Which of the following is not a thermodynamic state function?

$A$ unit mass of a liquid with volume $V_1$ is completely changed into a gas of volume $V_2$ at a constant external pressure $P$ and temperature $T$. If the latent heat of evaporation for the given mass is $L$,then the increase in the internal energy of the system is:

The volume of one mole of the gas is changed from $V$ to $2V$ at constant pressure $p$. If $\gamma$ is the ratio of specific heats of the gas,what is the change in internal energy of the gas?

Write and explain the first law of thermodynamics.

$A$ system is taken from state $A$ to state $B$ along two different paths. The heat absorbed and work done by the system along these two paths are $Q_1, Q_2$ and $W_1, W_2$ respectively,then

When $1500 \ J$ of heat is supplied to a gas at a constant pressure of $2.5 \times 10^{5} \ N/m^{2}$,the volume increases by $2.5 \times 10^{-3} \ m^{3}$. The increase in the internal energy of the gas is ..... $J$?