Chapter 8

A salt bridge contains : (a) A saturated solution of \(\mathrm{KCl}\) and agar-agar (b) A saturated solution of \(\mathrm{KNO}_{3}\) and agar-agar (c) A saturated solution of \(\mathrm{NH}_{4} \mathrm{NO}_{3}\) and agar-agar (d) All of these

The nature of curve of \(E_{\text {cell }}^{\circ}\) vs. \(\log K_{c}\) is : (a) straight line (b) parabola (c) hyperbola (d) elliptical curve

Consider the following equations for a cell reaction $$ \begin{gathered} A+B \rightleftharpoons C+D ; \quad E^{\circ}=x \text { volt, } K_{e q}=K_{1} \\\ 2 A+2 B \rightleftharpoons 2 C+2 D ; E^{\circ}=y \text { volt, } K_{e q}=K_{2} \end{gathered} $$ then : (a) \(x=y, K_{1}=K_{2}\) (b) \(x=2 y, K_{1}=2 K_{2}\) (c) \(x=y, K_{1}^{2}=K_{2}\) (d) \(x^{2}=y, K_{1}^{2}=K_{2}\)

Which graph correctly correlates \(E_{\text {cell }}\) as a function of concentrations for the cell $$ \mathrm{Zn}(s)+2 \mathrm{Ag}^{+}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+2 \mathrm{Ag}(s), \quad E_{\text {cell }}^{\circ}=1.56 \mathrm{~V} $$ \(Y\) -axis : \(E_{\text {cell }}, X\) -axis : \(\log _{10} \frac{\left[\mathrm{Zn}^{2+}\right]}{\left[\mathrm{Ag}^{+}\right]}\)

Which graph correctly correlates \(\dot{E}_{\text {cell }}\) as' a function of concentrations for the cell $$ \mathrm{Zn}(s)+2 \mathrm{Ag}^{+}(a q) \longrightarrow \mathrm{Zn}^{2+}(a q)+2 \mathrm{Ag}(s), \quad E_{\text {cell }}^{\circ}=1.56 \mathrm{~V} $$

The Nernst equation \(E=E^{\circ}-R T / n F \ln Q\) indicates that the \(Q\) will be equal to equilibrium constant \(K_{c}\) when : (a) \(E=E^{\circ}\) (b) \(R T / n F=1\) (c) \(E=\) zero (d) \(E^{\circ}=1\)

The cell reaction \(\mathrm{Hg}_{2} \mathrm{Cl}_{2}(s)+\mathrm{Cu}(s) \longrightarrow \mathrm{Cu}^{2+}(a q)+2 \mathrm{Cl}^{-}(a q)+2 \mathrm{Hg}(l)\), is best represented by : (a) \(\mathrm{Cu}(s)\left|\mathrm{Cu}^{+2}(a q) \| \mathrm{Hg}_{2} \mathrm{Cl}_{2}(s)\right| \mathrm{Hg}(l)\) (b) \(\mathrm{Cu}(s)\left|\mathrm{Cu}^{+2}(a q) \| \mathrm{Hg}(\mathrm{l})\right| \mathrm{HgCl}_{2}(s)\) (c) \(\mathrm{Cu}(s)\left|\mathrm{Cu}^{+2}(a q) \| \mathrm{Cl}^{-}(a q)\right| \mathrm{Hg}_{2} \mathrm{Cl}_{2}(s)|\operatorname{Hg}(l)| \operatorname{Pt}(s)\) (d) \(\mathrm{Hg}_{2} \mathrm{Cl}_{2}(s)\left|\mathrm{Cl}^{-}(a q) \| \mathrm{Cu}^{+2}(a q)\right| \mathrm{Cu}(s)\)

The cell reaction \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q)+14 \mathrm{H}^{+}(a q)+6 \mathrm{Fe}^{2+}(a q) \longrightarrow 6 \mathrm{Fe}^{3+}(a q)+2 \mathrm{Cr}^{3+}(a q)+7 \mathrm{H}_{2} \mathrm{O}(l)\) is best represented by : (a) \(\operatorname{Pt}(s)\left|\mathrm{Fe}^{+2}(a q), \mathrm{Fe}^{3+}(a q) \| \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q), \mathrm{Cr}^{3+}(a q)\right| \operatorname{Pt}(s)\) (b) \(\mathrm{Pt}(s)\left|\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q), \mathrm{Cr}^{+3}(a q) \| \mathrm{Fe}^{3+}(a q), \mathrm{Fe}^{+2}(a q)\right| \mathrm{Pt}(s)\) (c) \(\mathrm{Fe}^{2+}(a q)\left|\mathrm{Fe}^{3+}(a q) \| \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q)\right| \mathrm{Cr}^{3+}(a q)\) (d) \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(a q)\left|\mathrm{Cr}^{3+}(a q) \| \mathrm{Fe}^{3+}(a q)\right| \mathrm{Fe}^{2+}(a q)\)

Select the correct cell reaction of the cell \(\mathrm{Ag}(s)\left|\mathrm{Ag}^{+}(a q) \| \mathrm{Cu}^{2+}(a q)\right| \mathrm{Cu}(s)\) : (a) \(2 \mathrm{Ag}(s)+\mathrm{Cu}(s) \longrightarrow \mathrm{Cu}^{+2}(a q)+2 \mathrm{Ag}^{+}(a q)\) (b) \(\mathrm{Cu}(s)+2 \mathrm{Ag}^{+}(a q) \longrightarrow \mathrm{Cu}^{2+}(a q)+2 \mathrm{Ag}(s)\) (c) \(2 \mathrm{Ag}(s)+\mathrm{Cu}^{2+}(a q) \longrightarrow \mathrm{Cu}(s)+2 \mathrm{Ag}^{+}(a q)\) (d) \(\mathrm{Cu}^{2+}(a q)+2 \mathrm{Ag}^{+}(a q) \longrightarrow 2 \mathrm{Ag}(s)+\mathrm{Cu}(s)\)

Standard electrode potential of SHE at \(298 \mathrm{~K}\) is : (a) \(0.05 \mathrm{~V}\). (b) \(0.10 \mathrm{~V}\) (c) \(0.50 \mathrm{~V}\) (d) \(0.00 \mathrm{~V}\)