Molecular Formula Calculator

Calculate molecular weight and elemental composition from chemical formulas

Introduction

Molecular formula represents the exact number and type of atoms in a molecule. The molecular weight is the sum of atomic weights of all atoms in the molecule, which is crucial for stoichiometric calculations and chemical analysis.

This calculator helps you determine molecular weight, elemental composition, and mass percentages from any chemical formula, providing essential information for chemical calculations.

How to Use

  1. Enter chemical formula (e.g., "H2O", "C6H12O6")
  2. Use proper element symbols (capital first letter, lowercase second if needed)
  3. Include numbers for multiple atoms (e.g., "O2" for oxygen gas)
  4. Click "Calculate" to get molecular weight and composition
  5. Review element count and mass percentages

Calculator

Examples: H2O, CO2, C6H12O6, NaCl

Calculation Formula

MW = Σ(ni × Ai)

MW: Molecular weight (g/mol)

ni: Number of atoms of element i

Ai: Atomic weight of element i

Σ: Sum over all elements

Use Cases

Chemistry

  • Stoichiometric calculations
  • Reaction planning
  • Concentration calculations
  • Laboratory preparation

Biochemistry

  • Protein analysis
  • DNA/RNA calculations
  • Metabolic pathways
  • Drug formulation

Frequently Asked Questions

What is molecular weight?

Molecular weight is the sum of atomic weights of all atoms in a molecule, expressed in grams per mole (g/mol). It's used for converting between mass and moles in chemical calculations.

How do I write chemical formulas?

Write element symbols with capital first letter and lowercase second if needed. Add subscript numbers to indicate multiple atoms. Examples: H2O (water), CO2 (carbon dioxide), C6H12O6 (glucose).

Why are mass percentages useful?

Mass percentages show the relative contribution of each element to the total molecular weight, useful for understanding composition, purity analysis, and elemental analysis of compounds.

Conclusion

Molecular formula calculations are fundamental to chemistry, providing essential information about molecular composition and properties. This calculator offers quick and accurate analysis of chemical formulas for educational and professional applications.

Understanding molecular weight and elemental composition is crucial for stoichiometry, analytical chemistry, and various fields of science and engineering. Master these calculations to enhance your chemical analysis capabilities.