Free Moles to Grams Calculator — Instant Chemistry Conversions
Convert moles to grams, grams to moles, and moles to molecules instantly. Enter any compound name or formula and get step-by-step solutions. Perfect for chemistry homework, stoichiometry, and lab calculations. No sign-up, completely free.
Moles to Grams Calculator — Select conversion type below
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Use mole ratios from a balanced equation to find how much of one substance reacts with or produces another.
How to convert moles to grams — complete guide
How to convert moles to grams
To convert moles to grams, multiply the number of moles by the molar mass of the compound. The molar mass is found by adding the atomic masses of all atoms in the chemical formula.
Na: 2 × 22.990 = 45.98 g/mol
S: 1 × 32.06 = 32.06 g/mol
O: 4 × 16.00 = 64.00 g/mol
Molar Mass = 45.98 + 32.06 + 64.00 = 142.04 g/mol
Step 2: Mass = 7.00 × 142.04 = 994.28 grams
How to convert grams to moles
To convert grams to moles, divide the mass by the molar mass of the compound.
Moles = 58.44 ÷ 58.44 = 1.00 mol
How to convert moles to molecules
Multiply the number of moles by Avogadro's number (6.022 × 10²³) to get the number of molecules.
How to find molar mass
The molar mass of a compound is the sum of atomic masses of all atoms in its formula, expressed in g/mol.
S: 1 × 32.06 = 32.06
O: 4 × 15.999 = 63.996
Molar Mass = 2.016 + 32.06 + 63.996 = 98.072 g/mol
Common compound molar masses
| Compound | Formula | Molar Mass (g/mol) |
|---|---|---|
| Water | H₂O | 18.015 |
| Sodium Chloride | NaCl | 58.44 |
| Sodium Sulfate | Na₂SO₄ | 142.04 |
| Carbon Dioxide | CO₂ | 44.01 |
| Sulfuric Acid | H₂SO₄ | 98.079 |
| Sodium Hydroxide | NaOH | 39.997 |
| Calcium Carbonate | CaCO₃ | 100.09 |
| Glucose | C₆H₁₂O₆ | 180.16 |
| Ammonia | NH₃ | 17.031 |
| Hydrochloric Acid | HCl | 36.461 |
| Ethanol | C₂H₅OH | 46.068 |
| Potassium Permanganate | KMnO₄ | 158.034 |
Common atomic masses for molar mass calculations
These are the most frequently used atomic masses in chemistry homework, stoichiometry, and lab calculations.
Why use this moles to grams calculator?
F.A.Q.
Supporting Subheading
To convert moles to grams, multiply the number of moles by the molar mass of the substance. Formula: Mass (g) = Moles × Molar Mass (g/mol). Example: 2 moles of NaCl (molar mass = 58.44 g/mol) = 2 × 58.44 = 116.88 grams.
First find the molar mass of Na₂SO₄: Na (2×22.990=45.98) + S (32.06) + O (4×16.00=64.00) = 142.04 g/mol. Then: Mass = 7.00 × 142.04 = 994.28 grams. So 7.00 moles of Na₂SO₄ equals 994.28 grams.
To convert grams to moles, divide the mass by the molar mass of the substance. Formula: Moles = Mass (g) ÷ Molar Mass (g/mol). Example: 90 grams of H₂O (molar mass = 18.015 g/mol) = 90 ÷ 18.015 = 4.996 moles.
Molar mass is the mass of one mole of a substance, expressed in g/mol. To calculate it, add the atomic masses of all atoms in the chemical formula. Example: CO₂ → C (12.011) + O×2 (15.999×2 = 31.998) = 44.009 g/mol. Atomic masses are found on the periodic table.
Avogadro’s number is 6.02214076 × 10²³. It represents the number of atoms, molecules, or ions in one mole of any substance. Named after Italian scientist Amedeo Avogadro, it is one of the fundamental constants in chemistry and connects macroscopic measurements (grams) to atomic-scale quantities (individual particles).
Multiply the number of moles by Avogadro’s number: Molecules = Moles × 6.022 × 10²³. Example: 0.5 moles of H₂O = 0.5 × 6.022×10²³ = 3.011×10²³ molecules. To reverse (molecules to moles), divide by Avogadro’s number.
The molar mass of Na₂SO₄ (sodium sulfate) is 142.04 g/mol. Calculation: Na: 2 × 22.990 = 45.980, S: 1 × 32.06 = 32.06, O: 4 × 16.00 = 64.00. Total = 45.980 + 32.06 + 64.00 = 142.04 g/mol.
The molar mass of water (H₂O) is 18.015 g/mol. Calculation: H: 2 × 1.008 = 2.016, O: 1 × 15.999 = 15.999. Total = 2.016 + 15.999 = 18.015 g/mol. This means 1 mole of water weighs 18.015 grams and contains 6.022×10²³ water molecules.
In stoichiometry, use the mole ratio from the balanced chemical equation. Formula: Moles of B = Moles of A × (coefficient of B ÷ coefficient of A). Example: In 2H₂ + O₂ → 2H₂O, if you have 4 moles of H₂, moles of H₂O = 4 × (2÷2) = 4 moles. Then multiply by molar mass to get grams.