1. The problem statement, all variables and given/known data

Diatomic carbon dioxide gas (CO2 has molar mass of 44.0 g/mol) is at a temperature of 305 K.

Calculate the most probable speed v_mp.

2. Relevant equations

v_mp = sqrt(2kT/m)


3. The attempt at a solution

v_mp = sqrt(2 * 1.3801 * 10^-23 * 305 / 44)

v_mp = 1.383 * 10^-11

Looks like molecules should be moving a little faster than that. Check your math. The approach is correct, however.

Got it. The answer was 339 m/s. Thanks!

heh, well particles isn't really a physical unit (neither is mol). So what you really have is sqrt(m^2/s^2).

Then

v_mp = sqrt(2 * 1.3801 * 10^-23 (m^2 * kg / (s^2 * K) * 305 K / (44 g/mol / (6.02E23 particles/mol) * kg/1000g)

This ends up with the units being sqrt(m^2/s^2 * particles)

Is that correct?

well, it's a number...

6.023E23 particles/mole

I can see that m is not simply 44 mol. It needs to be in kg. m = M/N_A. The units for M is g/mol. What are the units for N_A, Avogadro's number?

How about you write down the units of all the numerical values you substituted? It is always good practice to do this, and cancel out the units.