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Chemistry · 2026 · 4 marks
NEET 2026 · 21 June · Code 50 · Q69
Consider the reversible processes for 1.0 mol of an ideal gas as shown in the figure. w 1, w 2, w 3 and w 4 represent work done (in calories) in the…
Consider the reversible processes for $\displaystyle 1.0$ mol of an ideal gas as shown in the figure.
$\displaystyle \mathrm{w}_1, \mathrm{w}_2, \mathrm{w}_3$ and $\displaystyle \mathrm{w}_4$ represent work done (in calories) in the processes $\displaystyle 1$, $\displaystyle 2$, $\displaystyle 3$ and $\displaystyle 4$, respectively; $\displaystyle \Delta \mathrm{U}_2$ and $\displaystyle \Delta \mathrm{U}_4$ are changes in the internal energy for the processes $\displaystyle 2$ and $\displaystyle 4$, respectively.
[use $\displaystyle \mathrm{R}=2$ cal $\displaystyle \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ ]
The correct option is
$\displaystyle \mathrm{w}_1, \mathrm{w}_2, \mathrm{w}_3$ and $\displaystyle \mathrm{w}_4$ represent work done (in calories) in the processes $\displaystyle 1$, $\displaystyle 2$, $\displaystyle 3$ and $\displaystyle 4$, respectively; $\displaystyle \Delta \mathrm{U}_2$ and $\displaystyle \Delta \mathrm{U}_4$ are changes in the internal energy for the processes $\displaystyle 2$ and $\displaystyle 4$, respectively.
[use $\displaystyle \mathrm{R}=2$ cal $\displaystyle \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ ]
The correct option isOfficial answer
From NTA’s final answer key for this paper.
(1)
$\displaystyle \mathrm{w}_1+\mathrm{w}_3=-2 \mathrm{~T}_1 \ln \frac{\mathrm{~V}_2}{\mathrm{~V}_1}-2 \mathrm{~T}_2 \ln \frac{\mathrm{~V}_4}{\mathrm{~V}_3}$
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NEET (UG) 2026 Chemistry question, with the answer from NTA’s final answer key. Where our answers come from.