Which Compound Could Be X?

[cyt91]

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_{3}CH_{2}CH_{3}
B. CH_{3}CH_{2}COOH
C.CH_{3}COCH_{3}
D.C_{6}H_{5}CH_{2}OH

The Attempt at a Solution

I tried

C_{x}H_{y} + {x+\frac{y}{4}}O_{2} \rightarrow
XC0_{2} + \frac{y}{2}H_{2}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.

 

[alxm]

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?

 

[cyt91]

Got it. Useful hint.Thanks. Answer's B.