6.3 mg of boron hydride is contained in a flask of 385 mL at 25.0° C and
a pressure of 11 Torr.
(a) Determine the molar mass of the hydride.
(b) Which of the following hydrides is contained in the flask, BH3
, B2H6 or B4H10?

Steam is contained in a closed rigid container. Initially, the pressure and temperature of the steam are 15 bar and 240 degree C. respectively. The temperature drops as a result of heat transfer to the surroundings. Determine the pressure at which condensation first occurs, in bar. and the fraction of the total mass that has condensed when the temperature reaches 100 degree C. What percentage of the volume is occupied by saturated liquid at the final state?

An air bubble of 1.5 cm' volume is released by a scuba driver ai a depth of 20 m rises to the surface. If the temperature of the water is 7 degree C at 20 m depth and 12 degree C near the surface, which is at atmospheric pressure, calculate the following. the number of moles and molecules of air in the bubble the mass of air in the bubble if the average molar mass of air is 28 g/mol the volume of the air at the surface