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Carnivorous Sheep

Baa?21248 Posts

February 22 2010 09:54 GMT

#21

On February 22 2010 18:48 mOnion wrote:

my questions are in the quote ^^^

Bah I'm basically stupid, the methodology I gave you was for the combustion of an organic compound (CxHyOz), which necessitated figuring out exactly how much mass of the element, specifically O, is in the compound and not in the air.

Because the three components of this compound are separated out into three separate compounds on the right side you can basically ignore everything I said and just go with what the other people said, my bad if I confused you T_T

Malongo

Chile3479 Posts

February 22 2010 09:55 GMT

#22

0.458g CO2 => 0.125g C+ 0.333g O
0.374g H2O => 0.0416g H + 0.332g O
0.145g N2 => 0.145g N

====> 0.665g O + 0.125g C + 0.0416g H + 0.145g N in the left side.

====> 0.312g of dimethylhydrazine = x* 12*0.312/(12*x+1*y+14*z) g C= 0.125g C
====> 0.312g of dimethylhydrazine = y* 1*0.312/(12*x+1*y+14*z) g H = 0.0416g H
====> 0.312g of dimethylhydrazine = x* 14*0.312/(12*x+1*y+14*z) g N = 0.145g N

Then solve the 3x3 system.
am i right¿
IM right¿

TheBeardedWonder

United States67 Posts

February 22 2010 09:56 GMT

#23

He's looking for the empirical formula, not the molecular one.
The other people are right.
I suggest learning to find the molecular formula since it'll be more helpful later on.

mOnion

United States5660 Posts

February 22 2010 09:56 GMT

#24

On February 22 2010 18:54 Carnivorous Sheep wrote:

Show nested quote +

lol its fine dude, you can do no wrong while trying to help, ty so much for the help! everyone in thread was amazing

figured it out, should blow this test outta the water with TL power behind me ^_^

mOnion

United States5660 Posts

February 22 2010 09:58 GMT

#25

On February 22 2010 18:56 TheBeardedWonder wrote:
He's looking for the empirical formula, not the molecular one.
The other people are right.
I suggest learning to find the molecular formula since it'll be more helpful later on.

yeh yeh we find the molecular formula in the subsequent question

using the empirical formula find the molecular formula if the weight of dimethylhydrazine is 60g/mol.

which is simple obv once you have empirical ^_^

nanomate

4 Posts

February 22 2010 12:22 GMT

#26

nanomate

4 Posts

February 22 2010 12:24 GMT

#27

Its C2H8N2

1 mole of CxHyNz makes =

x = moles of CO2 = 0.0104 moles
y/2 = moles of H2O = 0.0208 moles
z/2 = moles of N2 = 0.00521 moles

divide by smallest number of moles (because it is the limiting product of the reaction)
so x/z, y/z, z/z

you get ratios of C= 2 H = 8, and N = 2

So its C2H8N2