List of top Chemistry Questions on Enthalpy change asked in MHT CET

Calculate the standard enthalpy change for the following reaction,
\(2\text{C}_2\text{H}_6\text{(g)}+7\text{O}_2\text{(g)}⟶4\text{CO}_2\text{(g)}+6\text{H}_2\text{O}\text{(l)}\)
Given, \(\Delta _fH^{\circ}(\text{C}_2\text{H}_6) = -85 \text{kJ mol}^{-1}\)
\(\Delta _fH^{\circ}(\text{CO}_2) = -390 \text{kJ mol}^{-1}\)
\(\Delta _fH^{\circ}(\text{H}_2\text{O}) = -285 \text{kJ mol}^{-1}\)

Calculate \(\Delta \text{H}\) for the following reaction at \(300 \text{K}\)
\(2\text{C}_{(s)}+3\text{H}_{2(g)}⟶\text{C}_2\text{H}_{6(g)}\) if \(\Delta \text{U}\) for the reaction is \(-80 \text{kJ}\) (\(\text{R} = 8.314 \text{JK}^{-1}\text{mol}^{-1}\))

Calculate the standard enthalpy of combustion of carbon monoxide if
\(\Delta _fH^{\circ}(\text{CO}) = -110\text{ kJ mol}^{-1}\)
\(\Delta _fH^{\circ}(\text{CO}_2) = -393\text{ kJ mol}^{-1}\)

Which of the following equations is used to obtain enthalpy change of a reaction?

Calculate the enthalpy change when 6 g. \(\text{CO(g)}\) reacts with sufficient \(\text{NO}_2\text{(g)}\) according to the following reaction
\(4\,\text{CO(g)}+2\,\text{NO}_2\text{(g)}\rightarrow 4\,\text{CO}_2\text{(g)}+2\text{N}_2\text{(g)}\,; \Delta _rH^0 = -1200 \text{kJ}\)

In a particular reaction, 4 kJ heat is released by the system and 12 kJ work done on the system. Calculate the \(\Delta H\) and \(\Delta U\).

Which of the following relations is correct for a reaction \(\text{S}_{(s)}+\text{O}_{2(g)}\rightarrow \text{SO}_{2(g)}\) ?

Find \(\Delta n\) when 1 mol of each \(\text{NH}_{3(g)}\) and \(\text{HCl}_{(g)}\), reacts to form solid \(\text{NH}_4\text{Cl}\).

\(\text{C}_2\text{H}_5\text{OH}(l)+3\text{O}_2(g)\rightarrow 2\text{CO}_2(g)+3\text{H}_2\text{O}(l)\)
The value of enthalpy change (\(\Delta H\)) for above reaction at \(27\,^{\circ}\text{C}\) is \(-1366.5\) kJ \(\text{mol}^{-1}\). Then value of internal energy change for the same reaction at this temperature will be

The bond dissociation enthalpy of \(\text{H}_2\), \(\text{Cl}_2\) and HCl are \(434\), \(242\) and \(431\) kJ \(\text{mol}^{-1}\) respectively. Calculate the enthalpy of formation of HCl.

The enthalpy change for the reaction \( \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \) is \( -92.4 \, \text{kJ/mol} \). What is the enthalpy change when 4 moles of nitrogen react?

The enthalpy of formation for \( \text{H}_2(g) \), \( \text{O}_2(g) \), and \( \text{H}_2O(l) \) are 0, 0, and -285.8 kJ/mol, respectively. What is the enthalpy change for the following reaction: \[ \text{2H}_2(g) + \text{O}_2(g) \rightarrow 2\text{H}_2O(l) \]