Question

what gas is given out at cathode and anode ? how do you test these gases ?

Answer 1

Answer:

chlorine gas is liberated at the anode.

Answer 2

At cathode, H

2

is evolved and at anode O

2

is evolved.

At cathode, H

+

ion takes two electron to convert itself into H

2

gas. 2 moles of H

+

gives 1 mole of H

2

.

2H

+

(aq)+2e

−

→H

2

(g)

At anode, OH

−

ion releases two electrons to convert into water and O

2

. 2 mole OH

−

gives 0.5 mole O

2

, i.e why volume of one gas collected at one electron is double of another.