Hi pf,(adsbygoogle = window.adsbygoogle || []).push({});

I have a reaction ## aA → bB ## in a PFR reactor. The simplest equation to write is:

## \frac {dF_A} {dV} = -R ## where ##F## is the Molar flow rate. ##F = C_A*Q## where ##Q## is the volumetric flow rate and ##C_A## is the molar concentration of A.

My textbooks says that if ##a=b## (the total number of moles doesn't change) ##Q## is constant. I don't understand why, can someone explain me? Moreover, sometimes, in the exercise ##Q## is considered constant even if ##a≠b##...

So my question is: "When ##Q## can be considered constant?

Thank you

Ric

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Volumetric flow rate in a PFR reactor

Have something to add?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**