Homework Help: Intro to chem

Posted by pooja on Thursday, April 14, 2011 at 1:15pm.

What is the volume of 19.7g of oxygen at STP?

Heres what i got but did not get the same answer..pls tell me where i am wrong!

(grams to moles)
19.7g x 1 mol/ 16.00 = 1.23 mol Oxygen

(Pv=nRT) looking for V
1.23 mol x 0.0821 x 273K / 1.00 atm = 27.57

CORRECT ANSWER is 13.8L!

Intro to chem - DrBob222, Thursday, April 14, 2011 at 5:20pm
You used the atomic weight of Oxygen and not the molar mass (molecular weight).
19.7/32 = 0.6156 moles
V = 0.6156*0.08206*273/ = 13.79L which rounds to 13.8L.
There is another way to do this which is a little easier if you remember that a mole of any gas occupies 22.4L at STP.
(19.7/32)*22.4 = 13.79 = 13.8L
Intro to chem - Pooja, Thursday, April 14, 2011 at 6:52pm
Thank you SO MUCH!

Answer this Question

Related Questions

chem - A steel cylinder of oxygen has a volume of 20.0 L at 22 degree C @ 35 atm...
chemistry - Calculate the number of grams of reactant left over when 28.35 grams...
chemistry - What weight of H2 at STP could be contained in a vessel that holds ...
Chemistry 3A - a quantity of oxygen occupies a volume of 19.2L at STP. How many ...
chem - A steel container of oxygen has a volume of 20.0 L at 22 C @35 atm. What...
#2 chemistry - 2CO(g) + O2(g) ==> 2CO2(g) A. If 16.01 L of oxygen is ...
chem stoichiometry - Acetylene(C2H2) burns in oxygen to form carbon monoxide ...
Chemistry - Could some please tell me if I did this problem correctly? Assume ...
chem - Use the molar volume of a gas at STP to determine the volume (in L) ...
math exponents - i need to write each expression as a product of the same factor...

For Further Reading

First Name:
School Subject:
Answer: