Convert Mass Flow Rate to Molar Flow Rate

In summary, to convert mass flow rate into molar flow rate, divide the mass flow rate by the molecular weight.
  • #1
vishnu123
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TL;DR Summary
can someone tell me the relation between the molar flow rate and density with respect to mass flow rate?
how can i convert mass flow rate into molar flow rate using density of the gas.
 
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  • #2
You can't do it using density. Just divide the mass flow rate by the molecular weight to get the molar flow rate.
 
  • #3
Mass flow may be described with a number of different units. I infer from your question that you may be starting with 'SLPM' or 'SCCM' - these are common mass flow meter units.

Chestermiller is correct, but getting from SLPM to the mass/time units does require the gas density. Specifically, it requires the 'standard' gas density assumed in the 'SLPM' units. In practice, everyone (who manufactures MFMs) uses their own version of 'standard' - mostly 0C vs 25C vs 70F reference temperature - it's an almost 10% error waiting to happen.
 
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  • #4
Thank you Chestermiller and Dullard for clarifying the doubt.
 
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Likes Tom.G
  • #5
Dullard said:
Mass flow may be described with a number of different units. I infer from your question that you may be starting with 'SLPM' or 'SCCM' - these are common mass flow meter units.

Chestermiller is correct, but getting from SLPM to the mass/time units does require the gas density. Specifically, it requires the 'standard' gas density assumed in the 'SLPM' units. In practice, everyone (who manufactures MFMs) uses their own version of 'standard' - mostly 0C vs 25C vs 70F reference temperature - it's an almost 10% error waiting to happen.
You should use the standard ideal molar volume to convert the flow rate from molar units to standard cubic centimeters per minute (sccm). The standard conditions are defined as P= 101325 Pa, T=273.15 K and Z=1.

https://physics.nist.gov/cgi-bin/cuu/Value?mvolstd|search_for=molar+volume

From NIST, 1 sccm is approximately 0.74358 µmol/s.
https://tsapps.nist.gov/publication...4154&msclkid=d34cae6cabff11ec8093320a4d23498a
 

Related to Convert Mass Flow Rate to Molar Flow Rate

What is the difference between mass flow rate and molar flow rate?

The mass flow rate is the amount of mass that passes through a given cross-sectional area per unit time, while the molar flow rate is the amount of substance (measured in moles) that passes through a given cross-sectional area per unit time.

Why is it important to convert mass flow rate to molar flow rate?

Converting mass flow rate to molar flow rate is important because it allows for a more accurate comparison and analysis of different substances, regardless of their molecular weight. It also helps in understanding the chemical reactions and processes involved in a system.

How do you convert mass flow rate to molar flow rate?

To convert mass flow rate to molar flow rate, you need to know the molecular weight of the substance. Then, divide the mass flow rate by the molecular weight to get the molar flow rate. The unit for molar flow rate is usually mol/s or mol/min.

Can you convert molar flow rate to mass flow rate?

Yes, you can convert molar flow rate to mass flow rate by multiplying the molar flow rate by the molecular weight of the substance. The unit for mass flow rate is usually kg/s or kg/min.

What are some practical applications of converting mass flow rate to molar flow rate?

Converting mass flow rate to molar flow rate is commonly used in chemical engineering, where it is important to accurately measure and control the amount of reactants and products in a chemical reaction. It is also useful in industrial processes involving gases, such as in the production of ammonia or in natural gas processing.

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