Question

The average kinetic energy of an ideal gas per molecule in SI units at ${25}^{0}C$ will be:

• A. $6.17\times {10}^{-21}J{K}^{-1}$
• B. $6.17\times {10}^{-21}kJ{K}^{-1}$
• C. $6.17\times {10}^{20}J{K}^{-1}$
• D. $7.16\times {10}^{-21}J{K}^{-1}$

Answer 1

The correct option is A $6.17\times {10}^{-21}J{K}^{-1}$

The average kinetic energy of molecules is measured by taking the temperature.

It is calculated as $\frac{3}{2}KT$

Where K is Boltzmann constant $=1.38\times {10}^{-23}J{K}^{-1}$

T is temperature is $25+273=298K$

Avg. kinetic energy will be $\frac{3}{2}\times 1.38\times {10}^{-23}\times 298=6.168\times {10}^{-21}J{K}^{-1}$

Option A is correct.