Acidic - Ammonium chloride
Basic - Sodium carbonate
Neutral - Potassium sulphate
(b)
Plaster of Paris, or calcium sulphate hemi hydrate (CaSO4.1/2H2O) [X], is a white compound that sets into a hard mass in about half an hour after wetting with water. This property of plaster of Paris is used in making casts for broken limbs in hospitals.
Plaster of Paris on mixing with water changes to gypsum [Y] once again giving a hard solid mass. Following is the chemical equation for the reaction
CaSO4.1/2H2O + 11/2H2O → CaSO4.2H2O
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