JEE Main 2013 — Thermodynamics (C) Question with Solution
JEE Main 2013 (25 Apr Online)
Question
Given that:
(i) of is
(ii) Bond energies of and are and respectively,
The resonance energy of is :
Choose an option
Show full solutionCorrect option: A
Correct answer
A
Step-by-step explanation
$\begin{aligned} \Delta \mathrm{H}_{\mathrm{f}}{ }^{\mathrm{o}}= & {[\text { Energy required for breaking of bonds }] } \\ & -[\text { Energy released for forming of bonds }] \\ = & \left(\Delta \mathrm{H}_{\mathrm{N} \equiv \mathrm{N}}+\frac{1}{2} \Delta \mathrm{H}_{\mathrm{O}=\mathrm{O}}-\left(\Delta \mathrm{H}_{\mathrm{N}=\mathrm{N}}+\Delta \mathrm{H}_{\mathrm{N}=\mathrm{O}}\right)\right. \\ = & \left(946+\frac{1}{2} \times 498\right)-(418+607)=170 \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \text { Resonance energy }=170-82=88 \mathrm{~kJ} \mathrm{~mol}^{-1} \end{aligned}$
Practice this on the real CBT interface
Solve this JEE Main question (and the rest of the Thermodynamics (C) chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.
Solve interactively →About this question
This is a previous-year question from JEE Main 2013, covering the Thermodynamics (C) chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.