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

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

An ideal gas expands according to PV=constant. On expansion, the temperature of the gas:

1. Will rise.

2. Will drop.

3. Will remain constant.

4. Cannot be determined because the external pressure is not known.

The correct statement for an ideal gas equation is -

1. n is the number of molecules of a gas.

2. V denotes the volume of 1 mole of the gas.

3. n moles of a gas has a volume V.

4. p is the pressure of the gas when only one mole of the gas is present.

The ratio among most probable velocity, mean velocity, and root mean square velocity is given by

1. 1:2:3                           

2. 1: $\sqrt{2}:\sqrt{3}$

3. $\sqrt{2}:\sqrt{3}:\sqrt{\frac{8}{\pi }}$               

4. $\sqrt{2}:\sqrt{\frac{8}{\pi }}:\sqrt{3}$

The compressibility of a gas is less than unity at STP. Therefore:

1. V_m > 22.4 litre                           

2. V_m < 22.4 litre

3. V_m = 22.4 litre                           

4. V_m = 44.8 litre

The numerical value of c_p -c_v is equal to:

1. R             

2. R/M

3. M/R         

4. None of the above

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

Boyle's law is applicable in :

1. Isobaric process

2. Isochoric process

3. Isothermal process

4. Adiabatic process

 The compressibility factor for H₂ and He is usually:

1. >1                                     

2. =1

3. <1                                     

4. either of these