Free Molecular Weight Calculator - Molar Mass Made Easy
Calculate molecular weight (molar mass) from chemical formulas. Essential for chemistry calculations, stoichiometry, and solution preparation.
Quick Answer
Calculate molecular weight by adding atomic masses: H2O = 2(1.008) + 16.00 = 18.016 g/mol. Common weights: NaCl = 58.44, CO2 = 44.01 g/mol.
Key Facts about Molecular Weight Calculator:
- MW = sum of atomic weights
- H2O: 18.015 g/mol
- NaCl: 58.44 g/mol
- CO2: 44.01 g/mol
- 1 mole = MW in grams
Why Use Our Molecular Weight Calculator?
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How to Molecular Weight Calculator in 3 Easy Steps
Calculate molecular weight:
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Chemical formula like H2O.
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Sum atomic masses.
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Frequently Asked Questions
Everything you need to know about our molecular weight calculator
How do I calculate molecular weight?
Sum of atomic weights: H2O = 2(1.008) + 16.00 = 18.016 g/mol
Add atomic weights of all atoms in the formula. For H2O: (2 × 1.008) + (1 × 16.00) = 18.016 g/mol. For NaCl: 22.99 + 35.45 = 58.44 g/mol.
What is the difference between molecular weight and molar mass?
Same value; MW is unitless, molar mass is in g/mol
They are numerically equal but have different units. Molecular weight is unitless (daltons). Molar mass is in g/mol. Both describe mass per mole of substance.
What are common molecular weights?
H2O: 18, NaCl: 58, CO2: 44, Glucose: 180 g/mol
Water (H2O): 18.015 g/mol. Glucose (C6H12O6): 180.16 g/mol. NaCl: 58.44 g/mol. CO2: 44.01 g/mol. Ethanol (C2H5OH): 46.07 g/mol.
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