Question 161. Equal masses of CH₄ and H₂ are mixed in an empty container. The partial pressure of hydrogen in this container expressed as the fraction of total pressure is

Question 162. The activity co-efficient of a solution, which accounts for the departure of liquid phase from ideal solution behaviour

Question 163. An ideal gas can be liquified, because

Question 164. The value of the gas-law constant 'R' is 1.987

Question 165. Volume occupied by one gm mole of a gas at S.T.P. is

Question 166. The number of H⁺ in 1 c.c solution of pH 13 is

Question 167. The density of a liquid is 1500 kg/m³. Its value in gin/litre will be equal to

Question 168. One mole of methane undergoes complete combustion in a stoichiometric amount of air. The reaction proceeds as CH₄ + 2O₂ → CO₂ + 2H₂O. Both the reactants and products are in gas phase. ΔH°298 = - 730 kJ/mole of methane. Mole fraction of water vapour in the product gases is about

Question 169. The boiling points for pure water and pure toluene are 100°C and 110.6°C respectively. Toluene and water are completely immiscible in each other. A well agitated equimolar mixture of toluene and water are prepared. If, at a total pressure of one standard atm. exerted by the vapours of water and toluene, the mole fraction of water Xw in the vapour phase satisfies

Question 170. Pure aniline is evaporating through a stagnant air film of 1 mm thickness at 300 K and a total pressure of 100 KPa. The vapor pressure of aniline at 300 K is 0.1 KPa. The total molar concentration under these conditions is 40.1 mole/m³ . The diffusivity of aniline in air is 0.74xl0⁻⁵m²/s.The numerical value of mass transfer co-efficient is 7.4 x 10⁻³. The rate of evaporation of aniline is 2.97 x 10⁻⁴. Its units are