Write equations for the reactions :

(i) dil. HCl and sodium thiosulphate.

(ii) dil. HCl and lead nitrate soln.

Write a balanced equation for each of the following :

(i) Red lead is warmed with concentrated hydrochloric acid.

(ii) Magnesium metal is treated with dilute hydrochloric acid.

What property of hydrogen chloride is demonstrated when it is collected by downward delivery [upward displacement]. Why is hydrogen chloride not collected over water.

Match each substance A to E listed below with the appropriate description given below :

[A] Sulphur
[B] Silver chloride
[C] Hydrogen chloride
[D] Copper [II] Sulphate
[E] Graphite.

(i) A covalent compound which behaves like an ionic compound in aqueous solution.
(ii) A compound which is insoluble in cold water but soluble in excess of ammonia solution.