Question

At T(K), the ratio of kinetic energies of 4 g of $H_{2\left(g\right)}$ and 8 g of $O_{2\left(g\right)}$ is:

• A. 1:4
• B. 4:1
• C. 2:1
• D. 8:1

Answer 1

The correct option is D 8:1

At a given temperature, the average kinetic energy of a gas molecule is constant. Hence, the ratio of kinetic energies of 4 g of $H_2\left(g\right)$ and 8 g of $O_2\left(g\right)$ is equal to the ratio of their number of moles.

It is-

$\frac{\frac{4}{2}}{\frac{8}{32}}=\frac{8}{1}$

Note: The molar masses of $H_2\left(g\right)$ and $O_2\left(g\right)$ are 2 g/mol and 32 g/mol respectively.

Option D is correct.