The heat evolved during the combination of $24 \, g$ of $C$ and $128 \, g$ of $S$ according to the reaction $C + 2S \to CS_2$ with $\Delta H = 22.0 \, kcal$ is:

If a refrigerator's door is opened in a closed room,then we get:

Considering the reaction $C_{(s)} + O_{2(g)} \longrightarrow CO_{2(g)} + 393.5 \ kJ$,the signs of $\Delta H, \Delta S$,and $\Delta G$ respectively are:

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?

The standard molar heat of formation of ethane,$CO_2$,and water $(l)$ are respectively $-21.1$,$-94.1$,and $-68.3 \ kcal$. The standard molar heat of combustion of ethane will be $kcal$.

The process of evaporation of a liquid is completed by .......