Question

Two compounds are standing at the same temperature. Compound "A" is evaporating more slowly than compound "
b." According to the Kinetic Molecular Theory, which assumption can be made? Compound B has a greater average kinetic energy. Compound A has a greater average kinetic energy. Compound A may have a lower molecular weight. Compound B may have a lower molecular weight.

Answer 1

I believe the answer is compound B may have a lower molecular weight compared to compound A. 
At the same temperature, lighter particles of a compound have a higher average speeds than do heavier particles of another compound. Thus, particles of compound B are lighter than those of compound A and thus they have a higher average speed, hence evaporating faster compared to compound A.

Answer 2

The correct answer its:

D) Compound B may have a lower molecular weight.

hope it helps