Question

a compound containing only carbon and hydrogen produces 1.80 gCO2 and 0.738 gH2O. Find the empirical formula of the compound. Express your answer as an empirical formula.

Answer 1

Answer:

The empirical formula is CH2

Explanation:

Step 1: Data given

Mass of CO2 produced = 1.80 grams

Mass of H2O produced = 0.738 grams

Step 2: The balanced equation

CxHy + O2 → CO2 + H2O

Step 3: Calculate moles CO2

Moles CO2 = mass CO2 / molar mass CO2

Moles CO2 = 1.80 grams / 44.01 g/mol

Moles CO2 = 0.0409 moles

Step 4: Calculate moles C

In 1 mol CO2 we have 1 mol CO2

In 0.0409 moles CO2 we have 0.0409 mol C

Step 5: Calculate moles H2O

Moles H2O = mass H2O / molar mass H2O

Moles H2O = 0.738 grams / 18.02 g/mol

Moles H2O = 0.04095  moles

Step 6: Calculate moles H

In 1 mol H2O we have 2 moles H

In 0.04095 moles H2O we have 2*0.04095 = 0.0819 moles H

Step 7: Calculate the mol ratio

We divide by the smallest amount of moles

C: 0.0409 / 0.0409 = 1

H: 0.0819 moles / 0.0409 =  2

The empirical formula is CH2