Which of the following fuels will have the highest calorific value $(kJ/kg)$?

The heat of neutralization of which acid and base is close to $-13.6 \ kcal/mol$?

Identify the molecule for which the enthalpy of atomization $\left(\Delta_{a} H^{\ominus}\right)$ and bond dissociation enthalpy $\left(\Delta_{BOND} H^{\ominus}\right)$ are not equal.

$AB$,$A_2$,and $B_2$ are diatomic molecules. Enthalpies of dissociation of $AB$,$A_2$,and $B_2$ are in the ratio of $1:1:0.5$. Enthalpy of formation of $AB$,$\Delta_f H = -100 \ kJ \ mol^{-1}$. Find the dissociation enthalpy of $A_2$?
Reaction : $\frac{1}{2} A_2 + \frac{1}{2} B_2 \to AB$

The heat of combustion of $C_xH_y$,carbon,and hydrogen are $a, b$,and $c \ cal/mole$ respectively. The heat of formation of $C_xH_y$ will be:

The heats of formation of two compounds $X$ and $Y$ are $-84 \ kJ$ and $-156 \ kJ$ respectively. Which of the following statements is correct?