What is calorimetry?

For a change in state of $1 \, \text{mole}$ of a non-ideal gas,the change in internal energy is $\Delta U = 30.0 \, \text{L} \cdot \text{atm}$. The state changes from $(2.0 \, \text{atm}, 3.0 \, \text{L}, 95 \, \text{K})$ to $(4.0 \, \text{atm}, 5.0 \, \text{L}, 245 \, \text{K})$. What is the change in enthalpy $(\Delta H)$ in $\text{L} \cdot \text{atm}$?

An ideal gas is allowed to expand against a constant pressure of $2 \ bar$ from $10 \ L$ to $50 \ L$ in one step. Calculate the amount of work done by the gas. If the same expansion were carried out reversibly,will the work done be higher or lower than the earlier case? (Given that $1 \ L \ bar = 100 \ J$)

Which of the following statements is not correct?

In an exothermic reaction,the reactants:

Identify the type of system if boiling water is kept in a half-filled closed vessel.