The cover plate is removed from the gas jars shown iin the diagram. Nitrogen dioxide is a brown gas. After several days, the color of the gas is the same in both of the jars.

Question

What explains this change?

So the picture shows this jar and nitrogen and nitrogen dioxide is separated equally from a cover plate in between.

They gave the following choices below:

A) Equal volumes of nitrogen and nitrogen dioxide contain equal number of molecules.
B) Nitrogen and nitrogen dioxide gases have equal densities.
C)Nitrogen and nitrogen dioxide molecules are in random motion.
D)Nitrogen and nitrogen dioxide molecules diffuse at the same rate.

The answer is C, could you explain why the ans is C and why the other answers are incorrect, thks!

Answer 1

the molecules in random motion cause diffusion into the air, and the NO2 goes into the air.

other answers:
A) TRUE, BUT HAS NOTING TO DO WITH WHAT IS HAPPENING.
B) NOT TRUE, THEY HAVE SAME NUMBER OF MOLECULES AT SAME TEMP/PRESSURE, BUT EACH MOLECULE (n2 VS NO2) HAS DIFFERENT MASS
d) nOPE, THEY DIFFUSE IN ACCORDANCE WITH gRAHAMS LAW.