$4.0 \, L$ of an ideal gas is allowed to expand isothermally into vacuum until the total volume is $20 \, L$. The amount of heat absorbed in this expansion is $..... \, L \, atm$.

Find the approximate value of $(\Delta H - \Delta U)$ in $J \cdot mol^{-1}$,for the formation of $CO$ from its elements at $298 \ K$. $(R = 8.314 \ J \cdot K^{-1} \ mol^{-1})$

In an isobaric process,the ratio of heat supplied to the system $(dQ)$ and work done by the system $(dW)$ for a diatomic gas is:

In an isochoric process,the increase in internal energy is

Which of the following is the correct option for the free expansion of an ideal gas under adiabatic conditions?

Express the change in internal energy of a system when
$(i)$ No heat is absorbed by the system from the surroundings,but work $(w)$ is done on the system. What type of wall does the system have?
$(ii)$ No work is done on the system,but $q$ amount of heat is taken out from the system and given to the surroundings. What type of wall does the system have?
$(iii)$ $w$ amount of work is done by the system and $q$ amount of heat is supplied to the system. What type of system would it be?