Gas A has a higher molecular weight than gas B. Which gas has a smaller thermal conductivity?

Gas A has a higher molecular weight than gas B. Which gas has a smaller thermal conductivity?

a. Gas A
b. Gas B
c. Both gases will be having same thermal conductivity.

Correct Answer : a. Gas A

Explanation :

The gases which have higher molecular weights have smaller thermal conductivity, than those with lower molecular weights. Because molecular path of gas molecules decreases with increase in density.