One mole of an ideal gas is allowed to expand freely and adiabatically into vacuum until its volume has doubled. Which of the following statements is $NOT$ true concerning this expansion?

The heats of combustion $\Delta H$ of $CH_4$,$C_2H_6$,$C_2H_4$,and $C_2H_2$ gases are $-212.8$,$-373.0$,$-337.0$,and $-310.5 \ kcal$ respectively at the same temperature. Which of these gases is the best fuel?

Enthalpy of formation of $CO_{2(g)}$,$H_2O_{(l)}$ and $C_6H_{12}O_{6(s)}$ are $-393$,$-286$ and $-1170 \ kJ \ mol^{-1}$ respectively. The quantity of heat liberated when $18 \ g$ of $C_6H_{12}O_{6(s)}$ is burnt completely in oxygen is (in $kJ$)

One mole of an ideal monoatomic gas at temperature $T$ expands adiabatically in an insulated flask from $1 \ L$ to $2 \ L$ against an external pressure of $1 \ atm$. What is the final temperature?

The molar heat capacity $(C_p)$ of $CD_2O$ is $10 \, cal \, K^{-1} \, mol^{-1}$ at $1000 \, K$. The change in entropy associated with cooling of $32 \, g$ of $CD_2O$ vapour from $1000 \, K$ to $100 \, K$ at constant pressure will be.....$cal \, deg^{-1}$ ($D = $ deuterium,atomic mass $= 2 \, u$)

An ideal gas in a thermally insulated vessel at internal pressure $P_1$,volume $V_1$,and absolute temperature $T_1$ expands irreversibly as shown in the following diagram. The final pressure,volume,and absolute temperature of the gas are $P_2$,$V_2$,and $T_2$ respectively. Which is the correct statement for the expansion?