Question

1. What happens when nitrates of Ca, Zn, Pb, and Cu are heated?
2. Write their chemical equation.
3. Name the nitrate compound which is blue coloured.

Answer 1

(a) When nitrates of Calcium (Ca), Zinc (Zn), Lead (Pb), and Copper (Cu) are heated, they decompose to form their respective metal oxides, brown nitrogen dioxide (NO₂) gas, and oxygen (O₂) gas.

(b)

Calcium nitrate: \[\ce{2Ca(NO3)2 ->[\Delta] 2CaO + 4NO2 ^ + O2 ^}\]

Zinc nitrate: \[\ce{2Zn(NO3)2 ->[\Delta] 2ZnO + 4NO2 ^ + O2 ^}\]

Lead nitrate: \[\ce{2Pb(NO3)2 ->[\Delta] 2PbO + 4NO2 ^ + O2 ^}\]

Copper nitrate: \[\ce{2Cu(NO3)2 ->[\Delta] 2CuO + 4NO2 ^ + O2 ^}\]

(c) Copper nitrate [Cu(NO₃)₂] is the blue-coloured nitrate salt.