What are extensive properties?

Under which of the following conditions is the relation $\Delta H = \Delta E + P \Delta V$ valid for a closed system?

Which one among the following is the correct option for the relationship between $C_{P}$ and $C_{V}$ for one mole of an ideal gas?

For $1 \text{ mole}$ of an ideal gas expanding isothermally from $1 \text{ L}$ to $10 \text{ L}$ at $300 \text{ K}$,the value of $\Delta U$ is: $(R = 2 \text{ cal mol}^{-1} \text{ K}^{-1})$

When $2 \ L$ of an ideal gas expands isothermally into a vacuum to a total volume of $6 \ L$,what is the change in internal energy in $J$? (Nearest integer)

The internal energy change when a system goes from state $A$ to $B$ is $40 \, kJ/mol$. If the system goes from $A$ to $B$ by a reversible path and returns to state $A$ by an irreversible path,what would be the net change in internal energy?