How can the molar flow rate of a two-gas mixture be calculated?

[vishnu123]

TL;DR Summary

Is there any way to calculate the molar flow rate of the mixture of gaseous?

I have two Gases where i know the molar flow rate of each gas. Is there any way to calculate the molar flow rate of the two gases together or is it just the average of the two molar flow rates?

 

[Borek]

Why average?

If there is 1 mole/min of one gas, and 1 mole/min of other gas, average is 1 mole/min also, and it would tell you individual flows are 0.5 mole/min for both gases - yet we assumed there is 1 mole/min. So in some way and for some reason average doesn't work. Can you think why?

 

[vishnu123]

thank you for your reply. i think the average won't work because of the percentage flow of each gas.

 

[Borek]

What about mass balance?

 

[vishnu123]

ok, I don't know much about that, can you please explain it in detail.

 

[Borek]

Basically: mass is conserved (this is one of the most basic principles governing classical physics and chemistry), mass can't disappear, whatever gets in, must get out.

 

[vishnu123]

so what you say is it has to be divided by the molar mass of the individual gas?
for example 60%of Hydrogen and 40%of nitrogen to calculate it
(.6*molar flow of H2/molar mass of H2)+(0.4*molar flow of N2/molar mass of N2)
is it right?

 

[Borek]

You have lost me. Initially you said you know individual molar flows, now you have 40/60 mixture that can be either v/v or w/w. I have never tried to address the other problem.

What mass conservation tells you is that the mixture of 40/60 is 100% in total.

 

[chemisttree]

Total molar flow should be the sum of the individual molar flow rates.

AND...conservation of mass and conservation of moles is essentially the same thing unless there is a reaction happening which produces a different number of moles of product vs reactants.