Chemistry · 2026
JEE Main · 21 January 2026, Shift 2 · Q54
Consider the following data: Δ_f H^ (methane, g )=- X kJ mol^-1 Enthalpy of sublimation of graphite = Y kJ mol^-1 Dissociation enthalpy of H_2= Z kJ…
Consider the following data :
$\displaystyle \Delta_f \mathrm{H}^{\ominus}$ (methane, g$\displaystyle )=-\mathrm{X} \mathrm{kJ} \mathrm{mol}^{-1}$
Enthalpy of sublimation of graphite $\displaystyle =\mathrm{Y} \mathrm{kJ} \mathrm{mol}^{-1}$
Dissociation enthalpy of $\displaystyle \mathrm{H}_2=\mathrm{Z} \mathrm{kJ} \mathrm{mol}^{-1}$
The bond enthalpy of $\displaystyle \mathrm{C}-\mathrm{H}$ bond is given by :
Official answer
From NTA’s final answer key for this paper.
(4)
$\displaystyle \frac{X+Y+2 Z}{4}$
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JEE Main 2026 Chemistry question, with the answer from NTA’s final answer key. Where our answers come from.