Question

The average kinetic energy (in joule) per molecule in 8.0 $g$ of methane at ${27}^{\circ }C$ is $KE=6.21\times {10}^{-y}J$.

The value of $y$ is _____.

Answer 1

Kinetic energy per molecule of a gas:

$KE=\frac{3}{2}\frac{R}{N}T=\frac{3}{2}\times \frac{8.314}{6.023\times {10}^{23}}\times 300=6.21\times {10}^{-21}J$

The value of $y$ is 21.