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.
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). Indices should be entered as normal numbers after the appropriate elements or groups, e.g. H2O for a water molecule.
Parentheses ( ), square brackets [ ] and braces (curly brackets) { } can be used in the formulas. Nested brackets are also allowed, e.g. [Co(NH3)6]Cl3. The degree of nesting is unlimited but all the brackets should be balanced.
You can enter a formula manually or paste the formula copied from a web page or text document (including DOC or PDF file). Indices denoted using <sub> and </sub> html tags (e.g. H2O) as well as denoted using the ‘tiny’ numbers, like ₂ or ₅ , (e.g. H₂O) are supported and automatically converted to normal form.
How to Convert Grams to Moles
The mole (abbreviated mol) is the SI unit of amount of substance. One mole is defined to contain exactly 6.02214076 x 1023 elementary entities (atoms, molecules, ions or electrons). 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.
For example, one mole of carbon dioxide (CO2) contains 6.02214076 x 1023 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.
The molar mass of a substance is the mass of 1 mole of that substance in grams. The amount of substance is the number of moles in the sample. 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. For example, the molar mass of carbon dioxide is approximately 44.01 g/mol.
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, carbon has two stable isotopes (12C and 13C) of ∼ 98.89% and ∼ 1.11% abundance, respectively. 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. So, one mole of carbon with the normal isotopic mix is 12.0107 grams.
The mole is widely used in chemistry as a convenient way to express amounts of reactants and products of chemical reactions. 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:
And although calculations using this formula do not cause difficulties, they can be very laborious when a substance is determined by its chemical formula. In this case, our Mole Calculator will be absolutely indispensable.
Example of Mole Value Calculation
Consider as an example a substance called oxytocin. Oxytocin is a hormone that’s produced in the hypothalamus and released into the bloodstream by the pituitary gland. Its main function is to facilitate childbirth, which is one of the reasons it is called the “love drug” or “love hormone.”
The chemical formula of oxytocin is: C43H66N12O12S2. Suppose now we want to know how many moles of this substance are contained in 10 grams?
First we have to determine the molar mass of oxytocin. Looking at its chemical formula it is not difficult to obtain:
1 mole of C43H66N12O12S2 = (43 moles of С) + (66 moles of H) + (12 moles of N) + (12 moles of O) + (2 moles of S).
By substituting the values of the molar masses of these chemical elements, we get:
Molar mass of oxytocin = 43*12.0107 + 66*1.0079 + 12*14.0067 + 12*15.9994 + 2*32.065 = 1007.1873 (g/mol).
Finally, to find out how many moles of oxytocin there are in 10 grams, we simply divide the given mass of this substance by its found molar mass:
10 g ÷ 1007.1873 g/mol = 0.0099 mol.
The same result can be easily obtained in a fraction of a second using our calculator.
Related calculators
Check out our other chemistry calculators such as Mole Fraction Calculator or Empirical Formula Calculator.