# Velocity distribution curves general inquiry

1. Oct 11, 2008

### mrjoe2

for a graph that has the velocity as the x axis and the number of molecules as the y axis, i know that as the number of molecules increases, the average velocity will become lower and lower, but what if the molecules being tested are in relative amounts?

you have the equation speed = sqrt (3RT/Molar mass) depend on the MOLAR MASS of the molecule. so if you had air which is composed of 78.08% N2, 20.95 percent O2 and .93 percent Ar by volume. what does the percentages have to do with Molar mass? would i still just do my answer in terms of their molar masses or do i need to take into account their percentages?
my TA in u of t could not answer this question, i was hoping someone here could. thank you

2. Oct 11, 2008

### Staff: Mentor

What are you trying to calculate - average speed of what? Air molecule? No such thing.

3. Oct 11, 2008

### Redbelly98

Staff Emeritus
I don't understand why this would be true.