ΔG=ΔH−TΔS
For spontaneous,
ΔG<0
ΔH−TΔS<O
ΔS>TΔH
ΔS>450K30×103Jmol−1
ΔS>66.6Jmol−1K−1 (Check by options)
So, option (1) , i.e. 70 Jmol−1 K−1 satisfies it.
NEET UG 2020 — Chemistry Physical Chemistry
If for a certain reaction ΔrH is 30kJmol−1 at 450K, the value of ΔrS (in JK−1mol−1) for which the same reaction will be spontaneous at the same temperature is
Held on 30 Apr 2020 · Verified 9 Jul 2026.
70
−33
33
−70
Sign in to track your attempts and accuracy.
Sign in to keep a private note on this question. Nothing you write is ever public.
For the reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g), ΔH = -198 kJ. Which condition favours forward reaction?
The unit of rate constant for a first-order reaction is:
Among the following choose the ones with equal number of atoms. A. 212 g of $\mathrm{Na}_2 \mathrm{CO}_3(\mathrm{~s})$ [molar mass $=106 \mathrm{~g}$ ] B. 248 g of $\mathrm{Na}_2 \mathrm{O}$ (s) [molar mass $=62 \mathrm{~g}$ ] C. 240 g of $\mathrm{NaOH}(\mathrm{s})$ [molar mass $=40 \mathrm{~g}]$ D. 12 g of $\mathrm{H}_2(\mathrm{~g})$ [molar mass $=2 \mathrm{~g}$ ] E. 220 q of $\mathrm{CO}_2(\mathrm{q})$ [molar mass $\left.=44 \mathrm{~g}\right]$ Choose the correct answer from the options given below:
For the reaction $\mathrm{A}(\mathrm{g}) \rightleftharpoons 2 \mathrm{~B}(\mathrm{~g})$, the backward reaction rate constant is higher than the forward reaction rate constant by a factor of 2500 , at 1000 K . [Given : $\mathrm{R}=0.0831 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ ] $\mathrm{K}_{\mathrm{p}}$ for the reaction at 1000 K is
The standard heat of formation, in $\mathrm{kcal} / \mathrm{mol}^{\text {of }} \mathrm{Ba}^{2+}$ is : [Given : standard heat of formation of $\mathrm{SO}_4^{2-}$ ion (aq) $=-216 \mathrm{kcal} / \mathrm{mol}$, Standard heat of crystallisation of $\mathrm{BaSO}_4(\mathrm{~s})=-4.5 \mathrm{kcal} / \mathrm{mol}$, standard heat of formation of $\left.\mathrm{BaSO}_4(\mathrm{~s})=-349 \mathrm{kcal} / \mathrm{mol}\right]$
Work through every NEET UG Physical Chemistry PYQ, year by year.