]$ when $E_{\text { cell reaches } 0.03 \mathrm{V} ?}$
(c) What are the equilibrium concentrations of the ions?
David C.
Numerade Educator
Problem 71
A voltaic cell with $\mathrm{Mn} / \mathrm{Mn}^{2+}$ and $\mathrm{Cd} / \mathrm{Cd}^{2+}$ half-cells has the post-obit initial concentrations: $\left[\mathrm{Mn}^{2+}\right]=0.090 Chiliad ;\left[\mathrm{Cd}^{ii+}\right]=$ 0.060 $\mathrm{G} .$
(a) What is the initial $E_{\text { cell }} ?$
(b) What is $E_{\text { cell }}$ when $\left[\mathrm{Cd}^{ii+}\right]$ reaches 0.050$One thousand ?$
(c) What is $\left[\mathrm{Mn}^{two+}\right]$ when $E_{\text { cell }}$ reaches 0.055 $\mathrm{V}$ ?
(d) What are the equilibrium concentrations of the ions?
Trouble 72
A voltaic cell consists of two $\mathrm{H}_{2} / \mathrm{H}^{+}$ half-cells. Half-jail cell $\mathrm{A}$ has $\mathrm{H}_{ii}$ at 0.95 atm bubbling into 0.ten $\mathrm{M}$ HCl. Half-jail cell $\mathrm{B}$ has $\mathrm{H}_{ii}$ at 0.threescore $\mathrm{atm}$ bubbles into 2.0 $\mathrm{M}$ HCl. Which one-half-prison cell houses the anode? What is the voltage of the cell?
Ahmed A.
Numerade Educator
Problem 73
A voltaic prison cell consists of two $\mathrm{Sn} / \mathrm{Sn}^{2+}$ one-half-cells, A and B. The electrolyte in $\mathrm{A}$ is 0.13$Chiliad \mathrm{Sn}\left(\mathrm{NO}_{iii}\right)_{ii} .$ The electrolyte in $\mathrm{B}$ is 0.87$Thou \mathrm{Sn}\left(\mathrm{NO}_{3}\right)_{ii}$ . Which one-half-jail cell houses the cathode? What is the voltage of the cell?
Ahmed A.
Numerade Educator
Problem 74
What is the direction of electron flow with respect to the anode and the cathode in a bombardment? Explicate.
Ahmed A.
Numerade Educator
Problem 75
In the everyday batteries used in flashlights, toys, then forth, no salt span is evident. What is used in these cells to split the anode and cathode compartments?
Ahmed A.
Numerade Educator
Trouble 76
Both a D-sized and an AAA-sized alkaline battery accept an output of ane.5 $\mathrm{5}$ . What belongings of the prison cell potential allows this to occur? What is dissimilar nearly these two batteries?
Ahmed A.
Numerade Educator
Trouble 77
Many common electrical devices require the use of more than 1 bombardment
(a) How many alkali metal batteries must be placed in series to light a flashlight with a 6.0 -V bulb?
(b) What is the voltage requirement of a camera that uses half-dozen silvery batteries?
(c) How many volts tin can a car battery deliver if two of its anodel cathode cells are shorted?
Ahmed A.
Numerade Educator
Problem 78
During reconstruction of the Statue of Liberty, Teflon spacers were placed between the iron skeleton and the copper plates that cover the statue. What purpose exercise these spacers serve?
Ahmed A.
Numerade Educator
Problem 79
Why practice steel span-supports rust at the waterline merely not higher up or below information technology?
Ahmed A.
Numerade Educator
Problem 80
After the 1930s, chromium replaced nickel for corrosion resistance and appearance on car bumpers and trim. How does chromium protect steel from corrosion?
Ahmed A.
Numerade Educator
Problem 81
Which of the following metals are suitable for use as sacrificial anodes to protect confronting corrosion of clandestine fe pipes? If any are non suitable, explain why:
(a) Aluminum $\quad$ (b) Magnesium $\quad(\mathrm{c})$ Sodium $\quad$ (d) Lead
(e) Nickel (f) Zinc (yard) Chromium
Ahmed A.
Numerade Educator
Trouble 82
Consider the following general electrolytic prison cell:
(a) At which electrode does oxidation occur?
(b) At which electrode does elemental Yard grade?
(c) At which electrode are electrons being released by ions?
(d) At which electrode are electrons entering the prison cell?
Ahmed A.
Numerade Educator
Problem 83
A voltaic jail cell consists of $\mathrm{Cr} / \mathrm{Cr}^{three+}$ and $\mathrm{Cd} / \mathrm{Cd}^{2+}$ half-cells with all components in their standard states. Afterward x minutes of operation, a sparse coating of cadmium metal has plated out on the cathode. Describe what will happen if you attach the negative terminal of a dry out prison cell (1.5 V) to the cell cathode and the positive terminal to the jail cell anode.
Ahmed A.
Numerade Educator
Problem 84
Why are $E_{\text { half-cell values for the oxidation and reduction of }}$ water different from $E_{\text { half-cell }}^{\circ}$ values for the same processes?
Ahmed A.
Numerade Educator
Problem 85
In an aqueous electrolytic cell, nitrate ions never react at the anode, only nitrite ions practise. Explain.
Ahmed A.
Numerade Educator
Trouble 86
How does overvoltage influence the products in the electrolysis of aqueous salts?
Ahmed A.
Numerade Educator
Problem 87
In the electrolysis of molten NaBr,
(a) What product forms at the anode?
(b) What product forms at the cathode?
David C.
Numerade Educator
Problem 88
In the electrolysis of molten BaI_
(a) What product forms at the negative electrode?
(b) What product forms at the positive electrode?
Ahmed A.
Numerade Educator
Problem 89
In the electrolysis of a molten mixture of $\mathrm{KI}$ and $\mathrm{MgF}_{two}$ place the product that forms at the anode and at the cathode.
Ahmed A.
Numerade Educator
Problem 90
In the electrolysis of a molten mixture of $\mathrm{CsBr}$ and $\mathrm{SrCl}_{2}$ , identify the product that forms at the negative electrode and at the positive electrode.
Ahmed A.
Numerade Educator
Problem 91
1 In the electrolysis of a molten mixture of $\mathrm{NaCl}$ and $\mathrm{CaBr}_{2}$ , place the product that forms at the anode and at the cathode.
Ahmed A.
Numerade Educator
Problem 92
In the electrolysis of a molten mixture of RbF and $\mathrm{CaCl}_{ii}$ , identify the product that forms at the negative electrode and at the positive electrode.
Ahmed A.
Numerade Educator
Problem 93
Which of the following elements can be prepared by electrolysis of their aqueous salts: copper, barium, aluminum, bromine?
Ahmed A.
Numerade Educator
Problem 94
Which of the following elements tin can be prepared by electrolysis of their aqueous salts: strontium, gilt, tin can, chlorine?
Ahmed A.
Numerade Educator
Problem 95
Which of the following elements can be prepared by electrolysis of their aqueous salts: lithium, iodine, zinc, silverish?
Ahmed A.
Numerade Educator
Problem 95
Write a balanced half-reaction for the production that forms at each electrode in the aqueous electrolysis of the following salts:
(a) $\operatorname{ZnBr}_{ii} ;(\mathrm
{b}) \mathrm{Cu}\left(\mathrm{HCO}_{3}\right)_{2}$
Ahmed A.
Numerade Educator
Problem 96
Which of the post-obit elements can be prepared past electrolysis of their aqueous salts: fluorine, manganese, iron, cadmium?
Ahmed A.
Numerade Educator
Problem 97
Write a balanced one-half-reaction for the production that forms at each electrode in the aqueous electrolysis of the following salts:
(a) LiF; (b) SnSO.
Ahmed A.
Numerade Educator
Problem 99
Write a balanced half-reaction for the product that forms at each electrode in the aqueous electrolysis of the following salts:
(a) $\mathrm{Cr}\left(\mathrm{NO}_{3}\right)_{iii} ;(\mathrm{b}) \mathrm{MnCl}_{2}$
Ahmed A.
Numerade Educator
Trouble 100
Write a balanced half-reaction for the product that forms at each electrode in the aqueous electrolysis of the following salts:
(a) $\mathrm{FeI}_{2} ;(\mathrm{b}) \mathrm{Chiliad}_{three} \mathrm{PO}_{4}$
Ahmed A.
Numerade Educator
Problem 101
Electrolysis of molten $\mathrm{MgCl}_{2}$ is the concluding production step in the isolation of magnesium from seawater past the Dow process
(Section 22.iv$) .$ Assuming that 45.half-dozen $\mathrm{g}$ of Mg metal forms,
(a) How many moles of electrons are required?
(b) How many coulombs are required?
(c) How many amps will produce this amount in 3.50 $\mathrm{h}$ ?
Ahmed A.
Numerade Educator
Problem 102
Electrolysis of molten NaCl in a Downs cell is the major isolation pace in the production of sodium metal (Department 22.4$)$ Bold that 215 one thousand of Na metallic forms,
(a) How many moles of electrons are required?
(b) How many coulombs are required?
(c) How many amps will produce this amount in 9.50 $\mathrm{h}$ ?
Ahmed A.
Numerade Educator
Trouble 103
How many grams of radium can form by passing 235 C through an electrolytic cell containing a molten radium salt?
Ahmed A.
Numerade Educator
Trouble 104
How many grams of aluminum tin grade by passing 305 C through an electrolytic jail cell containing a molten aluminum salt?
Ahmed A.
Numerade Educator
Problem 105
How many seconds does it have to deposit 65.5 $\mathrm{g}$ of $\mathrm{Zn}$ on a steel gate when 21.0 $\mathrm{A}$ is passed through a $\mathrm{ZnSO}_{4}$ solution?
Ahmed A.
Numerade Educator
Trouble 106
How many seconds does it accept to eolith one.63 $\mathrm{g}$ of $\mathrm{Ni}$ on a decorative drawer handle when xiii.7 $\mathrm{A}$ is passed through a $\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{ii}$ solution?
Ahmed A.
Numerade Educator
Trouble 107
A professor adds $\mathrm{Na}_{2} \mathrm{SO}_{4}$ to water to facilitate its electrolysis in a lecture demonstration. (a) What is the purpose of the $\mathrm{Na}_{two} \mathrm{SO}_{4} ?(\mathrm{b})$ Why is the water electrolyzed instead of the salt?
Ahmed A.
Numerade Educator
Problem 108
Subterranean brines in parts of the Us are rich in iodides and bromides and serve as an industrial source of these elements. In ane recovery method, the brines are evaporated to dryness and then melted and electrolyzed. Which element of group vii is more than likely to grade from this treatment? Why?
Ahmed A.
Numerade Educator
Problem 109
Zinc plating (galvanizing) is an important means of corrosion protection. Although the process is washed customarily by dipping the object into molten zinc, the metal can also be electroplated from aqueous solutions. How many grams of zinc can be deposited on a steel tank from a $\mathrm{ZnSO}_{4}$ solution when a $0.855-\mathrm{A}$ current flows for 2.l days?
Ahmed A.
Numerade Educator
Problem 110
The $\mathrm{MnO}_{two}$ used in alkaline batteries can exist produced by an electrochemical process of which i half-reaction is
$$
\mathrm{Mn}^{2+}(a q)+2 \mathrm{H}_{2} \mathrm{O}(fifty) \longrightarrow \mathrm{MnO}_{2}(south)+4 \mathrm{H}^{+}(a q)+2 \mathrm{e}^{-}
$$
If a electric current of 25.0 $\mathrm{A}$ is used, how many hours are needed to produce one.00 $\mathrm{kg}$ of $\mathrm{MnO}_{2} ?$ At which electrode is the MnO $_{2}$ formed?
Prashant B.
Numerade Educator
Trouble 111
Auto manufacturers are developing engines that utilize $\mathrm{H}_{ii}$ as fuel. In Iceland, Sweden, and other parts of Scandinavia, where hydroelectric plants produce inexpensive electric ability, the $\mathrm{H}_{2}$ can exist made industrially by the electrolysis of h2o.
(a) How many coulombs are needed to produce $three.v \times x^{half-dozen} \mathrm{L}$ of $\mathrm{H}_{2}$
gas at 12.0 $\mathrm{atm}$ and $25^{\circ} \mathrm{C} ?$ (Presume that the ideal gas law applies.)
(b) If the coulombs are supplied at $one.44 \mathrm{Five},$ how many joules are produced?
(c) If the combustion of oil yields $4.0 \times 10^{4} \mathrm{kJ} / \mathrm{kg}$ , what mass of oil
must exist burned to yield the number of joules in part (b)?
Sean O.
Numerade Educator
Problem 113
An inexpensive and accurate method of measuring the quantity of electricity flowing through a circuit is to pass the current through a solution of a metal ion and weigh the metal deposited. A silver electrode immersed in an Ag' solution weighs 1.7854 thou before the current has passed and weighs 1.8016 $\mathrm{thousand}$ after the current has passed. How many coulombs have passed?
Ahmed A.
Numerade Educator
Problem 114
Brass, an alloy of copper and zinc, can be produced by simultaneously electroplating the ii metals from a solution con- ctaining their $2+$ ions. If 65.0$\%$ of the total electric current is used to plate
copper, while 35.0$\%$ goes to plating zinc, what is the mass per centum of copper in the brass?
Ahmed A.
Numerade Educator
Problem 115
A thin circular disk earring 4.00 $\mathrm{cm}$ in diameter is plated with a coating of aureate 0.25 $\mathrm{mm}$ thick from an Au $^{3+}$ bathroom.
(a) How many days does it take to deposit the gold on one side of one earring if the current is 0.013 $\mathrm{A}\left(d \text { of gold }=19.3 \mathrm{g} / \mathrm{cm}^{3}\correct) ?$
(b) How many days does information technology take to deposit the gilt on both sides of the pair of earrings?
(c) If the price of gold is $\$ 1595$ per troy ounce $(31.10 \mathrm{thou}),$ what is the total price of the gold plating?
David C.
Numerade Educator
Problem 116
(a) How many minutes does information technology take to form 10.0 $\mathrm{50}$ of $\mathrm{O}_{2}$ measured at 99.8 $\mathrm{kPa}$ and $28^{\circ} \mathrm{C}$ from water if a current of 1.3 $\mathrm{A}$ passes through the electrolytic cell?
(b) What mass of $\mathrm{H}_{2}$ forms?
Problem 117
Trains powered past electricity, including subways, use direct current. One conductor is the overhead wire (or "third rails" for subways), and the other is the rails upon which the wheels run. The rails are on supports in contact with the basis. To minimize corrosion, should the overhead wire or the rails be continued to the positive terminal? Explicate.
Prashant B.
Numerade Educator
Trouble 118
A argent push battery used in a lookout man contains 0.75 g of zinc and tin can run until 80$\%$ of the zinc is consumed.
(a) For how many days can the battery produce a current of 0.85 microamps $\left(10^{-6} \text { amps)? }\right.$
(b) When the battery dies, 95$\%$ of the $\mathrm{Ag}_{ii} \mathrm{O}$ has been consumed. How many grams of Ag were used to make the battery?
(c) If Ag costs $\$ 23.00$ per troy ounce $(31.10 \mathrm{chiliad})$ , what is the cost of the Ag consumed each day the scout runs?
Problem 119
Like whatever piece of apparatus, an electrolytic cell operates at less than 100$\%$ efficiency. A cell depositing Cu from a Cu't bath operates for x $\mathrm{h}$ with an average current of five.8 $\mathrm{A} .$ If 53.four $\mathrm{g}$ of copper is deposited, at what efficiency is the cell operating?
Prashant B.
Numerade Educator
Problem 120
Commercial electrolysis is performed on both molten NaCl and aqueous NaCl solutions. Identify the anode product, cathode product, species reduced, and species oxidized for the (a) molten electrolysis and (b) aqueous electrolysis.
Ahmed A.
Numerade Educator
Trouble 121
To examine the effect of ion removal on jail cell voltage, a chemist constructs two voltaic cells, each with a standard hydrogen electrode in one compartment. One jail cell also contains a $\mathrm{Pb} / \mathrm{Pb}^{2+}$ half-cell; the other contains a $\mathrm{Cu} / \mathrm{Cu}^{ii+}$ half-cell.
(a) What is $Eastward^{\circ}$ of each cell at 298 $\mathrm{K}$ ?
(b) Which electrode in each cell is negative?
(c) When $\mathrm{Na}_{2}$ S solution is added to the Pb $^{2+}$ electrolyte, solid PbS
forms. What happens to the jail cell voltage?
(d) When sufficient $\mathrm{Na}_{ii} \mathrm{South}$ is added to the $\mathrm{Cu}^{ii+}$ electrolyte, CuS
forms and $\left[\mathrm{Cu}^{two+}\right]$ drops to $one \times x^{-16} \mathrm{Thousand} .$ Find the prison cell voltage.
Problem 122
Electrodes used in electrocardiography are disposable, and many of them comprise silver. The metal is deposited in a sparse layer on a pocket-sized plastic "push button," so some is converted to
AgCl:
$$
\mathrm{Ag}(s)+\mathrm{Cl}^{-}(a q) \rightleftharpoons \mathrm{AgCl}(s)+\mathrm{e}^{-}
$$
(a) If the surface expanse of the button is ii.0 $\mathrm{cm}^{2}$ and the thickness of
the argent layer is $7.five \times 10^{-half dozen} \mathrm{m}$ , summate the book (in $\mathrm{cm}^{3} )$ of
Ag used in i electrode.
(b) The density of silver metal is ten.5 $\mathrm{m} / \mathrm{cm}^{three} .$ How many grams of
silvery are used per electrode?
(c) If Ag is plated on the button from an Ag^{+} solution with a
current of 12.0 $\mathrm{mA}$ , how many minutes does the plating take?
(d) If majority argent costs $\$ 28.93$ per troy ounce $(31.x \mathrm{g}),$ what is the
cost (in cents) of the silver in one disposable electrode?
Problem 123
Commercial aluminum production is done past electrolysis of a bath containing $\mathrm{Al}_{2} \mathrm{O}_{3}$ dissolved in molten $\mathrm{Na}_{3} \mathrm{AlF}_{half dozen} .$ Why isn't information technology done by electrolysis of an aqueous AlCl_ solution?
Ahmed A.
Numerade Educator
Problem 124
Comparing the standard electrode potentials $\left(Eastward^{\circ}\right)$ of the Group 1 $\mathrm{A}(ane)$ metals Li, Na, and $\mathrm{1000}$ with the negative of their kickoff ionization energies reveals a discrepancy:
Ionization process reversed: $\mathrm{Thou}^{+}(g)+\mathrm{e}^{-} \rightleftharpoons \mathrm{M}(thou) \quad(-\mathrm{IE})$
Electrode reaction: $\quad \quad \mathrm{M}^{+}(a q)+\mathrm{e}^{-} \rightleftharpoons \mathrm{Yard}(south) \quad\left(E^{\circ}\right)$
Note that the electrode potentials do not subtract smoothly down the group, while the ionization energies practise. Yous might wait that if information technology is more difficult to remove an electron from an atom to form a gaseous ion (larger IE), then it would be less difficult to add an electron to an aqueous ion to form an atom (smaller $E^{\circ} ),$ yet Lit $(a q)$ is more difficult to reduce than $\mathrm{Na}^{+}(a q) .$ Applying Hess'south law, utilize an arroyo similar to a Built-in-Haber cycle to intermission down the process occurring at the electrode into iii steps and characterization the energy involved in each footstep. How can you account for the discrepancy?
Prashant B.
Numerade Educator
Problem 125
In Appendix $D,$ standard electrode potentials range from about $+3 \mathrm{Five}$ to $-3 \mathrm{V}$ . Thus, it might seem possible to utilise a half- cell from each cease of this range to construct a cell with a voltage of approximately 6 $\mathrm{5}$ . However, most commercial aqueous voltaic cells have $Eastward^{\circ}$ values of $i.5-two \mathrm{V} .$ Why are there no aqueous cells with significantly higher potentials?
Ahmed A.
Numerade Educator
Problem 126
Tin is used to glaze "tin" cans used food storage. If the can is scratched and the iron of the can exposed, volition the iron corrode more or less apace than if the tin were not present? Within the can, the tin itself is coated with a clear varnish. Explain.
Ahmed A.
Numerade Educator
Problem 127
Commercial electrolytic cells for producing aluminum operate at 5.0 $\mathrm{V}$ and $100,000 \mathrm{A}$ .
(a) How long does it have to produce exactly 1 metric ton
$(one thousand \mathrm{kg})$ of aluminum?
(b) How much electrical ability (in kilowatt-hours, kW h) is used
$\left(1 \mathrm{Westward}=1 \mathrm{J} / \mathrm{s} ; one \mathrm{kW} \cdot \mathrm{h}=3.6 \times 10^{3} \mathrm{kJ}\right) ?$
(c) If electricity costs $\$ 0.123$ per kW h and cell efficiency is $90 . \%$ ,
what is the toll of electricity to produce exactly 1 lb of aluminum?
Problem 128
Magnesium bars are connected electrically to underground iron pipes to serve equally sacrificial anodes.
(a) Do electrons flow from the bar to the pipe or the contrary?
(b) A 12 -kg Mg bar is attached to an iron pipe, and it takes viii.5 yr for the Mg to be consumed. What is the average current flowing between the Mg and the Fe during this period?
Prashant B.
Numerade Educator
Problem 129
Bubbles of $\mathrm{H}_{two}$ form when metal $\mathrm{D}$ is placed in hot $\mathrm{H}_{2} \mathrm{O}$ . No reaction occurs when $\mathrm{D}$ is placed in a solution of a salt of
metal $\mathrm{East}$ , but $\mathrm{D}$ is discolored and coated immediately when placed in a solution of a salt of metallic F. What happens if $\mathrm{E}$ is placed in a solution of a salt of metal $\mathrm{F}$ ? Rank metals $\mathrm{D}, \mathrm{Eastward},$ and $\mathrm{F}$ in gild of increasing reducing forcefulness.
Ahmed A.
Numerade Educator
Problem 130
In addition to reacting with gold (run into Problem 21.21$)$ , aqua regia is used to bring other precious metals into solution. Balance the skeleton equation for the reaction with Pt:
$$
\mathrm{Pt}(s)+\mathrm{NO}_{3}^{-}(a q)+\mathrm{Cl}^{-}(a q) \longrightarrow \mathrm{PtCl}_{six}^{two-}(a q)+\mathrm{NO}(g)
$$
Ahmed A.
Numerade Educator
Problem 131
The following reactions are used in batteries:
$\mathrm{I} \quad 2 \mathrm{H}_{two}(thou)+\mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{H}_{2} \mathrm{O}(l) \quad E_{\mathrm{cell}}=1.23 \mathrm{Five}$
$\begin{aligned} \text { II } \quad \mathrm{Pb}(s)+\mathrm{PbO}_{2}(south)+ii \mathrm{H}_{2} \mathrm{SO}_{4}(a q) & \longrightarrow \\ 2 \mathrm{PbSO}_{4}(s)+2 \mathrm{H}_{2} \mathrm{O}(fifty) & E_{\mathrm{cell}}=2.04 \mathrm{5} \terminate{aligned}$
III $ii \mathrm{Na}(50)+\mathrm{FeCl}_{two}(s) \longrightarrow two \mathrm{NaCl}(due south)+\mathrm{Iron}(s) \quad E_{\mathrm{cell}}=2.35 \mathrm{Five}$
Reaction I is used in fuel cells, II in the auto lead-acrid bombardment, and Three in an experimental high-temperature battery for powering electrical vehicles. The aim is to obtain as much work as possible from a cell, while keeping its weight to a minimum.
(a) In each cell, discover the moles of electrons transferred and $\Delta G .$
(b) Calculate the ratio, in $\mathrm{kJ} / \mathrm{g},$ of $w_{\text { max }}$ to mass of reactants for each of the cells. Which has the highest ratio, which the lowest, and why? (Note: For simplicity, ignore the masses of prison cell components that do not announced in the cell as reactants, including electrode
materials, electrolytes, separators, cell casing, wiring, etc.)
Trouble 132
A current is applied to ii electrolytic cells in series. In the first, silver is deposited; in the second, a zinc electrode is consumed. How much Ag is plated out if 1.two $\mathrm{k}$ of Zn dissolves?
Prashant B.
Numerade Educator
Problem 133
You are investigating a particular chemic reaction. Country all the types of data available in standard tables that enable yous to calculate the equilibrium constant for the reaction at 298 $\mathrm{Chiliad}$ .
Prashant B.
Numerade Educator
Problem 134
In an electric power plant, personnel monitor the $\mathrm{O}_{ii}$ content of boiler feed water to prevent corrosion of the boiler tubes. Why does Fe corrode faster in steam and hot water than in cold
water?
Ahmed A.
Numerade Educator
Trouble 135
A voltaic cell using $\mathrm{Cu} / \mathrm{Cu}^{2+}$ and $\mathrm{Sn} / \mathrm{Sn}^{2+}$ half-cells is gear up up at standard conditions, and each compartment has a book of
345 $\mathrm{mL}$ . The cell delivers 0.17 $\mathrm{A}$ for 48.0 $\mathrm{h}$ . (a) How many grams
of $\mathrm{Cu}(s)$ are deposited? (b) What is the $\left[\mathrm{Cu}^{ii+}\correct]$ remaining?
Ahmed A.
Numerade Educator
Problem 136
If the $E_{\text { prison cell }}$ of the following cell is $0.915 \mathrm{V},$ what is the $\mathrm{pH}$ in the anode compartment?
$$
\mathrm{Pt}(s)\left|\mathrm{H}_{2}(1.00 \mathrm{atm})\right| \mathrm{H}^{+}(a q) \| \mathrm{Ag}^{+}(0.100 Chiliad) | \mathrm{Ag}(s)
$$
Ahmed A.
Numerade Educator
Problem 137
From the skeleton equations below, create a listing of counterbalanced half-reactions in which the strongest oxidizing agent is on height and the weakest is on the lesser:
$$
\brainstorm{array}{c}{\mathrm{U}^{three+}(a q)+\mathrm{Cr}^{3+}(a q) \longrightarrow \mathrm{Cr}^{2+}(a q)+\mathrm{U}^{4+}(a q)} \\ {\mathrm{Fe}(s)+\mathrm{Sn}^{2+}(a q) \longrightarrow \mathrm{Sn}(s)+\mathrm{Fe}^{ii+}(a q)} \\ {\mathrm{Fe}(s)+\mathrm{U}^{4+}(a q) \longrightarrow \text { no reaction }} \\ {\mathrm{Cr}^{3+}(a q)+\mathrm{Fe}(s) \longrightarrow \mathrm{Cr}^{2+}(a q)+\mathrm{Fe}^{2+}(a q)} \\ {\mathrm{Cr}^{2+}(a q)+\mathrm{Sn}^{2+}(a q) \longrightarrow \mathrm{Sn}(due south)+\mathrm{Cr}^{three+}(a q)}\end{array}
$$
Ahmed A.
Numerade Educator
Trouble 138
Y'all are given the following three half-reactions:
(1) $\mathrm{Fe}^{3+}(a q)+\mathrm{e}^{-} \Longrightarrow \mathrm{Atomic number 26}^{2+}(a q)$
(2) $\mathrm{Fe}^{two+}(a q)+2 \mathrm{e}^{-} \rightleftharpoons \mathrm{Fe}(s)$
(3) $\mathrm{Fe}^{iii+}(a q)+iii \mathrm{e}^{-} \Longrightarrow \mathrm{Atomic number 26}(southward)$
(a) Use $E_{\text { half-prison cell }}^{\circ}$ values for $(1)$ and $(2)$ to find $E_{\text { one-half-cell }}^{\circ}$ for $(three)$
(b) Calculate $\Delta G^{\circ}$ for $(1)$ and $(two)$ from their $E_{\text { half-cell values. }}^{\text { olues. }}$
(c) Calculate $\Delta K^{\circ}$ for $(3)$ from $(1)$ and $(2)$
(d) Calculate $E_{\text { half-jail cell }}^{\circ}$ for $(three)$ from its $\Delta G^{\circ} .$
(e) What is the relationship between the $E_{\text { half-jail cell }}^{\circ}$ values for $(i)$ and
(2) and the $E_{\text { one-half-prison cell }}^{\circ}$ value for $(three) ?$
Problem 139
Apply the one-half-reaction method to balance the equation for the conversion of ethanol to acetic acid in acid solution:
$$
\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}+\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-} \longrightarrow \mathrm{CH}_{3} \mathrm{COOH}+\mathrm{Cr}^{3+}
$$
Ahmed A.
Numerade Educator
Problem 140
When zinc is refined by electrolysis, the desired one-half- reaction at the cathode is
$$
\mathrm{Zn}^{2+}(a q)+2 \mathrm{e}^{-} \longrightarrow \mathrm{Zn}(southward)
$$
A competing reaction, which lowers the yield, is the formation of hydrogen gas:
$$
ii \mathrm{H}^{+}(a q)+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_{2}(g)
$$
If 91.fifty$\%$ of the current flowing results in zinc beingness deposited, while 8.l$\%$ produces hydrogen gas, how many liters of $\mathrm{H}_{ii}$ , measured at STP, class per kilogram of zinc?
Problem 141
21.141 $\mathrm{A}$ chemist designs an ion-specific probe for measur-
ing [Ag'l in an NaCl solution saturated with AgCl. Ane one-half-
cell has an Ag-wire electrode immersed in the unknown
AgCl-saturated $\mathrm{NaCl}$ solution. It is connected through a table salt
bridge to the other half-cell, which has a calomel reference electrode [a platinum wire immersed in a paste of mercury and calo-
mel $\left(\mathrm{Hg}_{2} \mathrm{Cl}_{2}\right) ]$ in a saturated $\mathrm{KCl}$ solution. The measured $E_{\mathrm{cell}}$ is
0.060 $\mathrm{V} .$
$\begin{assortment}{fifty}{\text { (a) Given the following standard half-reactions, calculate }\left[\mathrm{Ag}^{+}\right] .} \\ {\text { Calomel: } \mathrm{Hg}_{ii} \mathrm{Cl}_{2}(s)+2 \mathrm{east}^{-} \longrightarrow} \\ {\text { Silver: } \mathrm{Ag}^{+}(a q)+\mathrm{due east}^{-} \longrightarrow \mathrm{Ag}(s)} & {East^{\circ}=0.lxxx \mathrm{V}}\end{array}$
(Hint: Assume that $\left[\mathrm{Cl}^{-}\right]$ is so high that information technology is essentially constant.)
(b) A mining engineer wants an ore sample analyzed with the
Ag'-selective probe. Subsequently pretreating the ore sample, the chemist
measures the cell voltage as 0.53 $\mathrm{V} .$ What is $\left[\mathrm{Ag}^{+}\right] ?$
Problem 142
Use Appendix D to calculate the $K_{\mathrm{sp}}$ of $\mathrm{AgCl}$
Ahmed A.
Numerade Educator
Trouble 143
21.143 Black-and-white photographic movie is coated with silverish halides. Considering silver is expensive, the manufacturer monitors the Ag' content of the waste material stream, [Ag $^{+} ]_{\text { waste }}$ from the plant with an Ag'-selective electrode at $25^{\circ} \mathrm{C}$ . A stream of known Ag^{+} concentration, $\left[\mathrm{Ag}^{+}\right]_{\text { standard }},$ is passed over the electrode in plow with the waste matter stream and the information recorded past a computer.
(a) Write the equations relating the nonstandard cell potential to the standard cell potential and [Ag' ] for each solution.
(b) Combine these into a unmarried equation to notice $\left[\mathrm{Ag}^{+}\right]_{\text { waste material }}$
(c) Rewrite the equation from office (b) to find $\left[\mathrm{Ag}^{+}\right]_{\text { waste material }}$ in $\mathrm{ng} / \mathrm{50}$ .
(d) If $E_{\text { waste }}$ is 0.003 Five college than $E_{\text { standard }},$ and the standard
solution contains 1000 . ng/L, what is $\left[\mathrm{Ag}^{+}\correct]_{\text { waste product }} ?$
(due east) Rewrite the equation from part (b) to notice $\left[\mathrm{Ag}^{+}\correct]_{\text { waste for a }}$
organization in which $T$ changes and $T_{\text { waste product }}$ and $T_{\text { standard }}$ may be different.
Problem 144
Calculate the $K_{\mathrm{f}}$ of $\mathrm{Ag}\left(\mathrm{NH}_{three}\right)_{ii}^{+}$ from
$\mathrm{Ag}^{+}(a q)+\mathrm{e}^{-} \rightleftharpoons \mathrm{Ag}(s) \quad East^{\circ}=0.80 \mathrm{Five}$
$\operatorname{Ag}\left(\mathrm{NH}_{3}\right)_{2}^{+}(a q)+\mathrm{e}^{-} \rightleftharpoons \mathrm{Ag}(s)+2 \mathrm{NH}_{3}(a q) \qquad Eastward^{\circ}=0.37 \mathrm{V}$
Ahmed A.
Numerade Educator
Trouble 145
Fifty-fifty though the toxicity of cadmium has become a concern, nickel-cadmium (nicad) batteries are nevertheless used usually in many devices. The overall cell reaction is
$$
\mathrm{Cd}(southward)+2 \mathrm{NiO}(\mathrm{OH})(south)+ii \mathrm{H}_{two} \mathrm{O}(l) \longrightarrow
$$
$$
2 \mathrm{Ni}(\mathrm{OH})(due south)+\mathrm{Cd}(\mathrm{OH})_{2}(due south)
$$
A sure nicad battery weighs 18.3 $\mathrm{g}$ and has a capacity of
$300 . \mathrm{mA} \cdot \mathrm{h}$ (that is, the prison cell can store charge equivalent to a current
of $300 .$ mA flowing for i $\mathrm{h}$ ).
(a) What is the capacity of this prison cell in coulombs?
(b) What mass of reactants is needed to deliver $300 . \mathrm{mA}$ - h?
(c) What percent of the prison cell mass consists of reactants?
Rashmi Southward.
Numerade Educator
Trouble 146
The zinc-air battery is a less expensive alternative to silver batteries for use in hearing aids. The cell reaction is
$$
2 \mathrm{Zn}(s)+\mathrm{O}_{2}(g) \longrightarrow ii \mathrm{ZnO}(s)
$$
A new battery weighs 0.275 g. The zinc accounts for exactly $\frac{one}{10}$ of the mass, and the oxygen does not contribute to the mass because information technology is supplied by the air.
(a) How much electricity (in $\mathrm{C} )$ tin the battery deliver?
(b) How much costless energy (in $\mathrm{J} )$ is released if $E_{\text { cell }}$ is 1.3 $\mathrm{Five}$ ?
Problem 147
Employ Appendix $D$ to create an activity series of Mn, Fe, Ag, Sn, Cr, Cu, Ba, Al, Na, Hg, Ni, Li, Au, Zn, and Pb. Rank these metals in gild of decreasing reducing strength, and divide them into 3 groups: those that readapt $\mathrm{H}_{two}$ from h2o, those that readapt $\mathrm{H}_{2}$ from acid, and those that cannot readapt $\mathrm{H}_{ii} .$
Problem 148
Both Ti and $5$ are reactive plenty to readapt $\mathrm{H}_{2}$ from water. The departure in their $E_{\text { half-prison cell values is } 0.43}$ V.\mathrm Given
$$
\mathrm{V}(south)+\mathrm{Cu}^{two+}(a q) \longrightarrow \mathrm{V}^{2+}(a q)+\mathrm{Cu}(s) \quad \Delta Grand^{\circ}=-298 \mathrm{kJ} / \mathrm{mol}
$$
apply Appendix D to calculate the $E_{\text { half-cell }}^{\circ}$ values for $\mathrm{V}$ and Ti.
Prashant B.
Numerade Educator
Problem 149
For the reaction
$$
\mathrm{S}_{4} \mathrm{O}_{6}^{two-}(a q)+2 \mathrm{I}^{-}(a q) \longrightarrow \mathrm{I}_{ii}(south)+\mathrm{S}_{2} \mathrm{O}_{three}^{2-}(a q)
$$
$$
\Delta G^{\circ}=87.viii \mathrm{kJ} / \mathrm{mol}
$$
(a) Identify the oxidizing and reducing agents. (b) Calculate $E_{\text { cell. }}^{\circ}$
(c) For the reduction half-reaction, write a balanced equation, give
the oxidation number of each chemical element, and summate $E_{\text { half prison cell. }}^{\circ}$
Trouble 150
Ii concentration cells are prepared, both with 90.0 $\mathrm{mL}$ of 0.0100$M \mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}$ and a Cu bar in each half-prison cell.
(a) In the first concentration cell, ten.0 $\mathrm{mL}$ of 0.500 $\mathrm{MNH}_{3}$ is added
to one half-prison cell; the complex ion $\mathrm{Cu}\left(\mathrm{NH}_{iii}\right)_{4}^{2+}$ forms, and $E_{\mathrm{cell}}$ is 0.129 $\mathrm{V} .$ Calculate $K_{\mathrm{f}}$ for the formation of the complex ion.
(b) Calculate $E_{\text { prison cell }}$ when an additional 10.0 $\mathrm{mL}$ of 0.500 $\mathrm{Thousand} \mathrm{NH}_{3}$ is added.
(c) In the second concentration cell, 10.0 $\mathrm{mL}$ of 0.500 $\mathrm{Thousand}$ NaOH is added to i one-half-cell; the precipitate $\mathrm{Cu}(\mathrm{OH})_{2}$ forms $\left(K_{\mathrm{sp}}=\right.$ $2.2 \times 10^{-20} ) .$ Calculate $E_{\mathrm{prison cell}}^{\circ}$
(d) What would the molarity of NaOH have to be for the addition of x.0 $\mathrm{mL}$ to event in an $E_{\mathrm{cell}}^{\mathrm{o}}$ of 0.340 $\mathrm{V} ?$
Trouble 151
Two voltaic cells are to be joined and so that ane will run the other as an electrolytic cell. In the get-go jail cell, ane half-cell has Au foil in $1.00 M \mathrm{Au}\left(\mathrm{NO}_{three}\right)_{3},$ and the other half-cell has a Cr bar in 1.00$M \mathrm{Cr}\left(\mathrm{NO}_{3}\correct)_{3} .$ In the second cell, one half-cell has a Co bar in $ane.00 K \mathrm{Co}\left(\mathrm{NO}_{3}\right)_{ii},$ and the other half-cell has a $\mathrm{Zn}$ bar in 1.00 $\mathrm{1000}$$\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}$
(a) Calculate $E_{\text { cell }}^{\circ}$ for each prison cell.
(b) Calculate the total potential if the two cells are connected as voltaic cells in series.
(c) When the electrode wires are switched in one of the cells, which prison cell will run as the voltaic prison cell and which as the electrolytic cell?
(d) Which metallic ion is being reduced in each cell?
(e) If ii.00 1000 of metal plates out in the voltaic jail cell, how much metallic ion plates out in the electrolytic cell?
Problem 152
A voltaic cell has one half-jail cell with a Cu bar in a 1.00$M$ $\mathrm{Cu}^{2+}$ common salt, and the other half-cell with a Cd bar in the aforementioned volume of a 1.00 $\mathrm{K} \mathrm{Cd}^{ii+}$ salt.
(a) Find $E_{\text { prison cell }}^{\circ}, \Delta K^{\circ},$ and $K$
(b) As the prison cell operates, $\left[\mathrm{Cd}^{ii+}\right]$ increases ; detect $E_{\text { cell }}$ and $\Delta Chiliad$ when $\left[\mathrm{Cd}^{2+}\right]$ is 1.95 $\mathrm{M} .$
(c) Notice $E_{\text { cell }}, \Delta 1000,$ and $\left[\mathrm{Cu}^{two+}\right]$ at equilibrium.
Problem 153
Gasoline is a mixture of hydrocarbons, merely the rut released when information technology burns is close to that of octane, $\mathrm{C}_{8} \mathrm{H}_{xviii}(50)\left(\Delta H_{\mathrm{f}}^{\circ}=\right.$ $-250.1 \mathrm{kJ} / \mathrm{mol} ) .$ Research is underway to use $\mathrm{H}_{2}$ from the electrolysis of h2o in fuel cells to power cars instead of gasoline.
(a) Calculate $\Delta H^{\circ}$ when 1.00 gal of gasoline $(d=0.7028 \mathrm{g} / \mathrm{mL})$
burns to produce carbon dioxide gas and water vapor.
(b) How many liters of $\mathrm{H}_{ii}$ at $25^{\mathrm{C}} \mathrm{C}$ and 1.00 atm must burn to
produce this quantity of free energy?
(c) How long would it take to produce this corporeality of $\mathrm{H}_{2}$ by electrolysis with a current of $1.00 \times 10^{3} \mathrm{A}$ at vi.00 $\mathrm{Five}$ ?
(d) How much power in kilowatt-hours (kW. h) is required to generate this corporeality of $\mathrm{H}_{two} ?(one \mathrm{W}=1 \mathrm{J} / \mathrm{due south}, 1 \mathrm{J}=i \mathrm{C} \cdot \mathrm{Five}, \text { and }$ $1 \mathrm{kW} \cdot \mathrm{h}=three.half-dozen \times 10^{half dozen} \mathrm{J} . )$
(e) If the prison cell is 88.0$\%$ efficient and electricity costs $\$ 0.123$ per
$\mathrm{kW} \cdot \mathrm{h},$ what is the cost of producing the amount of $\mathrm{H}_{ii}$ equivalent to 1.00 gal of gasoline?
Source: https://www.numerade.com/books/chapter/electrochemistry-chemical-change-and-electrical-work/
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