Calculate the molecular weight of any chemical compound. Enter a formula like H2O, NaCl, or C6H12O6 to get the molar mass with a detailed elemental breakdown.
Use proper notation: H2O, NaCl, Ca(OH)2, C6H12O6
Molar mass is a fundamental concept in chemistry that represents the mass of one mole of a substance, expressed in grams per mole (g/mol). One mole contains exactly 6.02214076 × 10²³ particles (atoms, molecules, or ions), known as Avogadro's number. The molar mass of a compound is calculated by summing the atomic masses of all atoms in its molecular formula.
For example, water (H₂O) has a molar mass of approximately 18.015 g/mol, calculated as: 2 × hydrogen (1.008 g/mol) + 1 × oxygen (15.999 g/mol) = 18.015 g/mol. This means one mole of water molecules—about 6.022 × 10²³ molecules—has a mass of 18.015 grams. Understanding molar mass is essential for stoichiometric calculations, determining reactant quantities, and predicting product yields in chemical reactions.
Identify all elements in the formula
For glucose (C₆H₁₂O₆), the elements are carbon (C), hydrogen (H), and oxygen (O).
Count atoms of each element
Glucose has 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.
Multiply by atomic mass and sum
(6 × 12.011) + (12 × 1.008) + (6 × 15.999) = 72.066 + 12.096 + 95.994 = 180.156 g/mol
| Compound | Formula | Molar Mass (g/mol) | Common Use |
|---|---|---|---|
| Water | H₂O | 18.015 | Universal solvent |
| Glucose | C₆H₁₂O₆ | 180.156 | Blood sugar, energy |
| Sodium Chloride | NaCl | 58.443 | Table salt |
| Carbon Dioxide | CO₂ | 44.010 | Respiration, carbonation |
| Sulfuric Acid | H₂SO₄ | 98.079 | Industrial chemical |
Note: Atomic masses are based on IUPAC 2021 standard atomic weights. For isotope-specific calculations, use the exact isotope mass instead.
