# AP Chemistry

posted by .

When a sample of methyl salicylate weighing 5.287 grams is burned in excess oxygen, 12.24 grams of CO2 and 2.522 grams of H2O are formed. What is the empirical formula for oil of wintergreen?

I know the answer is C8H8O3, I just need help finding out how to solve the problem. Thanks for any help in advance.

• AP Chemistry -

(a) Convert the grams of CO2 to moles of CO2 by dividing grams of CO2 by the molar mass of CO2.
Moles of CO2 = moles of carbon, C. Multiply moles of C by 12.011g/mol to get grams of carbon in the sample.
(b) Find the moles of H2O in a similar way.
Moles of H = (2)(moles of H2O). To get grams of H, multiply moles of H times 1.00794 g/mol
(c) Grams of O in the sample = (grams of sample) - (grams H + grams H)
(d) Convert grams O to moles
(e) Divide moles C, moles H, and moles O by the smallest of the three. This will give you a ratio of three numbers. Multiply those numbers if needed to get three whole numbers. The three whole numbers are the three subscripts in the empirical formula.

• AP Chemistry -

Clarification: In the last step multiply the three numbers in the mole ratio by the same number. Select the smallest multiplier that will give a three whole number ratio. Tose three numbers are your subscripts.

## Similar Questions

1. ### ap chemistry

18. Answer the following question that relate to the analysis of chemical compounds. (a) A compound containing the elements C, H, N, and O is analyzed. When a 1.2359g sample is burned in excess oxygen, 2.241g of CO2(g) is formed. The …
2. ### Chemistry

Assume that a reaction occurs in which unknown substances R and S react to form unknown substances T and U. From the information below, determine the mass of substance T that will be formed if 45.0 grams of substance R reacts with …
3. ### chemistry

Ibuprofen, the active ingredient in Advil, is made up of carbon, hydrogen, and oxygen atoms. When a sample of ibuprofen, weighing 5.000 g, burns in oxygen, 13.86g of CO2 and 3.926 g of water are obtained. What is the simplest formula …
4. ### Chemistry

Calculate the empirical formula and molecular formula of a compound that contains only carbon, oxygen and hydrogen and has a molecular mass of approximately 90. g/mol. Upon combustion of 12.0g of the compund with an excess of oxygen, …
5. ### Chemistry

A certain compound contains carbon, hydrogen , and oxygen. When 1.00 grams of this compound are burned in oxygen gas 1.47 grams of CO2 and 0.600 grams of water are formed. When 2.75 grams of the compound are dissolved in 10.0 grams …
6. ### Chemistry

A certain compound contains carbon, hydrogen , and oxygen. When 1.00 grams of this compound are burned in oxygen gas 1.47 grams of CO2 and 0.600 grams of water are formed. When 2.75 grams of the compound are dissolved in 10.0 grams …
7. ### chemistry

Combustion analysis, Empirical and Molecular formulas, help!?
8. ### chem

when hydrocarbons are burned in a limited amount of air CO as well as CO2 form. When 0.450 grams of a particular hydrocarbon was burned in air, 0.467 grams of CO, 0.733 grams of CO2, and 0.450 grams of H20 were formed. a. What is the …
9. ### chem

When 3.517 grams of a hydrocarbon, CxHy, were burned in a combustion analysis apparatus, 11.59 grams of CO2 and 3.164 grams of H2O were produced. In a separate experiment, the molar mass of the compound was found to be 40.06 g/mol. …
10. ### chemistry

A 8.408 gram sample of an organic compound containing C, H and O is analyzed by combustion analysis and 12.53 grams of CO2 and 3.849 grams of H2O are produced. In a separate experiment, the molar mass is found to be 118.1 g/mol. Determine …

More Similar Questions