You will need to refer to a periodic table for proton values. In this notation, the atomic number is not included. Symbol-mass format for the above atom would be written as Cr-52. For an example of this notation, look to the chromium atom shown below:Īnother way to refer to a specific atom is to write the mass number of the atom after the name, separated by a hyphen. The 'A' value is written as a superscript while the 'Z' value is written as a subscript. Both the atomic number and mass are written to the left of the chemical symbol. The composition of any atom can be illustrated with a shorthand notation called A/Z format. 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.Where more than one isotope exists, the value given is the abundance weighted average. This is approximately the sum of the number of protons and neutrons in the nucleus. Relative atomic mass The mass of an atom relative to that of carbon-12. One mole contains exactly 6.022 ×10 23 particles (Avogadro's number) Density is the mass of a substance that would fill 1 cm 3 at room temperature. 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) Then, lookup atomic weights for each element in periodic table: Cu: 63.546, Cl: 35.

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. Computing molar mass step by step First, compute the number of each atom in CuCl: Cu: 1, Cl: 1.

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. Copper(I) oxide appears as a reddish-brown solid with a powdery texture.Ĭomputing molar mass (molar weight)To calculate molar mass of a chemical compound enter its formula and click 'Compute'.

Cu molar mass periodic table