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Chemistry · PYQ NEET UG 2020
हिन्दीA mixture of \( \mathrm{N}_{2} \) and \( \mathrm{Ar} \) gases in a cylinder contain \( 7 \mathrm{~g} \) of \( \mathrm{N}_{2} \) and \( 8 \mathrm{~g} \) of \( \mathrm{Ar} \). If the total pressure of the mixture of the gases in the cylinder is \( 27 \text{ bar} \), the partial pressure of \( \mathrm{N}_{2} \) is _______. [Atomic masses (in \( \mathrm{g} \text{ mol}^{-1} \)): \( \mathrm{N} = 14, \text{Ar} = 40 \)]
Correct answer · Option 2
15 bar
Explanation
Moles of \( \mathrm{N}_2 = 7/28 = 0.25 \), moles of \( \mathrm{Ar} = 8/40 = 0.2 \). Mole fraction of \( \mathrm{N}_2 = 0.25 / (0.25 + 0.2) = 0.25 / 0.45 = 5/9 \). Partial pressure of \( \mathrm{N}_2 = (5/9) \times 27 = 15 \text{ bar} \).
