I3He1345Lr8K5Rb8Sr7Sc67Zr78Nb99Mo57Tc89U133Np781Pu123Am123 molar mass

Molar Mass, Molecular Weight and Elemental Composition Calculator

Molar mass of I₃He₁₃₄₅Lr₈K₅Rb₈Sr₇Sc₆₇Zr₇₈Nb₉₉Mo₅₇Tc₈₉U₁₃₃Np₇₈₁Pu₁₂₃Am₁₂₃ is 317713.6023 g/mol

Convert between I₃He₁₃₄₅Lr₈K₅Rb₈Sr₇Sc₆₇Zr₇₈Nb₉₉Mo₅₇Tc₈₉U₁₃₃Np₇₈₁Pu₁₂₃Am₁₂₃ weight and moles

Compound	Moles		Weight, g
I₃He₁₃₄₅Lr₈K₅Rb₈Sr₇Sc₆₇Zr₇₈Nb₉₉Mo₅₇Tc₈₉U₁₃₃Np₇₈₁Pu₁₂₃Am₁₂₃

Elemental composition of I₃He₁₃₄₅Lr₈K₅Rb₈Sr₇Sc₆₇Zr₇₈Nb₉₉Mo₅₇Tc₈₉U₁₃₃Np₇₈₁Pu₁₂₃Am₁₂₃

Element	Symbol	Atomic weight	Atoms	Mass percent
Iodine	I	126.90447	3	0.1198
Helium	He	4.002602	1345	1.6945
Lawrencium	Lr	262.1096	8	0.6600
Potassium	K	39.0983	5	0.0615
Rubidium	Rb	85.4678	8	0.2152
Strontium	Sr	87.62	7	0.1930
Scandium	Sc	44.955912	67	0.9480
Zirconium	Zr	91.224	78	2.2396
Niobium	Nb	92.90638	99	2.8950
Molybdenum	Mo	95.96	57	1.7216
Technetium	Tc	96.906365	89	2.7146
Uranium	U	238.02891	133	9.9643
Neptunium	Np	236.04657	781	58.0247
Plutonium	Pu	238.049560	123	9.2159
Americium	Am	241.056829	123	9.3323

Computing molar mass step by step
First, compute the number of each atom in I₃He₁₃₄₅Lr₈K₅Rb₈Sr₇Sc₆₇Zr₇₈Nb₉₉Mo₅₇Tc₈₉U₁₃₃Np₇₈₁Pu₁₂₃Am₁₂₃: I: 3, He: 1345, Lr: 8, K: 5, Rb: 8, Sr: 7, Sc: 67, Zr: 78, Nb: 99, Mo: 57, Tc: 89, U: 133, Np: 781, Pu: 123, Am: 123 Then, lookup atomic weights for each element in periodic table: I: 126.90447, He: 4.002602, Lr: 262.10963, K: 39.0983, Rb: 85.4678, Sr: 87.62, Sc: 44.955912, Zr: 91.224, Nb: 92.90638, Mo: 95.96, Tc: 96.906365, U: 238.02891, Np: 236.04657, Pu: 238.0495599, Am: 241.0568291 Now, compute the sum of products of number of atoms to the atomic weight: Molar mass (I₃He₁₃₄₅Lr₈K₅Rb₈Sr₇Sc₆₇Zr₇₈Nb₉₉Mo₅₇Tc₈₉U₁₃₃Np₇₈₁Pu₁₂₃Am₁₂₃) = ∑ Count_i * Weight_i = Count(I) * Weight(I) + Count(He) * Weight(He) + Count(Lr) * Weight(Lr) + Count(K) * Weight(K) + Count(Rb) * Weight(Rb) + Count(Sr) * Weight(Sr) + Count(Sc) * Weight(Sc) + Count(Zr) * Weight(Zr) + Count(Nb) * Weight(Nb) + Count(Mo) * Weight(Mo) + Count(Tc) * Weight(Tc) + Count(U) * Weight(U) + Count(Np) * Weight(Np) + Count(Pu) * Weight(Pu) + Count(Am) * Weight(Am) = 3 * 126.90447 + 1345 * 4.002602 + 8 * 262.10963 + 5 * 39.0983 + 8 * 85.4678 + 7 * 87.62 + 67 * 44.955912 + 78 * 91.224 + 99 * 92.90638 + 57 * 95.96 + 89 * 96.906365 + 133 * 238.02891 + 781 * 236.04657 + 123 * 238.0495599 + 123 * 241.0568291 = 317713.6023 g/mol

Mass percent composition	Atomic percent composition

Formula in Hill system is Am₁₂₃He₁₃₄₅I₃K₅Lr₈Mo₅₇Nb₉₉Np₇₈₁Pu₁₂₃Rb₈Sc₆₇Sr₇Tc₈₉U₁₃₃Zr₇₈

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

Please let us know how we can improve this web app.

How to cite?

Choose languageDeutschEnglishEspañol Français Italiano Nederlands Polski Português Русский 中文日本語 한국어