Question

Complete combustion of 8.50 g of a hydrocarbon produced 27.7 g of CO2 and 8.49 g of H2O. What is the empirical formula for the hydrocarbon?

Answer 1

A hydrocarbon is made up of CHO

The unbalanced equation is C?H?O? + O2 = H2O + CO2

Solution

Part A
Step 1 Convert grams H2O to mol H2O
Step 2 Convert x mol H2O to mol H
Step 3 fConvert mol H to grams H

Part B
Step 1 Convert grams CO2 to mol CO2
Step 2 The ratio of CO2 : C is just 1:1 But it's good practice to write it out
Step 3 Convert mol C to to grams C

Part C
Step 1 Find grams O
mass of compound - mass of H - mass of C
Step 2 Convert mass of O to mol O

Part D
Write out C H O with the mole after each one.
Divide each mole value one by the smallest mole value.
If you have whole numbers (or very close to whole numbers) that is your answer. You answer should be in integers.

If you're getting fractions multiply all mole (by the same number) so that you have whole numbers.

For example if one of your answers is 1.33 multiply all by 3 (1.33 x 3 = 3.99 = 4)