Which of the following are extensive properties?

The heat of reaction at constant pressure is given by

An ideal gas at $300 \, K$ expands from a volume of $1 \times 10^{-3} \, m^3$ to $1 \times 10^{-2} \, m^3$ against a constant external pressure of $1 \times 10^5 \, N \, m^{-2}$. Calculate the work done.

What is the internal energy change when $2$ moles of an ideal gas at $25^{\circ} C$ is compressed isothermally and reversibly from $1.0 \ bar$ to $10.0 \ bar$?

Prove that the change in enthalpy of a system in which a chemical reaction occurs is equal to the heat gained by the system at constant pressure.

$A$ well-stoppered thermos flask contains some ice cubes. This is an example of a