Chemical Quantities

Mole: a unit used to count particles in chemistry1 Mole: 6.02 x 10 ^23 (Avogrado's number)1 gram = 1 mole of atomic mass units (amus) ==> 1 gram = 6.02 x 10^23 amu's moles x grams per mole = massPractice: 1 mole of Fe (atomic mass of 56) = 56 grams1 mole of Al (atomic mass of 27) = 27 grams2 moles of Si (atomic mass of 28) = 56 grams 4 moles of O (atomic mass of 16) = 64 grams

Molecular mass: the mass needed to have 6.02 x 10^23 molecules of the substance. ex: the molecular mass of H2O is 18 so you need 18 g of H2O to have 6.02 x 10^23 molecules of water.Formula mass: the mass needed to have 6.02 x 10^23 formula of the substance. ex: the formula mass of NaCl is 58.5 so you need 58.5 g of NaCl to have 6.02 x 10^23 formula units of sodium chloride.Molecular mass: the mass needed to have 6.02 x 10^23 molecules of the substance. ex: the formula mass of H2O is 18 so you need 18 g of H2O to have 6.02 x 10^23 molecules of water.