NH4Cl;PbSO4;NaHCO3; and Cu(NO4)2

Question

What would decompose on heating

Answer 1

NH4Cl and NaHCO3 would decompose on heating.

NH4Cl breaks down into NH3 gas and HCl gas upon heating:
NH4Cl -> NH3 + HCl

NaHCO3 breaks down into Na2CO3 (sodium carbonate), CO2 gas, and H2O upon heating:
2NaHCO3 -> Na2CO3 + CO2 + H2O

PbSO4 and Cu(NO4)2 would not decompose on heating.