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~~~~shreyapril~~~~:
By the way one last question whoever can ans it!!

it is an add. math paper

pls see my thread

i am hortly goign to post it

buzywidbizworld:
Guyz can any1 of u plz help me wid this Q.

11 For complete combustion, one molecule of an organic compound needs 8 molecules of oxygen.
What could the formula of this compound be?
A C5H11OH
B C6H9OH
C C6H11OH
D C6H12

The ans is B.C6H9OH
but hw do u derive @ this.
I had thugt it wud b D. but its wrong
Need an xplanation 4 the ans

@d!_†oX!©:
okk see
its says 8 molecules of oxygen
which means a total of 16 O's in the balanced equation
now write the equation:
X + 8O2 ---> CO2 + H2O
so if we have A (C5H11OH)
then to balance for C u have to put 5 b4 CO2, which will make 10 O's so left would be 6 O's but u cannot put a 6....
hey wait...did u say u thought D as the right answer...??so which mark scheme did u check dude...the answer IS D!!!!!!
lol...just re-check man

Ghost Of Highbury:
@adi - D cant be the answer.

C6H12 + 8O2 --> 6CO2 + 6H2O

not balanced.  

C6H9OH + 8O2 -->  6CO2 + 5H2O

now its balanced. so yea just balance and check for the answer.

buzywidbizworld:

--- Quote from: @d!_†oX!© on November 15, 2009, 02:20:35 pm ---okk see
its says 8 molecules of oxygen
which means a total of 16 O's in the balanced equation
now write the equation:
X + 8O2 ---> CO2 + H2O
so if we have A (C5H11OH)
then to balance for C u have to put 5 b4 CO2, which will make 10 O's so left would be 6 O's but u cannot put a 6....
hey wait...did u say u thought D as the right answer...??so which mark scheme did u check dude...the answer IS D!!!!!!
lol...just re-check man

--- End quote ---


i chkd the ms and the ans is still B. D isn't the ri8 ans.

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