WAEC - Chemistry (2012 - No. 29)
On heating, the following trioxocarbonate (IV) salts decompose to give solid residue except
ammonium trioxocarbonate (IV)
calcium trioxocarbonate (IV)
lead (ll) trioxocarbonate(IV)
zinc trioxocarbonate (IV)
Explanation
Ammonium trioxocarbonate (IV) is an unstable compound. It decomposes on heating to yield ammonia, carbon (IV) oxide and water. All of these are gases.