Molar mass of calcium oxide
Molar mass of Ca(OH)2 =
Molecular weight calculation:
40.078 + (15.9994 + 1.00794)*2
Element | Symbol | Atomic Mass | # of Atoms | Mass Percent |
Ca | 40.078 | 54.092% | ||
1.00794 | 2.721% | |||
15.9994 | 43.188% |
In chemistry, the formula weight is a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a chemical formula by the number of atoms of that element present in the formula, then adding all of these products together.
Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance.
If the formula used in calculating molar mass is the molecular formula, the formula weight computed is the molecular weight. The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom (or group of atoms) in the formula by the formula weight and multiplying by 100.
A common request on this site is to convert grams to moles. To complete this calculation, you have to know what substance you are trying to convert. The reason is that the molar mass of the substance affects the conversion. This site explains how to find molar mass.
The atomic weights used on this site come from NIST, the National Institute of Standards and Technology. We use the most common isotopes. This is how to calculate molar mass (average molecular weight), which is based on isotropically weighted averages. This is not the same as molecular mass, which is the mass of a single molecule of well-defined isotopes. For bulk stoichiometric calculations, we are usually determining molar mass, which may also be called standard atomic weight or average atomic mass.
Formula weights are especially useful in determining the relative weights of reagents and products in a chemical reaction. These relative weights computed from the chemical equation are sometimes called equation weights.
Finding molar mass starts with units of grams per mole (g/mol). When calculating molecular weight of a chemical compound, it tells us how many grams are in one mole of that substance. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula.
You might also like



![]() |
Calcium Carbide Lumps 50g Bottle Single Detail Page Misc (Consolidated Chemical & Solvents)
|
![]() |
Advanced MAGNESIUM (by InnovixLabs). Highly Bioavailable Bisglycinate + Malate Formula, 150 Vegetarian Capsules. 200 mg Magnesium per serving. Health and Beauty (Innovix Pharma, Inc.)
|
![]() |
Optisource Chewable Vitamin and Mineral Supplement, 120 Count Health and Beauty (Optisource)
|
![]() |
Maybelline New York Superstay 24, 2-step Lipcolor, Endless Ruby 030, 2 Ea Beauty (USA)
|
![]() |
Ultimate Magnesium Citrate | Easy Swallow Capsules | Potent New Formula | 200mg Health and Beauty (Natural Zest)
|