In the case of hydrogen and helium the van der Waals' forces are-

1. Strong                 

2. Very strong

3. Weak                   

4. None of the above

With the increase of pressure, the mean free path:

1. decreases                             

2. increases

3. becomes zero                       

4. remains the same

The compressibility factor of an ideal gas is:

1. zero                         

2. infinite

3. 1                               

4. -1

The correct value of the gas constant 'R' is close to 

1. 0.082 L atm K

2. 0.082 L atm K^-1 mol^-1

3. 0.082 L atm^-1 K mol^-1

4. 0.082 L^-1 atm^-1 K mol

The partial pressure of a dry gas is:

1. less than that of wet gas

2. greater than that of wet gas

3. equal to that of wet gas

4. none of the above

The number of molecules present in 1 mL of gas or vapor at STP is:

1. called Loschmidt's number

2. equal to 2.617 x 10¹⁹ per mL

3. both (1) and (2)

4. none of the above

 Air at sea level is dense. This is a practical application of:

1. Boyle's law                         

2. Charles' law

3. Avogadro's law                   

4. Dalton's law

In van der Waals' equation of state of the gas, the constant 'b' is a measure of:

1. Intermolecular collisions per unit volume

2. Intermolecular attraction

3. Volume occupied by molecules

4. Intermolecular repulsions

For 1 mole of gas, the average kinetic energy is given as E. The u_rms of gas is :

1. [2E/M]^1/2

2. [3E/M]^1/2

3. [2E/3M]^1/2

4. [3E/2M]^1/2

600 cc of a gas at a pressure of 750 mm is compressed to 500 cc. Taking the temperature to remain constant, the increase in pressure is:                                         

1. 150 mm                       

2. 250 mm

3. 350 mm                      

4. 450 mm