States of Matter · JEE Advanced previous year questions

2025 2 questions

1. Q422025 · 18 May 2025 · Paper 1· Numerical answer

   Molar volume $(V_{\mathrm{m}})$ of a van der Waals gas can be calculated by expressing the van der Waals equation as a cubic equation with $V_{\mathrm{m}}$ as the variable. The ratio (in $\mathrm{mol}\mathrm{d}{\mathrm{m}}^{-3}$) of the coefficient of $V_{\mathrm{m}}^2$ to the coefficient of $V_{\mathrm{m}}$ for a gas having van der Waals constants $a=6.0\mathrm{d}{\mathrm{m}}^6\mathrm{atm}\mathrm{mo}{\mathrm{l}}^{-2}$ and $b=0.060\mathrm{d}{\mathrm{m}}^3\mathrm{mo}{\mathrm{l}}^{-1}$ at 300 K and 300 atm is ____. $\text{Use}$: Universal gas constant (R) = $0.082\mathrm{d}{\mathrm{m}}^3\mathrm{atm}\mathrm{mo}{\mathrm{l}}^{-1}{\mathrm{K}}^{-1}$

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   Answer: -7.2 to -7

2. Q432025 · 18 May 2025 · Paper 1· Numerical answer

   Considering ideal gas behavior, the expansion work done (in kJ) when 144 g of water is electrolyzed completely under constant pressure at 300 K is ____. $\text{Use}$: Universal gas constant (R) = $8.3\mathrm{J}{\mathrm{K}}^{-1}\mathrm{mo}{\mathrm{l}}^{-1}$; Atomic mass (in amu): H = 1, O = 16

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   Answer: -29.95 to -29.8 or 29.8 to 29.95