Question

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

• A. $6.17\times {10}^{-21}J$
• B. $6.17\times {10}^{-22}J$
• C. $6.17\times {10}^{-20}J$
• D. $6.16\times {10}^{-20}J$

Answer 1

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

The average kinetic energy can easily be determined by the formula :
$3/2KT$

Where K is the Boltzmann constant which is equal to $1.38\times {10}^{-23}$J/K

T is the temperature in Kelvin

25 degree Celsius = 298 Kelvin

Average kinetic energy = $3/2$ ×$1.38\times {10}^{-23}$ × 298 = $6.2\times 10^{-21}$J

So the answer will be $6.2\times 10^{-21}$ J