PV=nRT or 22.4L shortcuts

[RUmolarman]

I'm in full swing now for prep for DAT. And for General Chem, I have noticed for the most part that if there is a calculation involving you needing PV=nRT or PV/T=PV/T, that often times there is some easier stoichiometric shortcut involving the fact that 22.4L=1 mole. This is obviously because the other math is too complicated without a calculator. What are some question examples where this is applicable?

Thanks

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[levyusupov]

if you study from the destroyer, there is everything u have to know about gases. if u dont have the destroyer, get one. it will help you to answer most of your questions in Gchem, and will give you a good clue what to expect on the exam.

GOOD LUCK !!!

 

[zackscoot]

I'm in full swing now for prep for DAT. And for General Chem, I have noticed for the most part that if there is a calculation involving you needing PV=nRT or PV/T=PV/T, that often times there is some easier stoichiometric shortcut involving the fact that 22.4L=1 mole. This is obviously because the other math is too complicated without a calculator. What are some question examples where this is applicable?

Thanks

There are two things that you MUST watch out when using 22.4L = 1 mol.
1. The molecule/compounds in question MUST BE A GAS!!!!!!!!
2. The condition must be STP (standard temperature and pressure) which is 0 oC and 1 ATM. if these are not the condition and you use 22.4L, YOU WILL GET THE QUESTION WRONG!!!

I hope this helped.

 

[KEC029]

the one with density? it's derived from pv=nrt, which is d=pMM/rt