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nAvogadro’s number, commonly used innchemistry, is 6.02n× 1023, andnthat is why we celebrate Avogadro’s number from 6:02 in the morningnuntil 6:02 in the evening on 10/23.
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nAnd,nyes, we who celebrate such a chemical constant arengeeks! Thanks for asking!
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nBut…whynis a day celebrating Avogadro’s number called Mole Day?
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nBut…whynis a day celebrating Avogadro’s number called Mole Day?
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nWell,nAvogadro’s number has to with “moles,” which is an amount. Fornany sort of molecule, one mole is a mass in grams whose number isnequal to the atomic mass of the molecule. A water molecule, as younmay know, is H2O,nand it has an atomic mass of 18. So one mole of water weighs 18ngrams. Butnoxygen gas (two oxygen atoms) has an atomic mass of 32, and so onenmole of oxygen gas weighs 32 grams.
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nInngeneral, one mole of any substance contains Avogadro’s Number ofnmolecules or atoms of that substance. Another way of saying that isnthat 18 grams of water has 6.02 x 10^23 molecules of water, and 32ngrams of oxygen gas has 6.02 x 10^23 molecules of oxygen gas.
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nOnnthis day in chemistry history….
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nOnnOctober 23, 1803…
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nChemistnJohn Dalton read aloud to the Manchester Literary and PhilosophicalnSociety his essay about how water absorbs gases, and he gave atomicnweights for 21 different elements and compounds. From this work onnabsorption of gases and atomic weights, Dalton came up with a much ofnthe modern atomic theory eventually adopted by physics.
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nAnvery appropriate essay to have read on Mole Day!
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nTonlearn more about Mole Day, and to find links to a funny song andnofficial website, check out last year’s post!
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nBynthe way, did you notice…?
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nNationalnMole Day has nothing to do with moles-the-mammals-that-dig?
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