$1.8 \ g$ of water is vaporized by supplying $4 \ kJ$ of heat at $100^{\circ}C$. What is the molar heat of vaporization of water at the same temperature?

The difference between the reaction enthalpy change $(\Delta _r H)$ and reaction internal energy change $(\Delta _r U)$ for the reaction $2C_6H_{6(l)} + 15O_{2(g)} \longrightarrow 12CO_{2(g)} + 6H_2O_{(l)}$ at $300 \ K$ is $....$ $J \ mol^{-1}$ $(R = 8.314 \ J \ mol^{-1} \ K^{-1})$

Given the following thermochemical equations:
$(i) S_{(s)} + \frac{3}{2} O_{2(g)} \rightarrow SO_{3(g)} + 2x \, kcal$
$(ii) SO_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow SO_{3(g)} + y \, kcal$
Find the heat of formation of $SO_{2(g)}$.

Products are favoured in a chemical reaction taking place at a constant temperature and pressure. Consider the following statements: $(i)$ The change in Gibbs energy for the reaction is negative. $(ii)$ The total change in Gibbs energy for the reaction and the surroundings is negative. $(iii)$ The change in entropy for the reaction is positive. $(iv)$ The total change in entropy for the reaction and the surroundings is positive. The statements which are always true are:

For the complete combustion of ethene,$C_2H_{4(g)} + 3O_{2(g)} \rightarrow 2CO_{2(g)} + 2H_2O_{(l)}$,the amount of heat produced as measured in a bomb calorimeter is $1406 \ kJ \ mol^{-1}$ at $300 \ K$. The minimum value of $T \Delta S$ needed to reach equilibrium is $(-)....... \ kJ$. (Nearest integer) Given: $R = 8.3 \ J \ K^{-1} \ mol^{-1}$

The heats of combustion of $C_2H_4, C_2H_6$ and $H_2$ are $-1409.5 \, kJ, -1558.3 \, kJ$ and $-285.6 \, kJ$ respectively. The heat of hydrogenation of ethene is ...... $kJ$.