Question

The electrolysis of an aqueous solution of Na2SO4 using graphite electrodes will cause the formation at the anode of:
a) sodium b) hydrogen
c) chlorine d) oxygen gas
Write the equation that take place at the cathode.

Which of the following species is oxidized during the operation the electrochemical cell Mg/Mg2+ // Cu2+/Cu.
(a) Which metal is the anode and which is the cathode?
(b) Write the equation at the cathode and the anode.

Answer 1

$(1)$ At anode oxygen gas will be formed

So, option (d) oxygen gas is correct

Equation at cathode-

$2H^++\ 2e^-\to H_2(g)$

$(2)$ Specie which is oxidized during the operation of electrochemical cell is-

$$Mg$$

(a)

Mg act as anode and Cu act as cathode

(b)

Equations-

At cathode-

$$Cu^{2+}(aq)+2e^-\to Cu(s)$$

At anode-

$$Mg(s)\to Mg^{2+}+2e^-$$