Calculate the change in internal energy of the system if $20 \ kJ$ work is done on the system and it releases $10 \ kJ$ heat in a particular reaction. (in $kJ$)

In a cylinder,$1.0 \, \text{kcal}$ of heat is added to $1.2 \, \text{L}$ of $O_2$ gas at a constant pressure of $1 \, \text{atm}$. The volume changes to $1.5 \, \text{L}$. Calculate the change in internal energy $(\Delta U)$ for this process. (in $, \text{kcal}$)

In an isothermal expansion,the increase in volume with a decrease in pressure of a gas is greater than in an adiabatic expansion,because .............

Calculate the change in internal energy $(\Delta U)$ if an ideal gas expands from $0.5 \text{ dm}^3$ to $3.5 \text{ dm}^3$ at a constant pressure of $2 \text{ bar}$ by absorbing $1800 \text{ J}$ of heat energy. (in $\text{ J}$)

Three moles of an ideal gas expand reversibly under isothermal conditions from $2 \, L$ to $20 \, L$ at $300 \, K$. The amount of heat change (in $kJ / mol$) in the process is:

Given below are two statements.
Statement-$I$ : Adiabatic work done is positive when work is done on the system and internal energy of the system increases.
Statement-$II$ : No work is done during free expansion of an ideal gas.
In the light of the above statements,choose the correct answer from the options given below.