🎓 Chemistry • Stoichiometry
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Molecular Formula Calculator
Finds the true molecular formula multiplier n = Molar Mass / Empirical Weight.
Common Molecular Formulas1-click populate
Empirical Formula & Experimental Mass
e.g. CH2O, C3H4O3, HO, CH
From mass spectrometry or freezing depression
True Molecular Formula
C6H12O6
Formula Multiplier: n = 6 (ratio = 6)
Mathematical Derivation
1. Empirical Formula Weight ($M_{emp}$) = 30.026 g/mol
2. Multiplier ($n$) = $\frac{M_{exp}}{M_{emp}} = \frac{180.16}{30.026} = 6 \approx 6$
3. Molecular Formula = (CH2O)$_6$ = C6H12O6
Empirical vs Molecular Scale
What is a Molecular Formula?
A molecular formula gives the actual number of atoms of each element in a single molecule of a compound.
Formula & Step-by-Step Calculation
n = M_molecular / M_empirical, Molecular Formula = (Empirical) × n
Integer multiple relating molecular mass to empirical unit mass.
Worked Step-by-Step Examples
Example 1
Empirical formula CH2O with experimental molar mass 180.16 g/mol
Solution: Molecular Formula: C6H12O6 (Glucose)
• n = 180.16 / 30.026 = 6 ⟹ (CH2O)6 = C6H12O6
Common Real-World & Academic Use Cases
- ✓ Structure elucidation from mass spectrometry
- ✓ Biochemical metabolite identification
- ✓ Petrochemical hydrocarbon analysis
How to Use the Molecular Formula Calculator
1
Enter Empirical Formula
Input empirical formula (e.g. CH2O).
2
Enter Experimental Mass
Input mass in g/mol.
3
Read Molecular Formula
Inspect true molecular formula and multiplier factor n.
Frequently Asked Questions
Q: Can n be 1?
Yes, if the empirical mass equals the molecular mass (e.g. H2O), n = 1 and the empirical and molecular formulas are identical.