Question

Give reasons.

(i) Neither q nor w is a state function but q+w is a state function.

(ii) The dissolution of Ammonium chloride in water is endothermic, but still it dissolves in water.

(iii) The entropy of steam is more than that of water at its boiling point.

Answer 1

Solution for your first query,

 

This is total energy called internal energy E = q+w. It is a state function as it depends on the intial and final state and independent of the path.

solution for 2nd query

At room temperature (T = 300K), dissolution of ammonium chloride is an endothermic process, because the solution feels colder as the solid NH4Cl dissolves in water and absorbs energy from water to do so. Therefore the enthalpy of dissolution is POSITIVE

solution for 3rd query

The entropy of steam is more than that of water at its boiling point. Explain. At the boiling point, both water and steam (water vapours) exist together and are in equilibrium. However, the entropy of steam is more because of greater randomness of the H2O molecules in the gaseous state than in the liquid state.

Answer 2

(1) Q is heat of the system while W is the work done or done by the system.

(2) Amonium chloride is dissolves in because Amonium in heat water cold so Amoniun chloride will disolve

I HOPE THE ANSWER CORRECT