Question

Neither q nor W is a state function but q + W is state function. Explain why??

Answer 1

Q and W both depend on the path so neither of them is a state function. Here U is internal energy of the system which is a state function. ... It takes energy to break the bonds between the molecules or ions of the solute.

 q + w = ΔU. As ΔU is a state function, hence q + w is a state function.  

On dissolution, entropy increases i.e., ΔS is +ve. If TΔS > ΔH,  

then ΔG will be –ve. Hence, the process is spontaneous.