Molar Mass Calculator
Enter Formula
Use standard notation: H2SO4, Ca(OH)2 (parentheses not yet supported in this simple version).
Enter a chemical formula like H2O or C6H12O6 to calculate its molar mass.
What is Molar Mass?
Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is numerically equal to the molecular weight or formula weight of a compound.
For example, water (H₂O) has a molar mass of approximately 18.015 g/mol. This means one mole of water molecules weighs about 18 grams.
How to Calculate Molar Mass
To calculate the molar mass of a compound:
- Identify all elements in the chemical formula.
- Find the atomic mass of each element from the periodic table.
- Multiply each atomic mass by the number of atoms of that element in the formula.
- Sum all the contributions to get the total molar mass.
Molar Mass = Σ (Atomic Mass × Number of Atoms)Examples
Example 1: Water (H₂O)
- Hydrogen (H): 1.008 g/mol × 2 = 2.016 g/mol
- Oxygen (O): 15.999 g/mol × 1 = 15.999 g/mol
- Total: 18.015 g/mol
Example 2: Glucose (C₆H₁₂O₆)
- Carbon (C): 12.011 × 6 = 72.066 g/mol
- Hydrogen (H): 1.008 × 12 = 12.096 g/mol
- Oxygen (O): 15.999 × 6 = 95.994 g/mol
- Total: 180.156 g/mol
Why is Molar Mass Important?
Molar mass is essential for stoichiometry, the calculation of reactants and products in chemical reactions. It allows chemists to convert between grams and moles, which is crucial for preparing solutions, conducting experiments, and manufacturing chemicals.
Frequently Asked Questions
Is molar mass the same as molecular weight?
They are numerically identical. Molecular weight is often expressed in atomic mass units (amu or Da), while molar mass is in g/mol.
What is a mole?
A mole is a unit representing 6.022 × 10²³ particles (Avogadro's number). It's like a "dozen" for atoms.
Can this tool handle complex formulas?
This calculator supports simple formulas. For compounds with parentheses like Ca(OH)₂, manually expand to CaO2H2 before entering.