An empty gas cylinder of 40L is to be filled with air (ideal gas) to 5000psia and 25C. The gas cylinder is being filled by a pump that increases its flow by 20 moles per minutes after turned on. How long will it take the pump to fill the tank?

Question

My work:
1st- I converted units to common terms and found that the total number of mols possible was 556 moles using PV=nRT.

2nd- I know that I will need a natural log function of e^(some number)t. I am just not sure how to set that up. This was my first attempt, but I did not feel it correct.

dln(N)=0.20
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dt

e^(.20t)

I am starting to confuse myself now:(

Answer 1

Edit:

e^(.20t)=556