Work done by an ideal gas at a constant volume is

For the following reaction,the relation between $\Delta H$ and $\Delta U$ is:
$2 SO_{2(g)} + O_{2(g)} \rightarrow 2 SO_{3(g)}$

Identify the state functions and path functions out of the following: enthalpy,entropy,heat,temperature,work,free energy.

One mole of an ideal gas at $25\,^{\circ}C$ expands its volume from $1\,L$ to $4\,L$ at constant temperature. What work (in $J$) is done if the gas expands against a vacuum $(P_{ext} = 0)$?

Internal energy is

Which of the following is an extensive property?