Density of a gas is found to be 5.46 g/dm³ at 7°C at 2 bar pressure. What will be its density at STP? 

If the density of a gas at the sea level at 0° is 1·29 kg m^–3, what is the molar mass? (Assume that pressure is equal to 1 bar).

34.05 mL of phosphorus vapours weighs 0.0625 g at 546°C and 0·1 bar pressure. what is the molar mass of phosphorus?

2.9 g of a gas at 95°C occupied the same volume as 0·184g of hydrogen at 17°C at the same pressure. What is the molar mass of the gas? 

Calculate the mass of methane in a 9L cylinder at 16 bar and 27°C. (R = 0·08L bar K^–1 mol^–1).

117.

Two flasks A and B have equal volumes. Flask A contains H₂ and is maintained at 300K while the flask B contains an equal mass of CH₄ gas and is maintained at 600K. In which flask is the pressure greater? How many times ?

Pressure of 1g of an ideal gas A at 27° C is found to be 2 bar. When 2g of another ideal gas B is introduced in the same flask at same temperature the pressure becomes 3 bar. Find a relationship between their molecular masses.

Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius 10 m, mass 100 kg is filled With helium at 1·66 bar at 27°C. (Density of air = 1·2 kg m^-3 and R = 0·083 bar dm³ K^–1 mo1^–1). 

State and explain Dalton's law of partial pressure ?