What is Mole (unit)?
{{Infobox Unit | bgcolour = [[#0000FF]] | name = Mole | image = Mole carbon-12 diagram.svg | imagesize = 300px | caption = Value of 1 mole based on 12 grams of carbon | standard = [[SI base unit]] | quantity = [[Amount of substance]] | symbol = mol }} '''Mole''' is the [[SI]] [[unit]] used to measure how many [[molecule]]s or [[atom]]s there are. One mole is around 600 sextillion molecules. Scientists use this number because 1 gram of [[hydrogen]] is around 1 mole of [[atoms]]. The exact value of one mole is {{val|6.02214078|e=23}}. This number comes from experiments with [[carbon]] because it's easy to work with.<ref>[https://www.bipm.org/utils/en/pdf/CIPM/CIPM2017-EN.pdf?page=23 CIPM Report of 106th Meeting] {{webarchive|url=https://web.archive.org/web/20180127202612/https://www.bipm.org/utils/en/pdf/CIPM/CIPM2017-EN.pdf?page=23 |date=2018-01-27 }} Retrieved 7 April, 2018</ref><ref>{{cite journal |title=Redefining the Mole |url=https://www.nist.gov/si-redefinition/redefining-mole |journal=NIST |accessdate=24 October 2018|date=2018-10-23 }}</ref> {{val|6.02214078|e=23}} is also called [[Avogadro's number]], which was named after the person who invented it. Anything can be measured in moles, but it is not practical for most tasks because the value is so massive. For example, one mole of grapefruits would be as big as the earth. Because different molecules and atoms do not have the same [[mass]], one mole of one thing does not weigh the same as one mole of something else. Atoms and molecule mass is measured in [[atomic mass unit|amu]]. One amu is equal to one gram per mole. This means that if an atom has a mass of one amu, one mole of this atom weighs one [[gram]]. == Mathematics with the mole == Moles = mass (g) / Relative mass (grams per mole) Example: How many moles are there in 20 grams of hydrogen? A value of 1 can be used for hydrogen's relative mass, although the correct value is slightly larger. So: moles = mass/relative mass = 20/1 = 20 moles. Moles = concentration (mol/dm<sup>3</sup>) x volume (