Which of the following is an extensive property of a system?

Which from the following defines enthalpy of a system?

In thermodynamics,which one of the following is not an intensive property?

The enthalpy change $(\Delta H)$ for the reaction,$N_{2(g)} + 3H_{2(g)} \to 2NH_{3(g)}$ is $-92.38 \ kJ$ at $298 \ K$. The internal energy change $\Delta U$ at $298 \ K$ is .............. $kJ$

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

Calculate work done in isothermal reversible expansion of $1 \ mol$ of an ideal gas from an initial pressure of $10 \ bar$ to a final pressure of $1 \ bar$ at $300 \ K$ $\left(R = 8.314 \ J \ K^{-1} \ mol^{-1}\right)$. (in $kJ$)