For the following combustion reaction occurring in an automobile: $2C_{8}H_{18(g)} + 25O_{2(g)} \to 16CO_{2(g)} + 18H_{2}O_{(g)}$,what are the signs of $\Delta H$,$\Delta S$,and $\Delta G$?

For the reaction $\frac{1}{2}X_2 + \frac{3}{2}Y_2 \to XY_3$,$\Delta H = -30 \ kJ/mol$. Given $\Delta S_{X_2} = 60 \ J/mol \cdot K$,$\Delta S_{Y_2} = 40 \ J/mol \cdot K$,and $\Delta S_{XY_3} = 50 \ J/mol \cdot K$,calculate the temperature at equilibrium in $K$.

In a reversible process,under what condition does the heat exchanged become a state function?

Reversible expansion of an ideal gas under isothermal and adiabatic conditions are as shown in the figure.
$AB \to$ Isothermal expansion
$AC \to$ Adiabatic expansion
Which of the following options is not correct?

The ${\Delta _c}{U^\circ}$ of combustion of $CH_{4(g)}$ at a certain temperature is $-100 \ kJ/mol$. The value of ${\Delta _c}{H^\circ}$ is

For a hypothetical reaction $A_{2(g)} + B_{2(g)} \rightleftharpoons 2AB_{(g)}$,at $200 \ K$,$\Delta_r G$ and $\Delta_r S$ are $20 \ kJ \ mol^{-1}$ and $-20 \ J \ K^{-1} \ mol^{-1}$ respectively. If $\Delta_r C_p = 20 \ J \ K^{-1} \ mol^{-1}$,find $\Delta_r H$ at $400 \ K$ in $kJ \ mol^{-1}$.