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

Molar mass of Mg(OH)2 is 58.3197 g/mol
Convert between Mg(OH)2 weight and moles
 Compound Moles Weight, g Mg(OH)2

Elemental composition of Mg(OH)2
ElementSymbolAtomic weightAtomsMass percent
MagnesiumMg24.3050141.6755
OxygenO15.9994254.8679
HydrogenH1.0079423.4566

 Mass percent composition Atomic percent composition

Sample reactions for Mg(OH)2
 Equation Reaction type H3PO4 + Mg(OH)2 = Mg3(PO4)2 + H2O double replacement Mg(OH)2 + HCl = MgCl2 + H2O double replacement HNO3 + Mg(OH)2 = H2O + Mg(NO3)2 double replacement Mg(OH)2 = MgO + H2O decomposition Mg(OH)2 + H2SO4 = MgSO4 + H2O double replacement

Formula in Hill system is H2MgO2

### Computing molar mass (molar weight)

To calculate molar mass of a chemical compound enter its formula and click 'Compute'. In chemical formula you may use:
• Any chemical element. Capitalize the first letter in chemical symbol and use lower case for the remaining letters: Ca, Fe, Mg, Mn, S, O, H, C, N, Na, K, Cl, Al.
• 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.

Molar mass calculator also displays common compound name, Hill formula, elemental composition, mass percent composition, atomic percent compositions and allows to convert from weight to number of moles and vice versa.

### 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.