Give reasons for the following — pertaining to the above laboratory preparation of nitric acid

(i) concentrated hydrochloric acid is not used as a reactant in the laboratory preparation.

(ii) the complete apparatus in the laboratory preparation does not contain parts made of rubber or cork.

(iii) the reaction temperature is maintained below 200°C

(iv) at high temperatures the sodium sulphate or potassium sulphate formed, forms a crust and sticks to the glass apparatus.

State the colour of :

(i) pure nitric acid

(ii) nitric acid obtained in the laboratory

(iii) nitric acid obtained in the laboratory after passage of air or addition of water to it.

Convert ammonia to nitric acid by Ostwald's process giving all conditions.

State how —

(i) a higher ratio of the reactant air

(ii) exothermicity of the catalytic reaction

(iii) use of low temp. in the conversion of NO to NO₂ — affects each related step in Ostwald's process.