There is a question in my book where we have to find root mean square velocity of oxygen at STP provided the density of oxygen. I know the formula that is sqrt3RT/M. But my answer is not coming right and in the solution they have used the formula sqrt(Pressure/density).

Most popular formula for RMS speed is v

_{rms}=√

^{3RT}/

_{M}. Using the gas equation and density=mass/volume, you can prove that v

_{rms}=√

^{ρ}/

_{p} (try it yourself), where ρ is the density of the gas.

So both of these equations are the same. This means there is something wrong in your calculations.

Most probable error would be that you've not put the values with correct units.

Reply if you're still not getting your answer.