Question

The average kinetic energy of an ideal gas per molecule in SI unit at $25^{\circ} C$ will be

• A. $6.17 \times 10^{-21} kJ$
• B. $6.17 \times 10^{-21} J$
• C. $6.17 \times 10^{-20} J$
• D. $7.16 \times 10^{-20} J$

Answer 1

Answer: (B)

The average kinetic energy of an ideal gas per molecule in SI units at $25^{\circ} C$ will be $6.17 \times$ $10^{-21} J$
The average kinetic energy of an ideal gas per molecule is given by the expression Average kinetic energy $=\frac{3}{2} kT$
Here, $k$ is boltzmann constant and $T$ is absolute temperature.
$k =1.36 \times 10^{-23} J / K$
$T =25+273=298\, K$
Average kinetic energy $=\frac{3}{2} \times 1.36 \times 10^{-23} J / K \times 298\, K $
$=6.17 \times 10^{-21} J$