chemistry question

[Cold]

Alright, I'm stuck on this problem. I was wondering if anyone could explain to me the steps to solve it. Ok here we go...

How many moles of O2 are needed to react completely with 52.0 L of CH4 at STP to produce CO2 and H20 according to the reaction:

CH4 + 2O2 --> C02 + 2H20

Edit-Yes I'm a dumbass when it comes to chemistry

 

[kwyckemynd00]

Balancing the reaction yields:
CH4 + 2O2 --> CO2 + 2H2O

You need to find out how many moles per liter of CH4 there are in STP conditions, and you would need a 2:1 ratio of O2 to CH4.

I believe there are .718 grams/liter of CH4 at STP, so lets find the moles.

Carbon is 12g/mol, hydrogen is 1g/mol, so CH4 is 16grams/mol, this gives us a ration of 1mol of CH4 for 16 grams, which is important.

So, .718g/liter * 1mol/16grams = 0.04488 mol/liter CH4.

WE have 52 liters, so:

52 L * 0.04488 mol / L = 2.33 mol CH4

Now, we need 2 moles of oxygen to every one CH4:

2.33mol CH4 * 2mol O2 / mol CH4 = 4.66mol O2 needed.

I believe this is correct, i've not done chemistry in a little while, but its simple stoichiometry. As long as my numbers are correct (i.e. density of CH4 at stp, which i'm unsure of) then the answer should be correct.

Hope this helps.

 

[DAdams91982]

Kwych.. Love the christmas wish list. That is QUITE the gifts.

Adams

 

[Cold]

Thanks a lot Klaus and Kyck. My professor really didn't cover this material like he should have. So a lot of us are confused.

 

[kwyckemynd00]

This might help.

Ah hah! I've still got it

 

[jmh80]

Important to note that Klaus mentions one mole of gas occupies a standard density at STP. I'm pretty sure this can be found via PV=nRT.

(I'll never forget my Chem. 1 teacher in high school calling it "pervert = nert".)

 

[jmh80]

Bah!

Who needs to memorize when one can derive!

(I can't believe I just said that. I can't derive **** - for the most part. I got by in thermodynamics 1 & 2 with memorization.)