Question

on heating blue coloured powder copper nitrate in a boiling test tube copper oxide oxygen gas and a brown gas x is formed

Answer 1

(ii) The brown gas X is nitrogen dioxide, NO2. (1/2)
(iii) Thermal decomposition. (1/2)
(iv) pH< 7
Reason : NO2 dissolves in water to form acidic solution (pH range below 7)

Answer 2

on heating blue coloured powder copper nitrate in a boiling test tube copper oxide oxygen gas and a brown gas x is formed