What is calorimetry?

Assume each reaction is carried out in an open container. For which reaction will $\Delta H = \Delta E$ ?

Enthalpy $(H)$ is equal to

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?

Identify the pair in which both are not extensive properties.

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 $kJ$)