The enthalpies of combustion of cyclohexane $(C_6H_{12})$, cyclohexene $(C_6H_{10})$ and $H_2$ are $-3920 \text{ kJ mol}^{-1}$, $-3800 \text{ kJ mol}^{-1}$ and $-241 \text{ kJ mol}^{-1}$ respectively. The enthalpy of hydrogenation of cyclohexene is

Consider the reaction at $300 \ K$: $H_{2(g)} + Cl_{2(g)} \to 2HCl_{(g)}$; $\Delta H^o = -185 \ kJ$. If $2 \ mole$ of $H_2$ completely react with $2 \ mole$ of $Cl_2$ to form $HCl$,what is $\Delta U^o$ for this reaction in $kJ$?

Three moles of an ideal gas are expanded isothermally from a volume of $300 \ cm^3$ to $2.5 \ L$ at $300 \ K$ against a constant external pressure of $1.9 \ atm$. The work done in joules is:

One mole of an ideal monoatomic gas is heated in a process $PV^{5/2} = \text{constant}$. The amount of heat absorbed in the process for a $36 \ ^\circ C$ rise in temperature is (in $cal$):

The molar heats of fusion and vaporisation of benzene are $10.9$ and $31.0 \ kJ \ mol^{-1}$ respectively. The changes in entropy for the solid $\rightarrow$ liquid and liquid $\rightarrow$ vapour transitions for benzene are $x$ and $y \ JK^{-1} \ mol^{-1}$,respectively. The value of $(y-x)$ (in $JK^{-1} \ mol^{-1}$) is (At $1 \ atm$,benzene melts at $5.5^{\circ} C$ and boils at $80^{\circ} C$).

$X \, g$ of ethanol $(CH_3CHO)$ is burnt in a bomb calorimeter and $Y \, J$ of heat is produced. Then,which of the following is correct for the enthalpy of combustion?