The number of endothermic process/es from the following is:
$A. I_{2(g)} \rightarrow 2I_{(g)}$
$B. HCl_{(g)} \rightarrow H_{(g)} + Cl_{(g)}$
$C. H_2O_{(l)} \rightarrow H_2O_{(g)}$
$D. C_{(s)} + O_{2(g)} \rightarrow CO_{2(g)}$
$E. \text{Dissolution of ammonium chloride in water}$

Which of the following endothermic processes are spontaneous?

The heat of combustion of $CO$ at $290 \ K$ and constant volume is $-280.5 \ kJ$. What will be the heat of combustion at constant pressure in $kJ$?

The standard molar enthalpies of formation for ethane,$CO_2$,and water $(l)$ are $-21.1$,$-94.1$,and $-68.3 \text{ kcal/mol}$ respectively. What is the standard molar enthalpy of combustion for ethane in $\text{kcal/mol}$?

$A$ fish swimming in a water body,when taken out,is covered with a film of water of weight $36 \ g$. When it is subjected to cooking at $100^{\circ} C$,the internal energy change for vaporization in $kJ \ mol^{-1}$ is $......$ [nearest integer].
[Assume steam to be an ideal gas. Given $\Delta_{vap} H^{\ominus}$ for water at $373 \ K$ and $1 \ bar$ is $41.1 \ kJ \ mol^{-1}$; $R = 8.31 \ J \ K^{-1} \ mol^{-1}$]

Calculate $\Delta H^{\circ}$ for the reaction, $Na_2O_{(s)} + SO_{3(g)} \longrightarrow Na_2SO_{4(s)}$, given the following reactions:
$(A) \ Na_{(s)} + H_2O_{(l)} \longrightarrow NaOH_{(s)} + \frac{1}{2}H_{2(g)} \quad \Delta H^{\circ} = -146 \ kJ$
$(B) \ Na_2SO_{4(s)} + H_2O_{(l)} \longrightarrow 2NaOH_{(s)} + SO_{3(g)} \quad \Delta H^{\circ} = +418 \ kJ$
$(C) \ 2Na_2O_{(s)} + 2H_{2(g)} \longrightarrow 4Na_{(s)} + 2H_2O_{(l)} \quad \Delta H^{\circ} = +259 \ kJ$