Molecular Weight Calculator
Molecular Weight Calculator
Calculate the molecular weight of chemical compounds based on their formulas
Common Compounds
What is Molecular Weight?
Molecular weight, also known as molecular mass, is the mass of a molecule. It is calculated as the sum of the atomic weights of each constituent element multiplied by the number of atoms of that element in the molecular formula.
How to Calculate Molecular Weight
To calculate the molecular weight of a compound:
- Identify all elements in the compound and their respective quantities
- Look up the atomic weight of each element from the periodic table
- Multiply each element's atomic weight by its quantity in the compound
- Sum all the products to get the total molecular weight
Applications of Molecular Weight Calculations
Molecular weight calculations are crucial in various scientific and industrial applications:
- Chemistry: Used in stoichiometric calculations, solution preparation, and reaction analysis
- Pharmaceuticals: Essential for drug formulation, dosage calculations, and pharmacokinetics
- Biochemistry: Used to analyze proteins, DNA, enzymes, and other biomolecules
- Environmental Science: Helps in analyzing pollutants and their environmental impact
- Materials Science: Important for developing new materials with specific properties
Common Examples
Here are some common compounds and their molecular weights:
- Water (H2O): 18.015 g/mol
- Carbon Dioxide (CO2): 44.010 g/mol
- Glucose (C6H12O6): 180.156 g/mol
- Sodium Chloride (NaCl): 58.443 g/mol
- Sulfuric Acid (H2SO4): 98.079 g/mol
Tips for Using the Calculator
To get accurate results with our molecular weight calculator:
- Enter chemical formulas using standard notation (e.g., H2O, not H₂O)
- Use parentheses for complex groups: Ca(OH)2, (NH4)2SO4
- For hydrates, use the dot or middot symbol: CuSO4·5H2O
- Ensure all elements are correctly capitalized (e.g., Na, not NA or na)
- Double-check your formula for accuracy before calculating
Understanding Molecular Composition
The composition tab in our calculator shows the percentage contribution of each element to the total molecular weight. This is particularly useful for:
- Understanding the elemental makeup of compounds
- Analyzing the mass distribution within molecules
- Comparing similar compounds with different elemental ratios
- Verifying chemical formulas through composition analysis