The States of matter : Numerical Questions : Part-(2):

(1) The rms speed of an ideal gas at 27°C is 0.3 ms–1 . Its rms speed at 927°C (in ms–1) is

(2) The compressibility factor for 1 mole of a van der Waals gas at 0oC and 100 atm pressure is found to be 0.5. Assuming that the volume of a gas molecule is negligible, calculate the van der Waals constant, a.

(3) Two moles of ammonia gas are enclosed in a vessel of 5 litre capacity at 27oC. Calculate the pressure exerted by the gas, assuming that (i) the gas behaves like an ideal gas (using ideal gas equation). (ii) the gas behaves like a real gas (using van der Waal’s equation). Given that for ammonia, a = 4.17 atm litre2 mol–2 and b = 0.037 litre mol–1

(4) 1 mole of CCl4 vapours at 77oC occupies a volume of 35.0 L. If vander waal’s constants are a = 20.39 L 2 atm mol–2 and b = 0.1383 L mol–1, calculate compressibility factor Z under (a) low pressure region. (b) high pressure region.

(5) What is Vander waals equation of state of a real gas ?

(6) Calculate the mass of mercuryin a uniform column, 760 mm high and 1.00 cm2 in cross-sectional area. Is there any change in (a) mass and (b) pressure of column of same height but with 2.00 cm2 cross sectional area is taken ? (density of Hg = 13.6 g/cm3 )

(7) A sample of a given mass of a gas at a constant temperature occupies 95cm3 under a pressure of 9.962 × 104N/m2 .At the same temperature, it volume at a pressure of 10.13 × 104 N/m2 is :

(8) A gas occupied a volume of 250 ml at 700 mm Hg pressure and 25°C. What additional pressure is required to reduce the gas volume to its 4/5th value at the same temperature

(9) Volume of a cylinder containing 10 marbles and gas is 1 litre at 2 atm pressure. Now pressure on the cylinder is increased to 4 atm, at which volume becomes 725 ml. Calculate volume of each marble.the

(10) Why liquid have a definite volume but no definite shape?