The heat of combustion $\left(kJ \ mol^{-1}\right)$ is highest for

For a dimerization reaction,$2 A_{(g)} \rightarrow A_{2(g)}$ at $298 \ K$,$\Delta U^{\ominus} = -20 \ kJ \ mol^{-1}$,$\Delta S^{\ominus} = -30 \ J \ K^{-1} \ mol^{-1}$,then the $\Delta G^{\ominus}$ will be........ $J$

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

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

Which graph represents an exothermic reaction?