For the reaction $C(s) + O_2(g) \rightarrow CO_2(g)$,the enthalpy change $(\Delta H)$ is:

The heat evolved in the combustion of benzene is given by the equation $C_6H_{6(l)} + 7.5 O_{2(g)} \to 3H_2O_{(l)} + 6CO_{2(g)}$,$\Delta H = -781.0 \ kcal \ mol^{-1}$. Which of the following quantities of heat energy will be evolved when $39 \ g$ of benzene is burnt in an open container?

When the aqueous solution of $0.5 \, mole$ of $HNO_3$ is mixed with $0.3 \, mole$ of $OH^{-}$ solution,what will be the liberated heat in $kJ$? (Enthalpy of neutralization is $= 57.1 \, kJ \, mol^{-1}$)

Calculate the standard enthalpy change of the reaction: $C_2H_{2(g)} + \frac{5}{2}O_{2(g)} \rightarrow 2CO_{2(g)} + H_2O_{(\ell)}$ given the following standard enthalpies of formation:
$\Delta_fH^{\circ}(CO_2) = -393 \ kJ \ mol^{-1}$
$\Delta_fH^{\circ}(H_2O) = -286 \ kJ \ mol^{-1}$
$\Delta_fH^{\circ}(C_2H_2) = 227 \ kJ \ mol^{-1}$

The enthalpy of neutralisation of $NH_4OH$ with $HCl$ is $-51.46 \ kJ \ mol^{-1}$ and the enthalpy of neutralisation of $NaOH$ with $HCl$ is $-55.90 \ kJ \ mol^{-1}$. The enthalpy of ionisation of $NH_4OH$ is $...... \ kJ \ mol^{-1}$

The bond dissociation energies of $XY$,$X_2$,and $Y_2$ (all diatomic molecules) are in the ratio $1 : 1 : 0.5$. If the enthalpy of formation of $XY$ is $\Delta_fH = -200 \ kJ \ mol^{-1}$,find the bond dissociation energy of $X_2$ in $kJ \ mol^{-1}$.