Question

The temperature of a gas is increased from 27${}^o$C to 127${}^o$C. The ratio of its mean kinetic energies will be

• A. 10/9
• B. 9/16
• C. 4/3
• D. 3/4

Answer 1

Answer: (D)

3/4

Ratio of kinetic energies of a gas at two different temperatures is

V${}_{rms}$ = $\frac{1}{2}\times m\times V_{rms1}^2$:$\frac{1}{2}\times m\times V_{rms2}^2$

$\frac{3R{T}_1}{M}:\frac{3R{T}_2}{M}$ (using the standard formula of root mean square velocity)

finally ratio becomes

=$\frac{3}{4}$