Question

Equal masses of gaseous N₂ ​and Ar are placed in separate flasks of equal volumes at the same temperature. Tell wheter each of the following statements is true or false. Then explain your answer in each case.

A. There are more moleculaes of N₂ present than atoms of Ar.
​B. The pressure is greater in the Ar flask.
​C. The Ar atoms have greater average speed than te N₂ molecules.
D. The N₂ ​molecules collide more frequently with the walls of the flask than do the Ar atoms.

Answer 1

Since molar mass of N2 is less than that of Ar , the number of moles of N2 will be more than Ar.

So there will be more molecules of N2 than atoms of Ar.

A) True

Pressure is directly proportional to the number of moles by the ideal gas law , pV = nRT ,

so pressure will be higher in N2 flask .

B) false

The average speed of atoms or molecules depend on its mass . Since the mass of Ar is higher than N2 molecules , its speed will be less .

So C) false

Now since the number of molecules of N2 is more than the Ar atoms , in the same volume , it will collide more frequently with the walls of the flask , than the Ar atoms .

So D) True