Arrange the ions `Ag^(+), Zn^(2+), H^(+) and Na^(+)` in order of their increasing tendency to get liberated at cathode.
`["Given: "E_(Ag^(+)|Ag)^(@)=0.80V, E_(Zn^(2+)|Zn)^(@)=-0.76V,`
`E_(2H^(+)|H_(2))^(@)=0.00V, E_(Na^(+)|Na)^(@)=-2.17V]`

Explanation

The order of increasing standard electrode potential of the given ions :
`E_(Na^(+)|Na)^(@)ltE_(Zn^(2+)|Zn)^(@)ltE_(2H^(+)|H_(2))^(@)ltE_(Ag^(+)|Ag)^(@)`.
Among the given electrodes `Na^(+)|Na and Ag^(+)|Ag` have lowest and highest reduction potential, respectively. Thus `Ag^(+)` has the highest tendency to get reduced whereas Na has the highest tendency to get oxidised. Thus the order of increasing tendencies to get liberated at cathode is :
`Na^(+)ltZn^(2+) lt H^(+) lt Ag^(+)`.