For the process $H_2O_{(l)} \rightarrow H_2O_{(g)}$ at $100^{\circ}C$ and $1 \ atm$ pressure,which of the following is true?

$\Delta H_f^o$ of water is $-285.5\, kJ\, mol^{-1}$. If enthalpy of neutralisation of monoacidic strong base is $-57.3\, kJ\, mol^{-1}$,$\Delta H_f^o$ of $OH^{-}$ ion will be $.....\, kJ\, mol^{-1}$.

How many quantities have a similar unit as molar entropy?
$(i)$ Heat capacity
$(ii)$ Molar heat capacity
$(iii)$ Universal gas constant
$(iv)$ Specific heat capacity

The enthalpy of vaporization of a liquid at $500 \, K$ and $1 \, atm$ pressure is $10 \, kcal \, mol^{-1}$. The change in internal energy $(\Delta U)$ for $3 \, moles$ of the liquid at the same temperature and pressure is ............ $kcal$.

Calculate the enthalpy change on freezing of $1.0 \ mol$ of water at $10.0^{\circ} C$ to ice at $-10.0^{\circ} C$. Given: $\Delta_{fus} H = 6.03 \ kJ \ mol^{-1}$ at $0^{\circ} C$,$C_p [H_2 O_{(l)}] = 75.3 \ J \ mol^{-1} \ K^{-1}$,$C_p [H_2 O_{(s)}] = 36.8 \ J \ mol^{-1} \ K^{-1}$.

Heat of combustion of $CH_4, C_2H_4$ and $C_2H_6$ are $-890, -1411$ and $-1560 \ kJ/mol$ respectively. Which has the lowest calorific value?