Gaseous State - Class 12 MCQ

Oxygen gas is collected by downward displacement of water in a jar. The level of water inside the jar is adjusted to the height of water outside the jar. When the adjustment is made, the pressure exerted by the oxygen is equal to:    

Longest mean free path under similar conditons of P and T stands for:    

Average speed of the molecules of a gas in a container moving in one direction is:

Which gas can be most readily liquefied?    

The liquefaction behaviour of temporary gases like CO₂ approaches that of permanent gases like N₂,O₂, etc., as we go:    

Which is valid at absolute zero?    

Which statement is incorrect?    

An ideal gas obeying kinetic gas equation can be liqefied if:    

Which is lighter than dry air?    

Boyle’s law may be expressed as:    

Which is not correct for gases?    

The ratio of average speed of an oxygen molecule to the rms speed of a nitrogen molecules at the same temperature is:

An open vessel containing air is heated from 300 K to 400 K. The fraction of air originally presemt which goes out of it is:

A 0.5 dm³ flask contains gas A and another flask of 1dm3 conatins gas B at the same temperature. If density of gas A is 3.0 gdm^-3 and of gas B is 1.5 g dm^-3 and molar mass of A= 1/2 molar mass of B, then he ratio of pressure exerted by gases is:

V versus T curves at contant pressure P₁ and P₂ for an ideal gas are shown in figure. Which is correct?

For an ideal gas, the value of 

 A 2.24 litre cylinder containing O₂ gas at 27⁰C and 2 atm is found to develop a leakage. When the leakage was repaired, the pressure dropped to 100 cm of Hg at 27⁰C. The number of mole of gas escaped out during leakage is:    

Four one litre flasks are separately filled with gases, O₂,F₂,CH₄ and CO₂ under the same conditions. The ratio of number of  molecules in these gases.    

A certain gas diffuses from two different vessels A and B. The vessel A has a circular orifice while vessel B has square orifice of length equal to the radius of the orifice of vessel A. The ratio of the rates of diffusion of the gas form vessel A to vessel B, assuming same temperature and pressure is:    

If 1 litre of a gas A at 600 mm and 0.5 litre of gas B at 800 mm are taken in a 2 litre bulb. The resulting pressure is:    

A gaseous mixture contains 1 g of H₂, 4g of He, 7 g of N₂ and 8 g of O₂. The gas having the highest partial pressure is:    

The average speed of an ideal gas molecule at 27⁰C is 0.3 m sec^-1. The average speed at 927⁰C will be...m sec^-1.    

In a experiment during the analysis of a carbon compound, 145 mL of H₂ was collected at 760 mm Hg pressure  and 27⁰C.The mass of H₂ is nearly:    

If a mixture of gases has a total pressure of 100 cm Hg and the partial pressure of nitrogen in the mixture is 25 mm Hg, then the per cent of nitrogen in the mixture is:    

The rms speed of gas molecules at a temperatre 27 K and pressure 1.5 bar is 1x104 cm/sec. If both temperature and  pressure are raised three times, the rms speed of the gas will be:    

In a closed flask of 5 litre, 1.0 g of H₂ is heated from 300 to 600 K. Which statement is not correct?    

Equal moles of hydrogen and oxygen gases are placed in a container with a pin-hole through which both can escape. What fraction of the oxygen escape in the time required for one-half of the hydrogen to escape?