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

Molar mass of Na2Cr2O7 is 261.9675 g/mol
Convert between Na2Cr2O7 weight and moles
 Compound Moles Weight, g Na2Cr2O7

Elemental composition of Na2Cr2O7
ElementSymbolAtomic weightAtomsMass percent
SodiumNa22.98976928217.5516
ChromiumCr51.9961239.6966
OxygenO15.9994742.7518

 Mass percent composition Atomic percent composition

Sample reactions for Na2Cr2O7
 Equation Reaction type Na2Cr2O7 + AlPO4 = Na3PO4 + Al2(Cr2O7)3 double replacement Na2Cr2O7 + S = Na2SO4 + Cr2O3 double replacement Mg(NO3)2 + Na2Cr2O7 = MgCr2O7 + NaNO3 double replacement Pb(NO3)2 + Na2Cr2O7 = PbCr2O7 + NaNO3 double replacement Na2Cr2O7 + Cu(NO3)2 = NaNO3 + CuCr2O7 double replacement

Formula in Hill system is Cr2Na2O7

### Computing molar mass (molar weight)

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• 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 [].
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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.