Author Question: Is there any tricks to knowing which gas law or gas equation to use when you are reading a chemistry word prob? (Read 3368 times)

clippers!

  • Hero Member
  • *****
  • Posts: 828
I don't understand, when I'm reading a chemistry word problem, which formula I'm supposed to use.  I think I have the equations down if I know which equation to plug the numbers into.  I have a quiz tomorrow and we just finished up the chapter yesterday.  Any suggestions.  Anything would be appreciated.  Thanks



curlz

  • Hero Member
  • *****
  • Posts: 538
I think it's good to just remember: PV = nRT

so if the # of moles is constant and you know that R is the ideal gas constant then simply rearranging the equation algebraically gives:

PV/T = constant

and if any of the properties are not given in your word problem, then you can simply take it out of the equation and continue with the properties you are given.

For example, if a question only involves P and V, then your equation of interest will be PV = constant & if a question involves V and T, then ur eqn becomes: V/T = constant etc

Goodluck



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

Yolanda

  • Hero Member
  • *****
  • Posts: 757
remember PV = nRT

then remember this...

1) whatever is constant, move to the right.  the rest move to the left....
2) make 2 conditions 1 and 2.. and make the variable part of the equations =... like this..

PV = nRT..
if V is constant and n is constant (which is usually the case) and R is constant. then...

P/T = nR/V.... the right side is all constants...
P1 /T1 = nR/V
P2 / T2 = nR/V
so
P1 / T1 = P2 / T2  
same for P, n and R being constants...

PV = nRT
V / T = nR/P
V1 / T1 = V2 / T2

etc...

************************
alternately, and this is what I recommend... R is always constant... so

PV = nRT
PV / nT = R...
ie...

(P1V1) / (n1 T1) = (P2 V2 / n2 T2).... if you remember this equation and you cancel out whatever is constant, you should have no problems.  ok?  and fyi, the easy way to remember this equation is... PV = nRT.... PV/nT = R = constant...P1V1/n1T1 = ...

so memorize...

PV = nRT and
(P1V1) / (n1 T1) = (P2 V2 / n2 T2)....



 

Did you know?

Eat fiber! A diet high in fiber can help lower cholesterol levels by as much as 10%.

Did you know?

According to research, pregnant women tend to eat more if carrying a baby boy. Male fetuses may secrete a chemical that stimulates their mothers to step up her energy intake.

Did you know?

Nearly all drugs pass into human breast milk. How often a drug is taken influences the amount of drug that will pass into the milk. Medications taken 30 to 60 minutes before breastfeeding are likely to be at peak blood levels when the baby is nursing.

Did you know?

In women, pharmacodynamic differences include increased sensitivity to (and increased effectiveness of) beta-blockers, opioids, selective serotonin reuptake inhibitors, and typical antipsychotics.

Did you know?

Hypertension is a silent killer because it is deadly and has no significant early symptoms. The danger from hypertension is the extra load on the heart, which can lead to hypertensive heart disease and kidney damage. This occurs without any major symptoms until the high blood pressure becomes extreme. Regular blood pressure checks are an important method of catching hypertension before it can kill you.

For a complete list of videos, visit our video library