Question

Three closed vessels A, B and C at the same temperature T and contain gases which obey the Maxwellian distribution of velocities. Vessel A contains only $O_2$, B only N$_2$ and C a mixture of equal quantities of $O_2$ and N$_2$. If the average speed of the 0 2 molecules in vessel A is $v_1$,, that of the N$_2$ molecules in vessel B is v$_2$, the average speed of the $O_2$ molecules in vessel C is where, M is the mass of an oxygen molecule

• A. $(v_1+v_2)/2$
• B. $v_1$
• C. $(v_1v_2)^{1/2}$
• D. $\sqrt{3kT/M}$

Answer 1

Answer: (B)

$v_1$

Answer 2

The average speed of molecules of an ideal gas is given by $\, \, \, \, < v > =\sqrt{\frac{8RT}{\pi M}} \, i.e.,, < v > = \sqrt{T}$ for same gas Since, temperatures of A and C are same, average speed of $O_2$ molecules will be equal in A and C i.e. $v_1$