#### Molar Mass, Molecular Weight and Elemental Composition Calculator

Notice: your compound might have oxygen 'O' misspelled as a zero '0'
Molar mass of Na2B4O7 * 10H2O is 381.3721 g/mol
Compound name is borax
Formula in Hill system is B4H20Na2O17

Elemental composition of Na2B4O7*10H2O:
SymbolElementAtomic weightAtomsMass percent
NaSodium22.98976928212.0563 %
BBoron10.811411.3391 %
OOxygen15.99941771.3187 %
HHydrogen1.00794205.2859 %

### Computing molar mass (molar weight)

To calculate molar mass of a chemical compound enter its formula and click 'Calculate!'. In chemical formula you may use:
• Any chemical element
• Functional groups: D, Ph, Me, Et, Bu, AcAc, For, Ts, Tos, Bz, TMS, tBu, Bzl, Bn, Dmg
• parantesis () or brackets [].
• Common compound names.
Examples of molar mass computations: NaCl, Ca(OH)2, K4[Fe(CN)6], CuSO4*5H2O, water, nitric acid, potassium permanganate, ethanol, fructose.

### Computing molecular weight (molecular mass)

To calculate molecular weight of a chemical compound enter it's formula, specify its isotope mass number after each element in square brackets.
Examples of molecular weight computations: C[14]O[16]2, S[34]O[16]2.

### Definitions of molecular mass, molecular weight, molar mass and molar weight

• Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)
• Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.
Weights of atoms and isotopes are from NIST article.