(a) Calculate the value of the gas constant, R, if the density of oxygen gas at STP is 1.428 g dm-3. 

(b) Both propane (C3H8) and ethanol (C2H5OH) has similar molar mass which are 44 gmol-1 and 46 g mol-1 respectively. Explain why propane is more volatile than ethanol. 

A mixture containing 28 g of Ar and 14 g of HBr gases are placed in an 8.0 L container at 30 oC. Determine the partial pressure of each gas and the total pressure inside the container.  Assume the gases are ideal. 

(a) A closed cylinder contains hydrogen gas under a pressure of 4.27 atm and at a temperature of 25 °C. when the gas is allowed to expand to a final volume of 10.5 L, the pressure drops to 1.63 atm at the same temperature. Determine the original volume of the gas. 

(b) A mixture of 8.27 g of N2 and 20.4 g of O2 is confined to a volume of 5.0L at 25° C in another closed cylinder. Determine the total pressure and the partial pressure of N2 and O2 in the cylinder. State law is used for the calculation . 

A certain mass of nitrogen gas is added to an vessel of 405 mL containing 0.52 g oxygen. The gas pressure is increased from 745 mmHg to 980 mmHg. Assuming the temperature remains constant, and that the nitrogen gas does not react with oxygen gas, calculate the mass of the added nitrogen. What will happen to the pressure of the closed vessel of nitrogen and oxygen if the temperature is increased? Explain. 

What is an ideal gas? When 17.75 g of Cl2 gas is filled into a 3-L closed container at 27oC, the internal pressure of the container increased to 1.6 atm. Determine whether Cl2 gas behaves as an ideal gas at this condition. State the conditions when a gas deviates from an ideal behaviour. Explain your answer.