List of top Chemistry Questions on Thermochemistry asked in JEE Main

If the enthalpy of sublimation of Li is \(155\,\text{kJ mol}^{-1}\), enthalpy of dissociation of \( \mathrm{F_2} \) is \(150\,\text{kJ mol}^{-1}\), ionization enthalpy of Li is \(520\,\text{kJ mol}^{-1}\), electron gain enthalpy of F is \(-313\,\text{kJ mol}^{-1}\), and standard enthalpy of formation of LiF is \(-594\,\text{kJ mol}^{-1}\), then the magnitude of lattice enthalpy of LiF is ____________ kJ mol\(^{-1}\) (Nearest integer).

Consider the following data :
\( \Delta_f H^\ominus (\text{methane, g}) = -X \text{ kJ} mol^{-1} \)
Enthalpy of sublimation of graphite \( = Y \text{ kJ mol}^{-1} \)
Dissociation enthalpy of \( H_2 = Z \text{ kJ mol}^{-1} \)
The bond enthalpy of C-H bond is given by :}

Total enthalpy change for freezing of 1 mol water at 10°C to ice at -10°C is ______ (Given: $ \Delta_{\text{fus}}H = x \, \text{kJ/mol} $, $ C_p[\text{H}_2\text{O}(l)] = y \, \text{J mol}^{-1} \text{K}^{-1} $, and $ C_p[\text{H}_2\text{O}(s)] = z \, \text{J mol}^{-1} \text{K}^{-1} $)

Consider the following data: - Heat of formation of \( CO_2(g) \) = -393.5 kJ mol\(^{-1}\) - Heat of formation of \( H_2O(l) \) = -286.0 kJ mol\(^{-1}\) - Heat of combustion of benzene = -3267.0 kJ mol\(^{-1}\) The heat of formation of benzene is ________________________ kJ mol\(^{-1}\) (Nearest integer).

Solid fuel used in rocket is a mixture of Fe₂O₃ and Al (in ratio 1 : 2) the heat evolved (KJ) per gram of the mixture is ______ (Nearest integer)
Given \(\Delta H_f^{\circ}(Al_2O_3) = -1700 \, \text{KJ mol}^{-1}\)
\(\Delta H_f^{\circ}(Fe_2O_3) = -840 \, \text{KJ mol}^{-1}\) }