Exothermic reactions occur in which of the following processes?

Explain the difference between the system and surroundings.

Predict the change in internal energy for an isolated system at constant volume.

Two mole of an ideal gas is expanded isothermally and reversibly from $1 \ L$ to $10 \ L$ at $300 \ K$. The enthalpy change (in $kJ$) for the process is .....$kJ$

Name the energy which arises due to the motion of atoms or molecules in a body. How is this energy affected when the temperature is increased?

If the work done by $2 \ mol$ of an ideal gas during isothermal reversible expansion from $5 \ L$ to $50 \ L$ is $-189.1 \ L \ atm$,the temperature of the gas (in $^{\circ}C$) is