On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed.
a. Write a balance chemical equation of the reaction.
b. Identify the brown gas X revolved.
c. Identify the type of reaction.
d. What could be the pH range of aqueous solution of the gas X?
a. 2Cu(NO3)2 (s) → 2CuO(s) + 4NO2(g) + O2(g)
On heating copper(II) nitrate powder, copper oxide, oxygen gas and nitrogen dioxide gas is evolved.
b. Brown gas X is nitrogen dioxide NO2.
c. It is a decomposition reaction as a single reactant splits on heating to form two or more products. Since heat is involved so we can also say it is a thermal decomposition reaction.
d. X is nitrogen dioxide which is a acidic gas so its aqueous solution will be acidic in nature and its pH would be less than 7. Since the acid pH varies between 0-7.
Nitrogen dioxide with water forms nitrous acid(HNO2)