Which of the following is not thermodynamical function ?

Solution :
The thermodynamic state of a homogeneous system may be represented by certain specific thermodynamic variables such as pressure $$p,$$ volume $$V,$$ temperature $$T$$ and entropy $$S.$$ Out of these four variables, any two are independent and when they are known the others may be determined. Thus, there are only two independent variables and the others may be considered their functions. For complete knowledge of the system certain relations are required and for this purpose we introduce some functions of variables $$p,V,T$$  and $$S$$ known as thermodynamic functions. There are four principal thermodynamic functions
(i) Internal energy $$\left( U \right)$$
(ii) Helmholtz function$$\left( H \right)$$
(iii) Enthalpy $$\left( F \right)$$
(iv) Gibb’s energy $$\left( G \right)$$
Hence, work done is not thermodynamic function.