1. An aqueous solution of (NH4) SC4 is acidic in nature.
2. (NH4)2SO4 is formed from weak base, NH4OH, and strong acid, H2SO4 .
In water, it dissociates completely
(NH4)2 SO4 (aq) → 2NH+4 (aq) + SO2-4 (aq)
NH+4 ions undergoes hydrolysis to form NH4OH and H+ ions.
NH4 +(aq) + H2O(l) ⇌ NH4OH(aq) + H+(aq)
NH4OH is a weak base and therefore remains almost unionised in solution. This results in increased H+ ion concentration in solution making the solution acidic.
