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Consider the given data:
(a) \( \mathrm{HCl(g)} + 10 \, \mathrm{H_2O(l)} \rightarrow \mathrm{HCl} \cdot 10 \, \mathrm{H_2O} \, ; \, \Delta H = -69.01 \, \mathrm{kJ} \, mol^{-1} \)
(b) \( \mathrm{HCl(g)} + 40 \, \mathrm{H_2O(l)} \rightarrow \mathrm{HCl} \cdot 40 \, \mathrm{H_2O} \, ; \, \Delta H = -72.79 \, \mathrm{kJ} \, mol^{-1} \)
Choose the correct statement:

The formation enthalpies, $\Delta\text{H}_\text{f}^\ominus$ for $\text{H(g)}$ and $\text{O(g)}$ are $220.0$ and $250.0\text{ kJ mol}^{-1}$, respectively, at $298.15\text{ K}$, and $\Delta\text{H}_\text{f}^\ominus$ for $\text{H}_2\text{O(g)}$ is $-242.0\text{ kJ mol}^{-1}$ at the same temperature. The average bond enthalpy of the $\text{O}-\text{H}$ bond in water at $298.15\text{ K}$ is $\underline{\qquad}\text{ kJ mol}^{-1}$. (Nearest integer)

Given:
$\Delta\text{H}^\ominus_{\text{sub}[\text{C(graphite)}]} = 710\text{ kJ mol}^{-1}$
$\Delta_{\text{C}-\text{H}}\text{H}^\ominus = 414\text{ kJ mol}^{-1}$
$\Delta_{\text{H}-\text{H}}\text{H}^\ominus = 436\text{ kJ mol}^{-1}$
$\Delta_{\text{C}=\text{C}}\text{H}^\ominus = 611\text{ kJ mol}^{-1}$The$\Delta\text{H}_{\text{f}}^\ominus$ for $\text{CH}_2 = \text{CH}_2$ is ________ $\text{kJ mol}^{-1}$. (Nearest integer value)

The bond dissociation enthalpy of \( X_2 \) \( \Delta H^\circ_{\text{bond}} \) calculated from the given data is ________ \( \text{kJ mol}^{-1} \). (Nearest integer)
\( \mathrm{M^+X^- (s) \rightarrow M^+ (g) + X^- (g)} \) \( \Delta H^\circ_{\text{lattice}} = 800 \, \text{kJ mol}^{-1} \)
\( \mathrm{M (s) \rightarrow M (g)} \) \( \Delta H^\circ_{\text{sub}} = 100 \, \text{kJ mol}^{-1} \)
\( \mathrm{M (g) \rightarrow M^+ (g) + e^-}(g) \) \( \Delta H^\circ_{i} = 500 \, \text{kJ mol}^{-1} \)
\( \mathrm{X (g) + e^- (g) \rightarrow X^- (g)} \) \( \Delta H^\circ_{\text{eg}} = -300 \, \text{kJ mol}^{-1} \)
\( \mathrm{M (s) + \tfrac{1}{2} X_2 (g) \rightarrow M^+X^- (s)} \) \( \Delta H^\circ_{f} = -400 \, \text{kJ mol}^{-1} \)
[Given: \( \mathrm{M^+X^-} \) is a pure ionic compound and \( X \) forms a diatomic molecule \( X_2 \) in gaseous state]

Resonance in $\text{X}_2\text{Y}$ can be represented as

The enthalpy of formation of $\text{X}_2\text{Y} \left( \text{X}\equiv\text{X (g)} + \frac{1}{2}\text{Y}=\text{Y (g)} \rightarrow \text{X}_2\text{Y (g)} \right)$ is $80 \text{ kJ mol}^{-1}$. The magnitude of resonance energy of $\text{X}_2\text{Y}$ is _______ $\text{kJ mol}^{-1}$.(Nearest integer value)

[Given : Bond energy of $\text{X}\equiv\text{X}$, $\text{X}=\text{X}$, $\text{Y}=\text{Y}$ and $\text{X}=\text{Y}$ are $940$, $410$, $500$ and $602 \text{ kJ mol}^{-1}$ respectively. Valence X : 3, Y : 2]

Total enthalpy change for freezing of \( 1 \) mol of water at \( 10^\circ \mathrm{C} \) to ice at \( -10^\circ \mathrm{C} \) is __________ . (Given: \( \Delta_{\mathrm{fus}}H = x \, \mathrm{kJ/mol} \) ) . \( C_p[\mathrm{H_2O(l)}] = y \, \mathrm{j\,mol^{-1}\,K^{-1}} \) , \( C_p[\mathrm{H_2O(s)}] = z \, \mathrm{j\,mol^{-1}\,K^{-1}} \)

If \( \mathrm{C(diamond)} \rightarrow \mathrm{C(graphite)} + X \, \text{kJ mol}^{-1} \)
\( \mathrm{C(diamond)} + \mathrm{O}_2(g) \rightarrow \mathrm{CO}_2(g) + Y \, \text{kJ mol}^{-1} \)
\( \mathrm{C(graphite)} + \mathrm{O}_2(g) \rightarrow \mathrm{CO}_2(g) + Z \, \text{kJ mol}^{-1} \)
At constant temperature. Then

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the Reaction is spontaneous at boiling point of water. Choose the correct option.

The correct statement amongst the following is:

Let us consider a reversible reaction at temperature \( T \). In this reaction, both \( \Delta H \) and \( \Delta S \) were observed to have positive values. If the equilibrium temperature is \( T_e \), then the reaction becomes spontaneous at:

A sample of n-octane \( (1.14 \, \text{g}) \) was completely burnt in excess of oxygen in a bomb calorimeter, whose heat capacity is \( 5 \, \text{kJ} \, \text{K}^{-1} \). As a result of combustion reaction, the temperature of the calorimeter is increased by \( 5 \, \text{K} \). The magnitude of the heat of combustion of octane at constant volume is __________ \( \text{kJ} \, \text{mol}^{-1} \) (nearest integer).

Which of the following mixing of \( 1 \, \text{M} \) base and \( 1 \, \text{M} \) acid leads to the largest increase in temperature ?

Consider the following cases of standard enthalpy of reaction \( \left(\Delta H_x^{\,\circ} \text{ in kJ mol}^{-1}\right) \)
\( \mathrm{C_2H_6(g)} + \tfrac{7}{2}\,\mathrm{O_2(g)} \rightarrow 2\mathrm{CO_2(g)} + 3\mathrm{H_2O(l)} \quad \Delta H_1^{\,\circ} = -1550 \)
\( \mathrm{C(graphite)} + \mathrm{O_2(g)} \rightarrow \mathrm{CO_2(g)} \quad \Delta H_2^{\,\circ} = -393.5 \)
\( \mathrm{H_2(g)} + \tfrac{1}{2}\,\mathrm{O_2(g)} \rightarrow \mathrm{H_2O(l)} \quad \Delta H_3^{\,\circ} = -286 \)
The magnitude of \( \Delta H_{f \, \text{C}_2\text{H}_6(g)}^{\circ} \) \( \_\_\_\_\_\_\_\_\_\_ \) \( \mathrm{kJ\,mol^{-1}} \) \( \text{(Nearest integer)} \).

Standard entropies of \( \mathrm{X_2} \), \( \mathrm{Y_2} \) and \( \mathrm{XY_5} \) are \( 70 \), \( 50 \) and \( 110 \; \mathrm{J\,K^{-1}\,mol^{-1}} \) respectively. The temperature in Kelvin at which the reaction
$\frac{1}{2}\text{X}_2 + \frac{5}{2}\text{Y}_2 \rightleftharpoons \text{XY}_5 \quad \Delta\text{H}^\ominus = -35 \text{ kJ mol}^{-1}$

will be at equilibrium is __________ (Nearest integer)

\( \mathrm{S(g)} + \frac{3}{2}\mathrm{O_2(g)} \rightarrow \mathrm{SO_3(g)} + 2x \,\text{kcal} \)
\( \mathrm{SO_2(g)} + \frac{1}{2}\mathrm{O_2(g)} \rightarrow \mathrm{SO_3(g)} + y \,\text{kcal} \)
The heat of formation of \( \mathrm{SO_2(g)} \) is given by:

The hydration energies of \(K^+\) and \(Cl^-\) are \(-x\) and \(-y\) \(\text{kJ/mol}\) respectively. If lattice energy of KCl is \(-z\) \(\text{kJ/mol}\) then the heat of solution of KCl is:

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JEE Main 2025 24th Jan Evening Shift

Which of the following mixing of \( 1 \, \text{M} \) base and \( 1 \, \text{M} \) acid leads to the largest increase in temperature ?