Chapter 8

Astudent made the followingobservations in the laboratory: (I) Clean copper metal did not react with \(1 \mathrm{M}-\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}\) solution. (II) Clean lead metal dissolves in \(1 \mathrm{M}\) \(-\mathrm{AgNO}_{3}\) solution and crystals of Ag metal appeared. (III) Clean silver metal did not react with \(1 \mathrm{M}-\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}\) solution. The order of decreasing reducing character of the three metals is (a) \(\mathrm{Cu}>\mathrm{Pb}>\mathrm{Ag}\) (b) \(\mathrm{Cu}>\mathrm{Ag}>\mathrm{Pb}\) (c) \(\mathrm{Pb}>\mathrm{Cu}>\mathrm{Ag}\) (d) \(\mathrm{Pb}>\mathrm{Ag}>\mathrm{Cu}\)

We have an oxidation-reduction system: \(\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}+\mathrm{e}^{-} \rightleftharpoons\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{4-}\) \(E^{\circ}=+0.36 \mathrm{~V}\). The ratio of concentrations of oxidized and reduced from at which the potential of the system becomes \(0.24 \mathrm{~V}\), is [Given: \(2.303 R T / F=0.06\) ) (a) \(2: 1\) (b) \(1: 2\) (c) \(1: 20\) (d) \(1: 100\)

Indicator electrode is (a) SHE (b) Calomel electrode (c) \(\mathrm{Ag} / \mathrm{AgCl}\) electrode (d) Quinhydrone electrode

The standard reduction potential for the process: \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}+\mathrm{e}^{-} \rightarrow\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) is \(1.8 \mathrm{~V}\). The standard reduction potential for the process: \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+}+\mathrm{e}^{-}\) \(\rightarrow\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}\) is \(0.1 \mathrm{~V} .\) Which of the complex ion, \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) or \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}\) can be oxidized to the corresponding cobalt (III) complex, by oxygen, in basic medium, under standard condition? \(\left[\right.\) Given: \(\left.E_{\mathrm{O}_{2} / \mathrm{OH}^{-}}^{\circ}=0.4 \mathrm{~V}\right]\) (a) \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) (b) \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}\) (c) both (d) none of these

The position of some metals in the electrochemical series in decreasing electropositive character is given as: \(\mathrm{Mg}>\mathrm{Al}>\mathrm{Zn}>\mathrm{Cu}>\mathrm{Ag} .\) What will happen if a copper spoon is used to stira solution of aluminium nitrate? (a) The spoon will get coated with aluminium. (b) An alloy of copper and aluminium is formed. (c) The solution becomes blue. (d) No chemical change will take place.

For a electrochemical cell \(\mathrm{Zn} \mid \mathrm{Zn}^{2+}\left(\mathrm{C}_{1}\right.\) M) \(\| \mathrm{Cu}^{2+}\left(\mathrm{C}_{2} \mathrm{M}\right) \mid \mathrm{Cu}\), the decrease in free energy at a given temperature is a function of (a) \(\ln C_{1}\) (b) \(\ln C_{2}\) (c) \(\ln C_{2} \cdot C_{1}\) (d) \(\ln C_{1} / C\)

The standard reduction potential values of three metallic cations, \(\mathrm{X}, \mathrm{Y}\) and \(Z\) are \(+0.52,-3.03\) and \(-1.18 \mathrm{~V}\), respectively. The order of reducing power of the corresponding metals is (a) \(\mathrm{Y}>\mathrm{Z}>\mathrm{X}\) (b) \(\mathrm{X}>\mathrm{Y}>\mathrm{Z}\) (c) \(\mathrm{Z}>\mathrm{Y}>\mathrm{X}\) (d) \(Z>X>Y\)

Select the correct option if it is known that \(K_{\text {sp }}(\mathrm{AgCl})>K_{\text {sp }}(\mathrm{AgBr})>K_{\mathrm{sp}}(\) AgI \()\)

A gas ' \(X\) ' at 1 atm is bubbled through a solution containing a mixture of \(1 \mathrm{M}\) \(-\mathrm{Y}^{-}\) and \(1 \mathrm{M}-\mathrm{Z}^{-}\) at \(25^{\circ} \mathrm{C}\). If the reduction potential of \(Z>Y>X\), then. (a) \(\mathrm{Y}\) will oxidize \(\mathrm{X}\) and \(\mathrm{not} \mathrm{Z}\) (b) \(\mathrm{Y}\) will oxidize \(\mathrm{Z}\) and \(\mathrm{not} \mathrm{X}\) (c) \(Y\) will oxidize both \(X\) and \(Z\) (d) \(\mathrm{Y}\) will reduce both \(\mathrm{X}\) and \(\mathrm{Z}\)

The EMF of a galvanic cell composed of two hydrogen electrodes is \(272 \mathrm{mV}\). What is the \(\mathrm{pH}\) of the solution in which the anode is immersed if the cathode is in contact with a solution of \(\mathrm{pH}=3\) ? (a) 3 (b) \(6.7\)

The decreasing order of standard electrode potential of \(\mathrm{Mg}, \mathrm{K}, \mathrm{Ba}\) and \(\mathrm{Ca}\), is (a) \(\mathrm{K}, \mathrm{Ca}, \mathrm{Ba}, \mathrm{Mg}\) (b) \(\mathrm{Ba}, \mathrm{Ca}, \mathrm{K}, \mathrm{Mg}\) (c) \(\mathrm{Ca}, \mathrm{Mg}, \mathrm{K}, \mathrm{Ba}\) (d) \(\mathrm{Mg}, \mathrm{Ca}, \mathrm{Ba}, \mathrm{K}\)

The EMF of the cell: \(\mathrm{Hg}(1) \mid \mathrm{Hg}_{2} \mathrm{Cl}_{2}(\mathrm{~s})\), \(\mathrm{KCl}\) sol. \((1.0 \mathrm{~N}) \mid\) Quinohydrone \(\mid \mathrm{Pt}\), is \(0.210 \mathrm{~V}\) at \(298 \mathrm{~K}\). What is the \(\mathrm{pH}\) of the quinohydrone solution, the potential of the normal calomel electrode is \(0.279 \mathrm{~V}\) and \(E^{\circ}\) for the quinohydrone electrode is \(0.699 \mathrm{~V}\), both at the same temperature. \([2.303 R T / F=0.06]\) (a) \(3.5\) (b) \(7.0\) (c) \(1.85\) (d) \(-3.5\)

A metal having negative reduction potential, when dipped in the solution of its own ions, has a tendency to (a) remain as metal atoms (b) become electrically positive (c) become electrically negative (d) be deposited from the solution

The calomel electrode is reversible with respect to (a) \(\mathrm{Hg}_{2}^{2+}\) (b) \(\mathrm{H}^{+}\) (c) \(\mathrm{Hg}^{2+}\) (d) \(\mathrm{Cl}\)

Which one of the following does not get oxidized by bromine water? (a) \(\mathrm{Fe}^{2+}\) to \(\mathrm{Fe}^{3+}\) (b) \(\mathrm{Cu}^{+}\) to \(\mathrm{Cu}^{2+}\) (c) \(\mathrm{Mn}^{2+}\) to \(\mathrm{MnO}_{4}^{-}\) (d) \(\mathrm{Sn}^{2+}\) to \(\mathrm{Sn}^{4+}\)

What is the equilibrium constant of the reaction: \(2 \mathrm{Fe}^{3+}+\mathrm{Au}^{+} \rightarrow 2 \mathrm{Fe}^{2+}+\mathrm{Au}^{3+} ?\) Given \(E_{\mathrm{Au}^{+} \mid \mathrm{Au}}^{\circ}=1.68 \mathrm{~V}, E_{\mathrm{Au}^{3 \cdot} \mid \mathrm{Au}}^{\circ}=1.50 \mathrm{~V}\), \(E_{\mathrm{Fe}^{3 *} \mid \mathrm{Fe}^{\mathrm{e}}^{\circ}}=0.75 \mathrm{~V}\) and \(2.303 R T / F=0.06\) (a) \(1 \times 10^{22}\) (b) \(1 \times 10^{-22}\) (c) \(1 \times 10^{-11}\) (d) \(1 \times 10^{-72}\)

What is the EMF of the cell: \(\mathrm{Pt}, \mathrm{H}_{2}\) \((1 \mathrm{~atm}) \mid \mathrm{CH}_{2} \mathrm{COOH}(0.1 \mathrm{M}) \|(0.01\) M) \(\mathrm{NH}_{4} \mathrm{OH} \mid \mathrm{H}_{2}(1\) atm \()\), Pt? Given: \(K_{\mathrm{a}}\) for \(\mathrm{CH}_{3} \mathrm{COOH}=1.8 \times 10^{-5}, K_{\mathrm{b}}\) for \(\mathrm{NH}_{4} \mathrm{OH}=1.8 \times 10^{-5}, 2.303 R T / F=0.06\) \(\log 1.8=0.25\) ) (a) \(0.465 \mathrm{~V}\) (b) \(-0.465 \mathrm{~V}\) (c) \(-0.2325 \mathrm{~V}\) (d) \(-0.93 \mathrm{~V}\)

By how much would the oxidizing power of \(\mathrm{MnO}_{4}^{-} / \mathrm{Mn}^{2+}\) couple change if the \(\mathrm{H}^{\circ}\) ions concentration is decreased 100 times at \(25^{\circ} \mathrm{C}\) ? (a) increases by \(189 \mathrm{mV}\) (b) decreases by \(189 \mathrm{mV}\) (c) will increase by \(19 \mathrm{mV}\) (d) will decrease by \(19 \mathrm{mV}\)

The EMF of cell: \(\mathrm{H}_{2}(\mathrm{~g}) \mid\) Buffer \(\|\) Normal calomel electrode, is \(0.70 \mathrm{~V}\) at \(25^{\circ} \mathrm{C}\), when barometric pressure is \(760 \mathrm{~mm}\). What is the \(\mathrm{pH}\) of the buffer solution? \(E^{\circ}\). calomel \(=0.28 \mathrm{~V} .[2.303 R T / F=0.06]\) (a) \(3.5\) (b) \(7.0\) (c) tending to zero (d) tending to \(14.0\)

What is the solubility product of saturated solution of \(\mathrm{Ag}_{2} \mathrm{CrO}_{4}\) in water at \(298 \mathrm{~K}\) if the EMF of the cell: Ag | Ag' (satd. \(\left.\mathrm{Ag}_{2} \mathrm{CrO}_{4}\right) \| \mathrm{Ag}^{+}(0.1 \mathrm{M}) \mid \mathrm{Ag}\) is \(0.162\) \(\mathrm{V}\) at \(298 \mathrm{~K} ?[2.303 R T / F=0.06, \log 2=0.3]\) (a) \(2.0 \times 10^{-4}\) (b) \(3.2 \times 10^{-11}\)

A Tl'|Tlcouple was prepared by saturating \(0.10 \mathrm{M}-\mathrm{KBr}\) with TIBr and allowing \(\mathrm{Tl}^{+}\) ions form the insoluble bromide to equilibrate. This couple was observed to have a potential \(-0.444 \mathrm{~V}\) with respect to \(\mathrm{Pb}^{2+} \mid \mathrm{Pb}\) couple in which \(\mathrm{Pb}^{2+}\) was \(0.10 \mathrm{M} .\) What is the \(K_{\mathrm{sp}}\) of TIBr. [Given: \(E_{\mathrm{Pb}^{2+} \mid \mathrm{Pb}}^{\circ}=-0.126 \mathrm{~V}, E_{\mathrm{T}^{+} \mid \mathrm{T}}^{o}=-0.336 \mathrm{~V}\) \(\log 2.5=0.4,2.303 R T / F=0.06]\) (a) \(4.0 \times 10^{-6}\) (b) \(2.5 \times 10^{-4}\) (c) \(4.0 \times 10^{-5}\) (d) \(6.3 \times 10^{-3}\)

The electrode potential of hydrogen electrode in neutral solution and \(298 \mathrm{~K}\) is (a) \(-0.413 \mathrm{~V}\) (b) zero (c) \(-0.826 \mathrm{~V}\) (d) \(+0.413 \mathrm{~V}\)

The EMFs of the cell obtained by combining separately \(\underline{\mathrm{Zn}}\) and \(\overline{\mathrm{Cu}}\) electrodes of a Daniel cell with normal calomel electrodes are \(1.083 \mathrm{~V}\) and \(-0.018 \mathrm{~V}\), respectively, at \(25^{\circ} \mathrm{C}\). If the potential of normal calomel electrode is \(-0.28 \mathrm{~V}\), the EMF of the Daniel cell is (a) \(1.065 \mathrm{~V}\) (b) \(1.101 \mathrm{~V}\) (c) \(0.803 \mathrm{~V}\) (d) \(0.262 \mathrm{~V}\)

Electrode potential will be more for hydrogen electrode at \(\mathrm{pH}\) (at the same temperature) (a) 4 (b) 3 (c) 2 (d) 5

Saturated solution of \(\mathrm{KNO}_{3}\) is used to make 'salt bridge' because (a) velocity of \(\mathrm{K}^{+}\) is greater than that of \(\mathrm{NO}_{3}^{-}\) (b) velocity of \(\mathrm{NO}_{3}^{-}\) is greater than that of \(\mathrm{K}^{+}\) (c) velocities of both \(\mathrm{K}^{+}\) and \(\mathrm{NO}_{3}^{-}\) are nearly the same (d) \(\mathrm{KNO}_{3}\) is highly soluble in water

The voltage of the cell given below is \(-0.61 \mathrm{~V}\) \(\mathrm{Pt}\left|\mathrm{H}_{2}(1 \mathrm{bar})\right| \mathrm{NaHSO}_{3}(0.4 \mathrm{M}), \mathrm{Na}_{2} \mathrm{SO}_{3}\) \(\left(6.4 \times 10^{-2} \mathrm{M}\right) \| \mathrm{Zn}^{2+}(0.4 \mathrm{M}) \mid \mathrm{Zn}\) If \(E_{\mathrm{Zn}^{2+}}^{\circ}=-0.76 \mathrm{~V}\), Calculate \(K_{a 2}\) of \(\mathrm{H}_{2} \mathrm{SO}_{4} \cdot(2.303 R T / F=0.06)\) (a) \(3.2 \times 10^{-4}\) (b) \(3.2 \times 10^{-2}\) (c) \(3.2 \times 10^{-3}\) (d) \(6.4 \times 10^{-7}\)

The standard reduction potentials at \(25^{\circ} \mathrm{C}\) of \(\mathrm{Li}^{+}\left|\mathrm{Li}, \mathrm{Ba}^{2+}\right| \mathrm{Ba}, \mathrm{Na}^{+} \mid \mathrm{Na}\) and \(\mathrm{Mg}^{2+} \mid \mathrm{Mg}\) are \(-3.05,-2.73,-2.71\) and \(-2.37 \mathrm{~V}\), respectively. Which is the strongest reducing agent? (a) \(\mathrm{Li}\) (b) \(\mathrm{Ba}\) (c) \(\mathrm{Na}\) (d) \(\mathrm{Mg}\)

The dissociation constant for \(\mathrm{CH}_{3} \mathrm{COOH}\) is \(1.8 \times 10^{-5}\) at \(298 \mathrm{~K}\). The electrode potential for the half-cell: \(\mathrm{Pt} / \mathrm{H}_{2}\) \((1\) bar \() \mid 0.5 \mathrm{M}-\mathrm{CH}_{3} \mathrm{COOH}\), at \(298 \mathrm{~K}\) is \((\log 2=0.3 ; \log 3=0.48 ; 2.303 R T / F\) \(=0.06\) ) (a) \(-0.3024 \mathrm{~V}\) (b) \(-0.1512 \mathrm{~V}\) (c) \(+0.3024 \mathrm{~V}\) (d) \(+0.1512 \mathrm{~V}\)

The following reactions represent the reduction of \(\mathrm{IO}_{3}^{-}\) ion into \(\mathrm{I}^{-}\) ion in acidic and basic medium. Predict in which medium \(\mathrm{IO}_{3}^{-}\) ion will act as a better oxidizing agent? \(\mathrm{IO}_{3}^{-}+6 \mathrm{H}^{+}+6 \mathrm{e}^{-} \rightarrow \mathrm{I}^{-}+3 \mathrm{H}_{2} \mathrm{O}\) \(E^{\circ}=+0.907 \mathrm{~V}\) \(\mathrm{IO}_{3}^{-}+3 \mathrm{H}_{2} \mathrm{O}+6 \mathrm{e}^{-} \rightarrow \mathrm{I}^{-}+6 \mathrm{OH}^{-}\) \(E^{\circ}=+0.260 \mathrm{~V}\) (a) Acid medium (b) Basic medium (c) Equally in both (d) Not predictable

In an experimental set-up for the measurement of EMF of a half-cell using a reference electrode and a salt bridge, when the salt bridge is removed, the voltage (a) remains the same (b) increases to maximum (c) decreases half the value (d) drops to zero

When metallic copper is shaken with a solution of a copper salt, the reaction \(\mathrm{Cu}+\mathrm{Cu}^{2+} \rightleftharpoons 2 \mathrm{Cu}^{+}\) proceeds. When equilibrium is established at \(298 \mathrm{~K}\), \(\left[\mathrm{Cu}^{2+}\right] /\left[\mathrm{Cu}^{+}\right]^{2}=1.667 \times 10^{6} \mathrm{M}^{-1}\). If the standard potential of the \(\mathrm{Cu}^{2+} \mid \mathrm{Cu}\) halfcell is \(+0.3376 \mathrm{~V}\), what is the standard potential of Cu'| Cu half-cell? (Given: \(2.303 R T / F=0.06, \log 2=0.3, \log 3=0.48\) ) (a) \(-0.3732 \mathrm{~V}\) (b) \(0.6752 \mathrm{~V}\) (c) \(0.5242 \mathrm{~V}\) (d) \(0.151 \mathrm{~V}\)

After some time, the voltage of an electrochemical cell becomes zero. This is because (a) their electrode potential becomes zero. (b) their reduction potential become equal but have opposite sign. (c) their reduction potential become equal and have the same sign. (d) the ions of the electrolyte in the salt bridge stop moving.

Zinc granules are added in excess to a \(500 \mathrm{ml}\) of \(1.0 \mathrm{M}\) nickel nitrate solution at \(25^{\circ} \mathrm{C}\) until the equilibrium is reached. If the standard reduction potential of \(\mathrm{Zn}^{2+} \mid \mathrm{Zn}\) and \(\mathrm{Ni}^{2+} \mid \mathrm{Ni}\) are \(-0.75 \mathrm{~V}\) and \(-0.24 \mathrm{~V}\), respectively, the concentration of \(\mathrm{Ni}^{2+}\) in solution at equilibrium is \((2.303 R T / F=0.06)\) (a) \(1.0 \times 10^{-17} \mathrm{M}\) (b) \(1.0 \times 10^{17} \mathrm{M}\) (c) \(5 \times 10^{-17} \mathrm{M}\) (d) \(2 \times 10^{-17} \mathrm{M}\)

The EMF for the cell: \(\mathrm{Ag}(\mathrm{s}) \mid \mathrm{AgCl}(\mathrm{s})\) \(\mathrm{KCl}(0.2 \mathrm{M}) \| \mathrm{KBr}(0.001 \mathrm{M}) \mid \mathrm{AgBr}(\mathrm{s})\) \(\mathrm{Ag}(\mathrm{s})\) at \(25^{\circ} \mathrm{C}\) is \(\left(K_{\mathrm{sp}}(\mathrm{AgCl})=2.0 \times 10^{-10}\right.\) \(K_{\mathrm{sp}}(\mathrm{AgBr})=4.0 \times 10^{-13}, 2.303 R T / F=0.06\) \(\log 2=0.3\) ) (a) \(0.024 \mathrm{~V}\) (b) \(-0.024 \mathrm{~V}\) (c) \(-0.24 \mathrm{~V}\) (d) \(-0.012 \mathrm{~V}\)

Which one of the following statements is incorrect regarding an electrochemical cell? (a) The electrode on which oxidation takes place is called anode. (b) Anode is the negative pole. (c) The direction of the current is same as that of the direction of flow of electrons. (d) The flow of current is partly due to flow of electrons and partly due to flow of ions.

Identification of anode and cathode in an electrochemical cell is made by the use of (a) Galvanometer (b) Salt bridge (c) Voltmeter (d) Potentiometer

For the cell \(\mathrm{Zn}\left|\mathrm{Zn}^{2+} \| \mathrm{Cu}^{2+}\right| \mathrm{Cu}\), if the concentration of both, \(\mathrm{Zn}^{2+}\) and \(\mathrm{Cu}^{2+}\) ions are doubled, the EMF of the cell (a) doubles (b) reduces to half (c) remains same (d) becomes zero

The standard EMF of a galvanic cell can be calculated from (a) the size of the electrode (b) the \(\mathrm{pH}\) of the solution (c) the amount of metal in the anode (d) the \(E^{\circ}\) values of the half-cells

A volume of \(100 \mathrm{~m}\) of a buffer of \(1 \mathrm{M}\) \(-\mathrm{NH}_{3}\) and \(1 \mathrm{M}-\mathrm{NH}_{4}^{+}\) is placed in two half-cells connected by a salt bridge. \(A\) current of \(1.5 \mathrm{~A}\) is passed through the cell for \(20 \mathrm{~min}\). If electrolysis of water takes place only and the electrode reactions are: Right: \(2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}+4 \mathrm{e} \rightarrow 4 \mathrm{OH}^{-}\) and Left: \(2 \mathrm{H}_{2} \mathrm{O} \rightarrow 4 \mathrm{H}^{+}+\mathrm{O}_{2}+4 \mathrm{e}\), then, the \(\mathrm{pH}\) of the (a) right electrode will increase (b) left electrode will increase (c) both electrode will increase (d) both electrode will decrease

The value of equilibrium constant for a feasible cell reaction must be (a) \(\leq 1\) (b) Zero \((\mathrm{c})=1\) (d) \(>1\)

Use of lithium metal as an electrode in high energy density batteries is due to (a) lithium is the lightest element. (b) lithium has the highest oxidation potential. (c) lithium is quite reactive. (d) lithium does not corrode readily.

Which is correct about fuel cells? (a) Cell continuously run as long as fuels are supplied. (b) These are more efficient and free from pollution. (c) These are used to provide power and drinking water to astronauts in space programme. (d) All of these

Which of the following substances: Na, \(\mathrm{Hg}, \mathrm{S}, \mathrm{Pt}\) and graphite can be used as electrodes in electrolytic cells having aqueous solution? (a) \(\mathrm{Na}\), \(\mathrm{Pt}\) and graphite (b) \(\mathrm{Na}\) and \(\mathrm{Hg}\) (c) \(\mathrm{Hg}\), \(\mathrm{Pt}\) and graphite (d) \(\mathrm{Na}\) and \(\mathrm{S}\)

When a lead storage battery is discharged (a) \(\mathrm{SO}_{2}\) is evolved (b) lead sulphate is consumed (c) lead is formed (d) sulphuric acid is consumed

For a cell reaction involving a twoelectron change, the standard EMF of the cell is found to be \(0.295 \mathrm{~V}\) at \(25^{\circ} \mathrm{C}\). The equilibrium constant of the reaction at \(25^{\circ} \mathrm{C}\) will be (a) \(1 \times 10^{10}\) (b) \(1 \times 10^{-10}\) (c) \(29.5 \times 10^{-2}\) (d) \(2 \times 10^{10}\)

The \(E_{\text {Cell }}\) for \(\mathrm{Ag}(\mathrm{s}) \mid\) AgI (satd) \(\| \mathrm{Ag}^{+}\) \((0.10 \mathrm{M}) \mid \mathrm{Ag}(\mathrm{s})\) is \(+0.413 \mathrm{~V}\). What is the value of \(K_{s p}\) of \(\mathrm{Ag}\) I? (a) \(1.0 \times 10^{-8}\) (b) \(1.0 \times 10^{-7}\) (c) \(1.0 \times 10^{-14}\) (d) \(1.0 \times 10^{-16}\)

The preparation of \(\mathrm{LiOH}\) by the electrolysis of a \(35 \%\) solution of \(\mathrm{LiCl}\) using a platinum anode led to a current efficiency of \(80 \%\). What weight of \(\mathrm{LiOH}\) was formed by the passage of \(2.5 \mathrm{~A}\) for \(4825 \mathrm{~s} ?\) (a) \(1.92 \mathrm{~g}\) (b) \(2.40 \mathrm{~g}\) (c) \(0.96 \mathrm{~g}\) (d) \(0.672 \mathrm{~g}\)

Assuming that hydrogen behaves as an ideal gas, what is the EMF of the cell at \(25^{\circ} \mathrm{C}\) if \(P_{1}=600 \mathrm{~mm}\) and \(P_{2}=420 \mathrm{~mm}\) : \(\mathrm{Pt}\left|\mathrm{H}_{2}\left(P_{1}\right)\right| \mathrm{HCl}\left|\mathrm{H}_{2}\left(P_{2}\right)\right| \mathrm{Pt} ?\) [Given: \(2.303 R T / F=0.06, \log 7=0.85]\) (a) \(-0.0045 \mathrm{~V}\) (b) \(-0.0 \mathrm{~V}\) (c) \(+0.0045 \mathrm{~V}\) (d) \(+0.0015 \mathrm{~V}\)

Electrolysis of an acetate solution produces ethane according to the reaction: $$ 2 \mathrm{CH}_{3} \mathrm{COO}^{-} \rightarrow \mathrm{C}_{2} \mathrm{H}_{6}(\mathrm{~g})+2 \mathrm{CO}_{2}(\mathrm{~g})+2 \mathrm{e}^{-} $$ What total volume of ethane and \(\mathrm{CO}_{2}\) would be produced at \(0^{\circ} \mathrm{C}\) and \(1 \mathrm{~atm}\), if a current of \(0.5 \mathrm{~A}\) is passed through the solution for \(482.5\) min? Assume current efficiency \(80 \%\). (a) \(1.344 \mathrm{~L}\) (b) \(2.688 \mathrm{~L}\) (c) \(4.032 \mathrm{~L}\) (d) \(1.792 \mathrm{~L}\)

To perform an analysis of a mixture of metal ions by electro-deposition, the second metal to be deposited must not being plating out until the concentration ratio of the second to the first is about \(10^{6}\). What must be the minimum difference in standard potential of the two metals which form dipositive ions in order for such an analysis to be feasible? (a) \(0.177 \mathrm{~V}\) (b) \(0.354 \mathrm{~V}\) (c) \(0.708 \mathrm{~V}\) (d) \(0.088 \mathrm{~V}\)