Only the mass of the most abundant isotope, relative to C (12.0000), is used for these calculations. Simply enter an appropriate subscript number to the right of each symbol, leaving those elements not present blank, and press the ' Calculate' button. The mass calculator on the right may be used to calculate the exact mass of a molecule based on its elemental composition. This table is adapted from Introduction to Mass Spectrometry, by J.T. The factor is multiplied by the number of atoms (n) of the designated element to calculate the intensity contribution from higher mass isotopes. * X represents the relative intensity of the lowest mass ionin an isotopic ion cluster. The molar mass of carbon dioxide is 12.01 + (2 × 16.00) = 44.01 g/mol.Masses Exact Masses & Isotope Abundance Ratios Element.

CO 2 has one carbon atom and two oxygen atoms.Oxygen (O) has an atomic mass of about 16.00 amu.Carbon (C) has an atomic mass of about 12.01 amu.Let's calculate the molar mass of carbon dioxide (CO 2): Add them together: add the results from step 3 to get the total molar mass of the compound.Calculate molar mass of each element: multiply the atomic mass of each element by the number of atoms of that element in the compound.The atomic mass is usually found on the periodic table and is given in atomic mass units (amu). Find atomic masses: look up the atomic masses of each element present in the compound.For example, water is H 2O, meaning it contains two hydrogen atoms and one oxygen atom.

Identify the compound: write down the chemical formula of the compound.

One mole contains exactly 6.022 ×10 23 particles (Avogadro's number)

Mole is a standard scientific unit for measuring large quantities of very small entities such as atoms and molecules.

Molar mass ( molar weight) is the mass of one mole of a substance and is expressed in g/mol.

(1 u is equal to 1/12 the mass of one atom of carbon-12)

Molecular mass ( molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u).

To calculate molecular weight of a chemical compound enter it's formula, specify its isotope mass number after each element in square brackets.Įxamples of molecular weight computations: 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.Ĭomputing molecular weight (molecular mass)

Functional groups: D, Ph, Me, Et, Bu, AcAc, For, Tos, Bz, TMS, tBu, Bzl, Bn, DmgĮxamples of molar mass computations: NaCl, Ca(OH)2, K4, CuSO4*5H2O, nitric acid, potassium permanganate, ethanol, fructose, caffeine, water.

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. Computing molar mass (molar weight)To calculate molar mass of a chemical compound enter its formula and click 'Compute'.

Molar mass cl cl periodic table