Which of the following are extensive properties?

For which of the following reactions is $\Delta U = \Delta H$?

Find the constant external pressure required to expand a gas from $2.5 \ L$ to $4.5 \ L$ if the amount of work done is $500 \ J$ at $298 \ K$. (in $bar$)

Identify the pair in which both are not extensive properties.

The enthalpy of fusion of ice per mole is approximately $...$ $kJ / mol$.

Which of the following is not an extensive property?