THE “MOLE” A Mole (mol)  is a unit of measurement used for counting very small things (atoms, molecules, etc.) A mole of something is similar to a dozen of something 1 dozen elephants = 12 elephants 1 dozen pencils = 12 pencils 1 dozen chemistry students = 12 chemistry students How are 1 dozen elephants similar to 1 dozen pencils? 1 Mole  = 6.02 x 1023 of anything    Or 602,000,000,000,000,000,000,000 Also known as Avogadro’s Number 1 mole of elephants = 6.02 x 1023 elephants 1 mole of pencils = 6.02 x 1023 pencils 1 mole of chem students = 6.02 x 1023 chem students Or, 1 mole of copper atoms =  6.02 x 1023 copper atoms 1 mole of oxygen atoms = 6.02 x 1023     oxygen atoms How is 1 mole of copper similar to 1 mole of oxygen ? How are they different?

Moles and Mass: Atomic and Formula Mass If 1 mole of an element = (6.02 x 1023 of that element) What would 1 mole of an element weigh? Look on the Periodic Table! The atomic mass given on the periodic table is = grams per mol ( 𝒈 𝟏 𝒎𝒐𝒍 ) or grams in 1 mole! For example:       A) Elements and the Mole (Atomic mass):     1 mole of H atoms weigh = 1.00794 grams     2 moles of H atoms weigh = (2 x 1.00794) = 2.01588 grams     1 mole of  O atoms weigh  = 15.9994 grams     B) Formulas and the Mole (Formula Mass) :     1 mole of water (H2O) would weigh?             2 H = (2 x 1.00794) = 2.01588 grams            +     1 O = 15.9994  grams                               18.01528 grams

2 moles of H2 + 1 mole of O2 → 2 moles of H2O C) Chemical Equations and the Mole: 2 H2  +  1O2  →  2 H2O The coefficients = quantity of each reactant and product in MOLES!     So the above equation really says…….         2 moles of H2  +   1 mole of O2 →  2 moles of H2O So, how much would 2 moles of water weigh? 1 mole of water (H2O) weighs =  18.01528 grams             2 H = (2 x 1.00794) = 2.01588 grams            +     1 O = _            15.99940  grams                             18.01528 grams