Page 67 - SP015 Past Years PSPM Chapter 6 -14 Ver 2020

PSPM SP015

PSPM 2004/2005 SF017/2 No. 8

7. Nitrogen (N 2) gas in cylinder at STP has a mass of 112 g. When the gas is compressed
at pressure 10 atm, the temperature of the gas increases to 700 C. Calculate the initial
and final volume of the gas. (Mass of 1 mole of N 2 gas is 28 g.) [4 m]

PSPM 2012/2013 SF016/2 No. 8(c)(ii)

3
8. The pressure of a 50 cm ideal gas at 25 C is 75 Pa. Determine the number of
molecules of the gas. [3 m]

PSPM 2013/2014 SF016/2 No. 8(b)(ii)

9. The mass of an empty 50 litres gas cylinder is 4.8 kg. The cylinder is filled with
nitrogen gas up to pressure of 60 atm. Given the room temperature 29 C and the
molecular mass of nitrogen 28 g, calculate the new mass of the cylinder. [3 m]

Kinetic Theory of Gases

PSPM 2006/2007 SF017/2 No. 14(a)

10. State four assumptions of kinetic theory of gases. [3 m]

PSPM JUN 1999/2000 SF015/2 No. 7(a)

11. State the assumptions required about molecules to obtain the relation between pressure
2
and density of ideal gas, p = <v >. [2 m]
1
3

PSPM 2003/2004 SF017/2 No. 8(b)

12. According to the theory of kinetics gas, the pressure of an ideal gas, p is given as
1
2
p =  <v > where  is the gas density.
3

2
(a) State what is meant by the symbol <v >. [1 m]
2
(b) Express the rms velocity of the molecule in terms of <v >. [1 m]
(c) If the gas is composed of polyatomic molecule, how would the expression in (b)
changes? [1 m]

67