A 0.1000 g sample of a compound containing only carbon, hydrogen, and oxygen underwent combustion and 0.1953 g CO2 and 0.1000 g of H2O was produced. What is the empirical formula of the compound?

Write down the equation in terms of the variables.

C_xH_yO_z + O_2 \rightarrow CO_2 + H_2O

From studying this equation, we see that:

C_xH_yO_z + O_2 \rightarrow xCO_2 + \frac{y}{2}H_2O

Find the relative molecular mass of CO2 and that of H2O. Find the number of moles of each that was produced to get the value of x and y. From there, try to balance your equation to get the value of z.

When you're done with that, you will have the molecular formula of the sample. The empirical formula should be easy now. :)