Question

when 1 mole of anhydrous CU S o4 is dissolved in excess of water -66.4 kilo kilo joule heat is evolved when 1 mole of CUSO4.5H2O is dissolved in water the heat change is 11.7 kilojoule calculate enthalpy of hydration of CU S o4 anhydrous
{ANSWER WITH PROPER EXPLAINATION}​

Answer 1

When anhydrous CuSO4 is dissolved in excess of water then there is complete dissociation into respective ions and Cu2+ (aq) and (SO4) 2-(aq)

is formed

Here heat is evolved which consists of :- lattice energy + hydration enthalpy of Cu2+ (aq) and (SO4) 2-(aq)

When CuSO4. 5H20 is dissolved in water than actually being a coordinate compound and already being fully hydrated it does not get hydrated further

Here change in heat is due to lattice energy which remains same for anhydrous CuSO4 and CuSO4. 5H20 because cations and anions and ionic interactions between them is still the same even if CuSO4 is hydrated or is anhydrous

This is because in hydrated salts,

The water molecule is either attached to the salt through hydrogen bond or is involved in the complex formation by coordinate bonds or simply sitting in the voids

In CuSO4.5H20 one molecule of water is hydrogen bonded and 4 molecules are coordinate bonded

But