Question

At what temperature r.m.s. speed of air molecules doubles of that at N.T.P. is

• A. 819°C
• B. 719°C
• C. 909°C
• D. None of these

Answer 1

Answer: (A)

819°C

Answer 2

$v_{rms} \propto \sqrt{T}$Ž $\frac{v_{1}^{2}}{v_{2}^{2}} = \frac{T_{1}}{T_{2}}$Ž $\frac{v^{2}}{4v^{2}} = \frac{273}{T_{2}}$

Ž$T_{2} = 1092K = 819{^\circ}C$