Question

If the vapour behaves ideally at 1000 K, determine the average translational kinetic energy of a molecule.

• A. $1.07\times {10}^{-21}\text{J}$
• B. $1.07\times {10}^{-20}\text{J}$
• C. $2.07\times {10}^{-21}\text{J}$
• D. $2.07\times {10}^{-20}\text{J}$

Answer 1

The correct option is D $2.07\times {10}^{-20}\text{J}$

Average kinetic energy of a molecule,
$\overline{E_k}=\frac{3}{2}{k}_{B}T$ $where,k_B=Boltzmannconstant$
$=\frac{3}{2}\times 1.38\times {10}^{-23}\times 1000\text{J}=2.07\times {10}^{-20}\text{J}$