Question

Calculate the average translational kinetic energy, ?k, for one mole of gas at 649 K. Translational kinetic energy is sometimes called average kinetic energy.

Answer 1

We have ,Total K.E = n ( 3/2 R T )

Where, n is number of moles of gas, T is temoerature of a gas & R is gas constant.

$\therefore$ Total K.E = 1 mol $\times$ ( 3 /2 ) $\times$ 8.314 J mol ^-1 K ^-1$\times$ 649 K

Total K.E = 8039.7 J     

We have relation , 1 mol Compound = 6.022 $\times$ 10 ²³ molecules

$\therefore$ Average translational K.E = 8039.7 J / ( 6.022 $\times$ 10 ²³ ) 1 = 1.344 $\times$ 10 ^-20 J

ANSWER : Average translational K.E =1.344 $\times$ 10 ^-20 J