Give four different word equations relating to acidic properties of an aq. soln. of HCl gas.

Give balanced equations to obtain

(i) H₂

(ii) CO₂

(iii) SO₂

(iv) H₂S

from dil. HCl.

State how you would prove that HCl contains :

(i) hydrogen – using an active metal below magnesium

(ii) chlorine – using an oxidising agent not containing lead.

State the composition of aqua regia. State which component is the oxidising agent in aqua regia.