For the reaction $2H_{(g)} \to H_{2(g)}$,the signs of $\Delta H$ and $\Delta S$ are:

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 irreversible expansion of an ideal gas under isothermal condition,the correct option is :

$C_{(s)} + 2 H_{2(g)} \rightarrow CH_{4(g)}$; $\Delta H = -74.8 \ kJ \ mol^{-1}$
Which of the following diagrams gives an accurate representation of the above reaction?
[$R \rightarrow$ reactants; $P \rightarrow$ products]

At $25$ $^\circ C$ and $1$ $atm$ pressure,the enthalpies of formation of $C_2H_4(g)$,$CO_2(g)$,and $H_2O(l)$ are $52$,$-394$,and $-286 \, kJ \, mol^{-1}$ respectively. The enthalpy of combustion of $C_2H_4$ is ....... $kJ \, mol^{-1}$.

$\Delta H$ and $\Delta E$ for the reaction,$Fe_{2}O_{3(s)} + 3H_{2(g)} \rightarrow 2Fe_{(s)} + 3H_{2}O_{(l)}$ at constant temperature are related as