Equilibrium Constant from Nernst Equation

Q. $E^{\circ }$ for the cell is $Zn|Z{n}^{2+}\left(aq\right)||C{u}^{2+}\left(aq\right)|Cu$ at ${25}^{\circ }C$, the equilibrium constant for the reaction $Zn+C{u}^{2+}\left(aq\right)\rightleftharpoons Cu+Z{n}^{2+}\left(aq\right)$ is of the order of

1. 10^-37
2. 10^-28
3. 10⁺¹⁸
4. 10⁺¹⁷

Q. 100 mL of buffer of 1 M $N{H}_3\left(aq\right)$ and 1 M $N{H}_4^{\oplus }\left(aq\right)$ are placed in two compartments of a voltaic cell separately. A current of 1.5 A is passed through both cells for 20 min. If only electrolysis of water takes place, then:

1. pH of LHE half cell will increase
2. pH of RHE half cell will increase
3. pH of both half cell will increase
4. pH of both half cell will decrease

Q. If the $E_{cell}^o$ for a given reaction has a negative value, then which of the following gives the correct relationships for the values of $\Delta G^o$ and $K_{eq}$?

1. $△G^o<0;K_{eq}<1$
2. $△G^o<0;K_{eq}>1$
3. $△G^o>0;K_{eq}<1$
4. $△G^o>0;K_{eq}>1$