Chemistry·MCQ Practice

Standard Enthalpy of Formation — MCQ Practice

NEET UG
Updated 13 Sep 2026

Interactive MCQ Practice

Test your knowledge. Click “Solve” to reveal options, select your answer, then check the result. 6 questions available.

Q1medium

Given the following standard enthalpies of formation: ΔHf∘(C2H5OH(l))=−277.7 kJ/mol\Delta H_f^\circ(\text{C}_2\text{H}_5\text{OH}(\text{l})) = -277.7\,\text{kJ/mol} ΔHf∘(CO2(g))=−393.5 kJ/mol\Delta H_f^\circ(\text{CO}_2(\text{g})) = -393.5\,\text{kJ/mol} ΔHf∘(H2O(l))=−285.8 kJ/mol\Delta H_f^\circ(\text{H}_2\text{O}(\text{l})) = -285.8\,\text{kJ/mol} Calculate the standard enthalpy of combustion for ethanol, C2H5OH(l)\text{C}_2\text{H}_5\text{OH}(\text{l}), according to the reaction: C2H5OH(l)+3O2(g)→2CO2(g)+3H2O(l)\text{C}_2\text{H}_5\text{OH}(\text{l}) + 3\text{O}_2(\text{g}) \rightarrow 2\text{CO}_2(\text{g}) + 3\text{H}_2\text{O}(\text{l})

Q2easy

Which of the following equations represents the standard enthalpy of formation of HCl(g)\text{HCl}(\text{g})?

Q3medium

The standard enthalpy of formation of NH3(g)\text{NH}_3(\text{g}) is −46.1 kJ/mol-46.1\,\text{kJ/mol}. What is the enthalpy change for the reaction: 2NH3(g)→N2(g)+3H2(g)2\text{NH}_3(\text{g}) \rightarrow \text{N}_2(\text{g}) + 3\text{H}_2(\text{g})?

Q4easy

Which of the following statements about standard enthalpy of formation is INCORRECT?

Q5hard

Given the following data: C(graphite)+O2(g)→CO2(g)\text{C}(\text{graphite}) + \text{O}_2(\text{g}) \rightarrow \text{CO}_2(\text{g}), ΔH∘=−393.5 kJ\Delta H^\circ = -393.5\,\text{kJ} H2(g)+12O2(g)→H2O(l)\text{H}_2(\text{g}) + \frac{1}{2}\text{O}_2(\text{g}) \rightarrow \text{H}_2\text{O}(\text{l}), ΔH∘=−285.8 kJ\Delta H^\circ = -285.8\,\text{kJ} C2H6(g)+72O2(g)→2CO2(g)+3H2O(l)\text{C}_2\text{H}_6(\text{g}) + \frac{7}{2}\text{O}_2(\text{g}) \rightarrow 2\text{CO}_2(\text{g}) + 3\text{H}_2\text{O}(\text{l}), ΔH∘=−1560 kJ\Delta H^\circ = -1560\,\text{kJ} Calculate the standard enthalpy of formation of ethane, C2H6(g)\text{C}_2\text{H}_6(\text{g}).

Q6medium

The standard enthalpy of formation of H2O(g)\text{H}_2\text{O}(\text{g}) is −241.8 kJ/mol-241.8\,\text{kJ/mol}, and the standard enthalpy of formation of H2O(l)\text{H}_2\text{O}(\text{l}) is −285.8 kJ/mol-285.8\,\text{kJ/mol}. What is the standard enthalpy of vaporization of water at 298 K298\,\text{K}?