H20He19Li18Be17B16C14N13O12F11Ne10Na9Mg8Al7Si6P5S4Cl3Ar2K2Ca molar mass

Molar Mass, Molecular Weight and Elemental Composition Calculator

Molar mass of H₂₀He₁₉Li₁₈Be₁₇B₁₆C₁₄N₁₃O₁₂F₁₁Ne₁₀Na₉Mg₈Al₇Si₆P₅S₄Cl₃Ar₂K₂Ca is 2846.7286 g/mol

Convert between H₂₀He₁₉Li₁₈Be₁₇B₁₆C₁₄N₁₃O₁₂F₁₁Ne₁₀Na₉Mg₈Al₇Si₆P₅S₄Cl₃Ar₂K₂Ca weight and moles

Compound	Moles		Weight, g
H₂₀He₁₉Li₁₈Be₁₇B₁₆C₁₄N₁₃O₁₂F₁₁Ne₁₀Na₉Mg₈Al₇Si₆P₅S₄Cl₃Ar₂K₂Ca

Elemental composition of H₂₀He₁₉Li₁₈Be₁₇B₁₆C₁₄N₁₃O₁₂F₁₁Ne₁₀Na₉Mg₈Al₇Si₆P₅S₄Cl₃Ar₂K₂Ca

Element	Symbol	Atomic weight	Atoms	Mass percent
Hydrogen	H	1.00794	20	0.7081
Helium	He	4.002602	19	2.6715
Lithium	Li	6.941	18	4.3888
Beryllium	Be	9.012182	17	5.3819
Boron	B	10.811	16	6.0763
Carbon	C	12.0107	14	5.9068
Nitrogen	N	14.0067	13	6.3964
Oxygen	O	15.9994	12	6.7443
Fluorine	F	18.9984032	11	7.3411
Neon	Ne	20.1797	10	7.0887
Sodium	Na	22.98976928	9	7.2683
Magnesium	Mg	24.3050	8	6.8303
Aluminum	Al	26.9815386	7	6.6347
Silicon	Si	28.0855	6	5.9195
Phosphorus	P	30.973762	5	5.4402
Sulfur	S	32.065	4	4.5055
Chlorine	Cl	35.453	3	3.7362
Argon	Ar	39.948	2	2.8066
Potassium	K	39.0983	2	2.7469
Calcium	Ca	40.078	1	1.4079

Computing molar mass step by step
First, compute the number of each atom in H₂₀He₁₉Li₁₈Be₁₇B₁₆C₁₄N₁₃O₁₂F₁₁Ne₁₀Na₉Mg₈Al₇Si₆P₅S₄Cl₃Ar₂K₂Ca: H: 20, He: 19, Li: 18, Be: 17, B: 16, C: 14, N: 13, O: 12, F: 11, Ne: 10, Na: 9, Mg: 8, Al: 7, Si: 6, P: 5, S: 4, Cl: 3, Ar: 2, K: 2, Ca: 1 Then, lookup atomic weights for each element in periodic table: H: 1.00794, He: 4.002602, Li: 6.941, Be: 9.012182, B: 10.811, C: 12.0107, N: 14.0067, O: 15.9994, F: 18.9984032, Ne: 20.1797, Na: 22.98976928, Mg: 24.305, Al: 26.9815386, Si: 28.0855, P: 30.973762, S: 32.065, Cl: 35.453, Ar: 39.948, K: 39.0983, Ca: 40.078 Now, compute the sum of products of number of atoms to the atomic weight: Molar mass (H₂₀He₁₉Li₁₈Be₁₇B₁₆C₁₄N₁₃O₁₂F₁₁Ne₁₀Na₉Mg₈Al₇Si₆P₅S₄Cl₃Ar₂K₂Ca) = ∑ Count_i * Weight_i = Count(H) * Weight(H) + Count(He) * Weight(He) + Count(Li) * Weight(Li) + Count(Be) * Weight(Be) + Count(B) * Weight(B) + Count(C) * Weight(C) + Count(N) * Weight(N) + Count(O) * Weight(O) + Count(F) * Weight(F) + Count(Ne) * Weight(Ne) + Count(Na) * Weight(Na) + Count(Mg) * Weight(Mg) + Count(Al) * Weight(Al) + Count(Si) * Weight(Si) + Count(P) * Weight(P) + Count(S) * Weight(S) + Count(Cl) * Weight(Cl) + Count(Ar) * Weight(Ar) + Count(K) * Weight(K) + Count(Ca) * Weight(Ca) = 20 * 1.00794 + 19 * 4.002602 + 18 * 6.941 + 17 * 9.012182 + 16 * 10.811 + 14 * 12.0107 + 13 * 14.0067 + 12 * 15.9994 + 11 * 18.9984032 + 10 * 20.1797 + 9 * 22.98976928 + 8 * 24.305 + 7 * 26.9815386 + 6 * 28.0855 + 5 * 30.973762 + 4 * 32.065 + 3 * 35.453 + 2 * 39.948 + 2 * 39.0983 + 1 * 40.078 = 2846.7286 g/mol

Mass percent composition	Atomic percent composition

Formula in Hill system is C₁₄H₂₀Al₇Ar₂B₁₆Be₁₇CaCl₃F₁₁He₁₉K₂Li₁₈Mg₈N₁₃Na₉Ne₁₀O₁₂P₅S₄Si₆

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, T, Ph, Me, Et, Bu, AcAc, For, Tos, Bz, TMS, tBu, Bzl, Bn, Dmg
parenthesis () or brackets [].
Common compound names.

Examples of molar mass computations: NaCl, Ca(OH)2, K4[Fe(CN)6], CuSO4*5H2O, nitric acid, potassium permanganate, ethanol, fructose, caffeine, water.

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

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.
Mole is a standard scientific unit for measuring large quantities of very small entities such as atoms and molecules. One mole contains exactly 6.022 ×10²³ particles (Avogadro's number)

Steps to calculate molar mass

Identify the compound: write down the chemical formula of the compound. For example, water is H₂O, meaning it contains two hydrogen atoms and one oxygen atom.
Find atomic masses: look up the atomic masses of each element present in the compound. The atomic mass is usually found on the periodic table and is given in atomic mass units (amu).
Calculate molar mass of each element: multiply the atomic mass of each element by the number of atoms of that element in the compound.
Add them together: add the results from step 3 to get the total molar mass of the compound.

Example: calculating molar mass

Let's calculate the molar mass of carbon dioxide (CO₂):

Carbon (C) has an atomic mass of about 12.01 amu.
Oxygen (O) has an atomic mass of about 16.00 amu.
CO₂ has one carbon atom and two oxygen atoms.
The molar mass of carbon dioxide is 12.01 + (2 × 16.00) = 44.01 g/mol.

Lesson on computing molar mass

Weights of atoms and isotopes are from NIST article.

molecular weights calculated today

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