Combustion Analysis Calculator
Determine empirical and molecular formulas from combustion analysis data
Combustion Analysis Calculator
Choose the type of organic compound being analyzed
Initial mass of the organic compound sample
Mass of carbon dioxide produced from combustion
Mass of water vapor produced from combustion
Known molecular mass to determine molecular formula
Combustion Analysis Results
Calculation Details
Moles of elements:
C: 0.00000 mol, H: 0.00000 mol, O: 0.00000 mol
Analysis Tips
Example: CHO Compound
Given Data
Sample mass: 12.915 g
CO₂ produced: 18.942 g
H₂O produced: 7.749 g
Molecular mass: 90.08 g/mol
Results
Element masses:
C: 5.169 g, H: 0.867 g, O: 6.879 g
Empirical formula: CH₂O
Molecular formula: C₃H₆O₃
Analysis Steps
Calculate Element Masses
From CO₂ and H₂O masses
mC from CO₂, mH from H₂O
Convert to Moles
Divide by atomic masses
mol = mass / atomic mass
Find Simplest Ratio
Divide by smallest moles
Empirical formula ratios
Molecular Formula
If molecular mass known
n = MM / EFM
Key Formulas
Carbon Mass
mC = mCO₂ × (12.011/44.010)
Hydrogen Mass
mH = mH₂O × (2×1.008/18.015)
Oxygen Mass
mO = msample - mC - mH
Molecular Formula
n = Molecular Mass / EFM
Analysis Tips
Assumes complete combustion
All C becomes CO₂, all H becomes H₂O
Round ratios to nearest whole numbers
Check for common fractional ratios
Understanding Combustion Analysis
What is Combustion Analysis?
Combustion analysis is a quantitative technique used to determine the empirical formula of organic compounds containing carbon, hydrogen, and oxygen. The compound is completely burned in excess oxygen, and the masses of CO₂ and H₂O produced are measured to calculate the original composition.
Key Assumptions
- •Complete combustion occurs
- •All carbon becomes CO₂
- •All hydrogen becomes H₂O
- •Oxygen comes from sample and combustion air
Calculation Process
1. Mass Calculations
Carbon: mC = mCO₂ × (MC/MCO₂)
Hydrogen: mH = mH₂O × (2MH/MH₂O)
2. Moles Calculation
Divide each mass by respective atomic mass
3. Empirical Formula
Find simplest whole number ratio
4. Molecular Formula
Multiply empirical by n = MM/EFM