A cylinder contains hydrogen gas at pressure of 249 kPa and temperature 27°C. Its density is
(Take, $\mathrm{R} = 8.3 \mathrm{J} {\mathrm{mol}}^{-1} {\mathrm{K}}^{-1}$) [NEET 2020]

detailed solution

Correct option is A

Given, pressure, P = 249 kPa = 249 × 103 PaTemperature, T = 27° C = 273 + 27 = 300 KDensity, ρ = ?From ideal gas equation, pV = nRT⇒              pV=mMRT                                                 ∵n=mM⇒             pVM = mRT⇒             pM=mVRT=ρRT                                      ∵mV=ρ⇒            ρ=pMRT=249×103×2×10-38.3×300 kg/m3                               (∵For hydrogen gas, M = 2 g = 2 × 10-3kg)⇒           ρ = 0.2 kg/m3