Question

(a) Select the correct answer.

A compound which during electrolysis in its molten state, liberates a reddish brown gas at the anode.

(i) Sodium chloride

(ii) Copper [II] oxide

(iii) Copper [II] sulphate

(iv) Lead [II] bromide

(b) During electroplating of an article with nickel,

(i) Name

A. The electrolyte

B. The cathode

C. The anode

(ii) Give the reaction of the electrolysis at

A. The cathode

B. The anode

(c) A, B and C are three electrolytic cells, connected in different circuits. Cell 'A' contains NaCl soln., and the bulb in the circuit glow brightly, when the circuit is completed. Cell 'B' contains acetic acid and the bulb does not glow. Give reason for each observation.

Answer 1

(a) Lead [II] bromide
(b) (i)
(A) Electrolyte: $NiC{l}_2$
(B) Anode: Ni plate
(C) Cathode: Article to be electroplated

(ii) anode

$Ni⟶N{i}^{2+}+2e^{-}$

Cathode

$N{i}^{2+}+2e^{-}⟶Ni$

(c)

A is a sodium chloride solution which is a strong electrolyte which contains only ions. So more electricity is conducted and the bulb glows brightly.

B is an acetic acid which contains both ions and molecules that are less number of ions. So less electricity is conducted and the bulb glows dimly.

C is a sugar solution which is a non-electrolyte that is it does not contain ions so electricity is not conducted and the bulb does not glow.