ml/min to mol/min [closed]








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After completing a continuous distillation experiment, i am trying to convert my feed flow which i set to 30 ml/min and into mol/min to determine a mass balance equation. 


If i use the equation below to determine my molar feed flow for the liquid. I am not too sure if i would use atmospheric temperature and pressure or use a specific measurement from the experiment.


PV= nRT


n/time = RT/PV




Note that the equation $$pV=nRT$$ is valid for a **gas** only ( more exactly an ideal gas), **not for a liquid** .


### Liquid


$$\frac nt = \frac {V}{t} \cdot \frac{\rho }{ M}$$


Beware of the proper units. Instead of standard ones, these are more suitable for liquids:


$$\mathrm{[mol / s] = [ mL / s ] \cdot \frac {[g/mL]}{[g/mol]}}$$


### Gas


$$\frac nt = \frac {V}{t} \cdot \frac{p }{ RT}$$ For $p$ and $T$, the actual gas conditions apply, including implicit atmospheric pressure.


So eventual pressure correction of the pressure gauge depends on if it measures the absolute pressure, or relative pressure wrt atmospheric one. For the latter, the atmospheric pressure must be added.


Beware of the proper units:


$$\mathrm{[mol / s] = [ m^3 / s ] \cdot \frac {[Pa]}{[J/K/mol][K]}}$$


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