The Combustion Analysis Calculator is a scientific tool used to determine the empirical or molecular formula of a compound based on the masses of carbon dioxide (CO₂) and water (H₂O) produced during combustion. This method is fundamental in analytical chemistry, environmental science, and fuel research for identifying unknown substances and analyzing fuel composition.
This calculator simplifies complex stoichiometric calculations and provides accurate results instantly, reducing manual errors in laboratory analysis.
Combustion analysis is a laboratory technique used to determine the elemental composition of an organic compound. When a compound burns in excess oxygen:
Carbon converts to carbon dioxide (CO₂)
Hydrogen converts to water (H₂O)
Nitrogen may form nitrogen oxides
Other elements may form oxides or remain as residues
By measuring the masses of combustion products, scientists can calculate the amount of each element present in the original compound.
Below are the key equations used in combustion analysis:
Moles of Carbon = Mass of CO₂ × (12.01 / 44.01)
Moles of Hydrogen = Mass of H₂O × (2.016 / 18.015)
Moles of Oxygen = Total sample mass − (mass of C + mass of H)
Empirical Formula Ratio:
Divide all mole values by the smallest mole value
These formulas determine the relative mole ratio of elements in the compound.
Suppose a 1.50 g organic compound produces:
3.30 g CO₂
1.35 g H₂O
Step 1:
Calculate moles of carbon
Moles C = 3.30 × (12.01 / 44.01) = 0.90 mol
Step 2:
Calculate moles of hydrogen
Moles H = 1.35 × (2.016 / 18.015) = 0.15 mol
Step 3:
Determine oxygen mass
Mass O = 1.50 − (mass C + mass H)
Step 4:
Convert oxygen mass to moles and find mole ratios
Result: The empirical formula can be determined from the simplest mole ratio.