Chem Ppl - Page 3

pbreak · #51 (**permalink**) Jan 28, 04

Quote:

Originally posted by Pussy_Kat
WTF????
:finger: :finger: :finger: :finger:
Damn this all to hell!
k i didnt get that
im good till the fcking coefficient part then i got lost and messed up the entire question

the only reason you divide by the coefficient (which is 5 btw, or multiply by 1/5 like i did) is because for every C3H8 used, 5 O2s are used - so you need 5 times as many O2 molecules as C3H8 molecules to get all of them to react. If we didn't adjust for this the answer would give us O2 in excess which isn't the case... the way I look at it is a little simpler, maybe this will help: think of multiplying the coefficient in when figuring out the g/mol of each molecule in the reaction equation, so that:

C3H8: 3(12) + 8(1) = 44g/mol
5O2: 2(16)*5 = 160g/mol

now don't bother with the coefficient later on and you will get the same answer.

Pussy_Kat · #52 (**permalink**) Jan 28, 04

^^^^ mmmm k
so the oxygen cuz its the limiting reactant get x/5 and C3H8 gets x/its moles right?

pbreak · #53 (**permalink**) Jan 28, 04

Quote:

Originally posted by Pussy_Kat
^^^^ mmmm k
so the oxygen cuz its the limiting reactant get x/5 and C3H8 gets x/its moles right?

your getting there, but that's not quite the way to think about it.

Whether or not O2 is the limiting reagent, you would still use the coefficient - we are using C3H8's coefficient in the equation as well, it just happens to be 1 so you don't notice it. We would use ALL the coefficients of ALL the molecules when figuring these problems out, because they are the RATIOs of one type of molecule to the others - in this case it's a 5 to 1 ratio. Like I said above, the reason the coefficients are there are to balance the equation - which like i said above means that we will need 5 oxygen molecules (O2's) for every propane molecule (C3H8).

I'm not sure how else I can explain this.

Pussy_Kat · #54 (**permalink**) Jan 28, 04

k i kinda get it now
so would i devide the moles by the coefficient
or the coefficient by the moles?

Kraig · #55 (**permalink**) Jan 28, 04

Quote:

Originally posted by Pussy_Kat
anyone who knows ANYTHING about chemisty (11 or higher i dunno you all learn it at one point) pl
i need help with the equations that come with chem
like titration and stoichinometry and what not
plza pm me or leave a post
thank you!
i dont know how to spell stoichnomerty :(

Chem 11? -- Wholly shit you just made me feel really old! I graduated in 96... Hmmmmmm.. if I graduated in 96... that means Cece graduated in like 93-94?

Pussy_Kat · #56 (**permalink**) Jan 28, 04

^ o0o0o0o0 common now kriag
THINK BACK!!!!
lol i have some chemisty for u
lol
:p :p :p :p :p :p :p

Kraig · #57 (**permalink**) Jan 28, 04

English and Business were my Forte... I sucked ass at Math. It's weird, ALL the math brains went to my brother - he has advanced Math, Calculus and all that sheat... I got all the business smarts.

Pussy_Kat · #58 (**permalink**) Jan 28, 04

i suck at math and english im pretty good at socials tho
lol
i dont get this chem sht
i just had to pick a science and this was the one where u got to blow shit up

pbreak · #59 (**permalink**) Jan 28, 04

Quote:

Originally posted by Pussy_Kat
k i kinda get it now
so would i devide the moles by the coefficient
or the coefficient by the moles?

you would divide all the results for moles by their respective coefficient... however the way I did it was to multiply it by the molar mass (g/mol) - look back at my solution or the easier version thereof...

it basically means: I have 32g/mol of O2, but I need 5(32)=160g of O2 per mol of C3H8

pbreak · #60 (**permalink**) Jan 28, 04

I really woulnd't sit on this question for much longer if i was you, you pretty much have the jist of it and their is probably a lot more to learn

cinist · #61 (**permalink**) Jan 28, 04

i took earth science

the teacher was hot

Pussy_Kat · #62 (**permalink**) Jan 28, 04

^ thanks cuz the fact your teacher was smoking is relaly going to help me pass tomorrow :p;)

pbreak what would i define as a subatomic particle?

cinist · #63 (**permalink**) Jan 28, 04

^^^

it sure helped me pass

dayaaamm

M!SKA · #64 (**permalink**) Jan 28, 04

I want to go back to school. I forget allllll of this and it makes me sad :(

www.sparknotes.com for all your highschool homework help needs!

pbreak · #65 (**permalink**) Jan 28, 04

Quote:

Originally posted by Pussy_Kat
^ thanks cuz the fact your teacher was smoking is relaly going to help me pass tomorrow :p;)

pbreak what would i define as a subatomic particle?

protons, neutrons and electrons make up atoms and are therefore subatomic particles... there are other subatomic particles but you don't need to worry bout those.

"Good Riddance" kicks ass by the way.

Hey Cinist - what was his name?? Wasn't Bondi was it?

cinist · #66 (**permalink**) Jan 31, 04

^

it was an outreach teacher, only been around for about two years

:387: