Question

(a) Select the correct answer

The aqueous solution of the compound which contains both ions and molecules is

A. $H_{2}S{O}_4$

B. $HCl$

C. $HN{O}_3$

D. $C{H}_{3}COOH$

(b) Correct the following statement ___.

Lead bromide conducts electricity.

(c) A metal article is to be electroplated with silver. The electrolyte selected is sodium argentocyanide

(i) What kind of salt sodium argentocyanide ?

(ii) Why is it preferred to silver nitrate as an electrolyte ?

(iii) State one condition to ensure that the deposit is smooth, firm and long lasting.

(iv) Write the reaction taking place at the cathode.

(v) Write the reaction taking place at the anode.

(d) Aqueous solution of nickel sulphate contains $N{i}^{2+}$ and $S{O}_4^{2-}$ ions.

(i) Which ion moves towards the cathode ?

(ii) What is the product at the anode ?

Answer 1

(a) D. CH3COOH

Reason: It is a weak acid, it does not dissociate 100% completely.

(b) Molten Lead bromide conducts electricity.

Because the molten state has charged particle ions.

(c)

i) A complex salt

ii) When silver nitrate is used, deposition of silver on the cathode is not uniform because it is a strong
electrolyte.

iii) A small current is passed for a longer time.

iv) Reduction reaction: $A{g}^{+}+1e^{-}\to Ag$

v) Oxidation reaction: $Ag\to A{g}^{+}+1e^{-}$

(d)
i) $N{i}^{2+}ions$.

ii) Oxygen gas when the inert electrode is used.