Chemistry - Ideal Gas Question with Solution | TestHub
A closed rigid bulb contains 0.01 mole of inert helium gas and a sample of solid white ammonium chloride, NH4Cl. Assume that the volume of the solid NH4Cl is negligible compared to the volume of the bulb. The pressure of He is measured at 300 K and is found to be 114 mm Hg. The bulb is then heated to 600 K. All the NH4Cl decomposes to NH3(g) and HCl(g). The final total pressure in the bulb after complete decomposition of the solid is 908 mm Hg. Assume ideal behaviour for all gases.
The approximate mass of NH4Cl present initially in the bulb is
Options:
Answer:
Solution:
At 600 K, He alone gives 114 × 600/300 = 228 mm Hg. So p(NH3) + p(HCl) = 908 - 228 = 680 mm, i.e. p(NH3) = 340 mm. n(NH3) = (340 × 1.642)/(62.4 × 600) = 0.0149 ≈ 0.015 mol. Mass of NH4Cl = 0.015 × 53.5 ≈ 0.8 g. Hence (a).
