Question

The mass of molecule A is twice that of molecule B. The root mean square velocity of molecule A is twice that of molecule B. If two containers of equal volume have same number of molecules, the ratio of pressure PA/PB will be :

• A. 8 : 1
• B. 1 : 8
• C. 4 : 1
• D. 1 : 4

Answer 1

Answer: (A)

8 : 1

Answer 2

mA = 2 mB

uA = 2 uB

nA = nB

vA = vB

$\frac{P_{A}V_{A}}{P_{B}V_{B}} = \frac{\frac{1}{3}m_{A}n_{A}u_{A}^{2}}{\frac{1}{3}m_{B}n_{B}u_{B}^{2}}$