The correct formula of calomel is:

Which relation is correct for $\Lambda^0_{m(H_2O)}$?

At $298 \ K$,the standard electrode potentials of $Cu^{2+}/Cu$,$Zn^{2+}/Zn$,$Fe^{2+}/Fe$ and $Ag^{+}/Ag$ are $0.34 \ V$,$-0.76 \ V$,$-0.44 \ V$ and $0.80 \ V$,respectively. On the basis of standard electrode potential,predict which of the following reactions cannot occur?

What is the reaction when a $Zn$ rod is kept in a copper nitrate solution?

Whose oxidation and reduction is carried out in a hydrogen-oxygen fuel cell?

Give the uses of the mercury cell.