Question

What is the average kinetic energy (in kJ mol-^1) of a hypothetical gas with molecular weight 68 g mol-^1 at a temperature of 72.3 °C? Do not try to identify the gas.

Answer 1

In order to determine the average kinetic energy, use the following formula:

`K=(3)/(2)RT`

where,

R: gas constant = 8.314J/mol*K

T: temperature of the gas = 72.3+ 273 = 345.3K

Replace the previous values of the parameters into the formula for K:

`K=(3)/(2)(\frac{8.314J}{\text{mol}\cdot K})(345.3K)=(4306.23J)/(mol)\approx(4.31kJ)/(mol)`

Hence, the average kinetic energy is approximately 4.31kJ/mol