Which Compound Could Be X?

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Homework Statement


When 1.11 g of a compound X is completely burnt,1.98 g of carbon dioxide and 0.81 g of water were formed. Which of the following could be X?

A. CH[tex]_{3}[/tex]CH[tex]_{2}[/tex]CH[tex]_{3}[/tex]
B. CH[tex]_{3}[/tex]CH[tex]_{2}[/tex]COOH
C.CH[tex]_{3}[/tex]COCH[tex]_{3}[/tex]
D.C[tex]_{6}[/tex]H[tex]_{5}[/tex]CH[tex]_{2}[/tex]OH

The Attempt at a Solution



I tried

C[tex]_{x}[/tex]H[tex]_{y}[/tex] + {x+[tex]\frac{y}{4}[/tex]}O[tex]_{2}[/tex] [tex]\rightarrow[/tex]
XC0[tex]_{2}[/tex] + [tex]\frac{y}{2}[/tex]H[tex]_{2}[/tex]O

but how about the oxygen atom(s) within compound X?

How can I form a balanced equation for X containing O?

Sorry about the equations and formulae... can't get the subscripts in the right positions.
 
Last edited:
on Phys.org
The only things in the product that you can be absolutely sure come from the reactant is the carbon and hydrogen. So, from the water and CO2, calculate how many moles of C and H you had to begin with. What's the mass of this amount of carbon and hydrogen - is it enough to account for all of the 1.11 g you had to begin with?
 
Got it. Useful hint.Thanks. Answer's B. :smile: