The number of moles of a substance in a sample is obtained by dividing the mass of the sample by the molar mass of the compound: The mole is widely used in chemistry as a convenient way to express amounts of reactants and products of chemical reactions. So, one mole of carbon with the normal isotopic mix is 12.0107 grams. The mass of one mole of 12C is 12.00 grams exactly, whereas the mass of one mole of 13C is 13.00335483521(23) grams. For example, carbon has two stable isotopes ( 12C and 13C) of ∼ 98.89% and ∼ 1.11% abundance, respectively. The molar mass of a substance depends not only on its molecular formula, but also on the distribution of isotopes of each chemical element present in it. For example, the molar mass of carbon dioxide is approximately 44.01 g/mol. For most practical purposes, the magnitude of molar mass is numerically the same as that of the mean mass of one molecule, expressed in daltons. The amount of substance is the number of moles in the sample. The molar mass of a substance is the mass of 1 mole of that substance in grams. This number (known as Avogadro number) was chosen so that the mass of one mole of a chemical compound in grams is numerically equal, for most practical purposes, to the average mass of one molecule of the compound in daltons and roughly equivalent to the number of nucleons (protons or neutrons) in the molecule.įor example, one mole of carbon dioxide (CO 2) contains 6.02214076 x 10 23 molecules, whose total mass is about 44.01 grams and the mean mass of one molecule of carbon dioxide is about 44.01 daltons, roughly a combined atomic mass number of 44. One mole is defined to contain exactly 6.02214076 x 10 23 elementary entities (atoms, molecules, ions or electrons). The mole (abbreviated mol) is the SI unit of amount of substance. H₂O) are supported and automatically converted to normal form. H 2O) as well as denoted using the ‘tiny’ numbers, like ₂ or ₅, (e.g. Indices denoted using and html tags (e.g. You can enter a formula manually or paste the formula copied from a web page or text document (including DOC or PDF file). The degree of nesting is unlimited but all the brackets should be balanced. Parentheses ( ), square brackets and braces (curly brackets) can be used in the formulas. Indices should be entered as normal numbers after the appropriate elements or groups, e.g. ![]() The chemical formula should be entered using the upper case for the first character in the element’s name and the lower case for the second character (compare: Co – cobalt and CO – carbon monoxide). This Mole Calculator finds the quantity of a substance in moles and molar mass of the substance using its chemical formula and known mass of the substance in grams.
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