Calculate molar mass from chemical formula for lab stoichiometry and solution preparation.
Overview
Molecular weight calculators determine molar mass by parsing a chemical formula and summing each element contribution.
Molar mass is foundational for converting between grams, moles, concentration, and reaction stoichiometry.
Steps
Use proper element symbols and subscripts, such as C6H12O6.
Identify how many atoms of each element are present.
Use periodic table atomic weights for each element.
Compute total molar mass from all element contributions.
Use g/mol for stoichiometry or concentration calculations.
Calculate reagent mass for desired mole or molarity targets.
Math
Molecular Weight (g/mol) = Σ (n_i x atomic weight_i)
Each element contributes its atomic weight times atom count; summing all contributions yields molar mass.
Worked cases
MW = 2(1.008) + 1(15.999) = 18.015
Molar mass of H2O: 18.015 g/mol
MW = 6(12.011) + 12(1.008) + 6(15.999) = 180.156
Molar mass of glucose: 180.156 g/mol
Mass = moles x MW = 0.1 x 58.44
Mass required: 5.844 g NaCl
Why use this
Questions