Ideal Gas Law

[sizillyd]

What is the volume of 0.1 moles of a gas behaving ideally at 700 torr and 37 degrees Celcius? (R= .0821 (L*atm/mol*K))

A) (.1^2)(310)(700)
------------------
760

B) (0.1^2)(37)(760)
-----------------
700

C) (0.1)(310)(760)
------------------
700

D) (0.1^2)(310)(760)
-----------------
700

I assume we use PV=nRT

Ok, I can see how they assumed (0.1^2) because R can be rounded to 0.1
B is wrong because its not in Kelvin. C is wrong because 0.1 is not squared. I picked A, because we need to convert torr to atm for this equation to work. The correct answer is D.
What am I missing?😕

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[RogueUnicorn]

P = 700/760 ATM.

Divide nRT by P means you flip the top and bottom to get n*R*760/700

 

[Phantastic]

PV=nRT

assume R ~= 0.1,

V=nRT/P

n = 0.1
T = 37 C +273 K = 310 K
P=700 torr * (1 atm / 760 torr) = 700/760
but don't forget that it's on the denominator!

so...

V=(0.1)(0.1)(310) / (700/760)

so...760 ends up on top, not on the bottom. They sort of throw you a bone by having 3 of the choices with the 760 on top and the 700 on the bottom. Hope you can see the simple mistake.

rawwwr you beat me to it hehe

 

[sizillyd]

I see what I did. Thanks a lot. I should write out every step. Stupid mistakes will kill ya.