Question

Predict whether the following reaction is feasible under standard conditions or not: 

\[\ce{Zn_{(s)} + Cu{^{2+}_{(aq)}} -> Zn{^{2+}_{(aq)}} + Cu_{(s)}}\]

Given that `E_(Zn^(2+)//Zn)^circ` = −0.76 volts and `E_(Cu^(2+)//Cu)^circ` = +0.34 volts.

Answer 1

Given: `E_(Zn^(2+)//Zn)^circ` = −0.76 volts

`E_(Cu^(2+)//Cu)^circ` = +0.34 volts

Anode: Zn is oxidised to Zn²⁺.

Cathode: Cu²⁺ is reduced to Cu.

We know that 

`E_"cell"^circ = E_"cathode"^circ - E_"anode"^circ`

`E_"cell"^circ` = (+0.34 V) − (−0.76 V)

`E_"cell"^circ` = +1.10 V

Since the standard potential is positive (`E_"cell"^circ` = +1.10 V), the reaction is feasible and will occur spontaneously under standard conditions.