JAMB - Chemistry (1979 - No. 14)
When ammonium, potassium and calcium carbonates are each separately heated
none of them will decompose
each of them will decompose to give carbondioxide and the respective oxide
ammonium carbonate and potassium carbonate will not decompose
only ammonium carbonate and the respective oxide
ammonium carbonate will decompose to give carbondioxide, water and ammonia
Explication
Solid ammonium carbonate decomposes as it is heated.
(NH4)2CO3 → 2 NH3 + CO2 + H2O