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The Mole and Molar Mass. What’s missing?. The measurements!. A warm up…. 1 trio = 3 singers 1 six-pack Cola = 6 cans soda 1 dozen donuts = 12 donuts 1 gross of pencils = 144 pencils. Moles of Particles. Contains 6.02 x 10 23 particles
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The Mole and Molar Mass
What’s missing? The measurements!
A warm up… 1 trio = 3 singers 1 six-pack Cola = 6 cans soda 1 dozen donuts = 12 donuts 1 gross of pencils = 144 pencils
Moles of Particles Contains 6.02 x 1023 particles 1 mole (mol) C = 6.02 x 1023C atoms 1 mol H2O = 6.02 x 1023H2O molecules 1 mol NaCl = 6.02 x 1023Na+ ions and 6.02 x 1023Cl– ions
Examples of Moles Moles of elements 1 mol Mg = 6.02 x 1023Mg atoms 1 mol Au = 6.02 x 1023Au atoms Moles of compounds 1 mol NH3 = 6.02 x 1023NH3 molecules 1 mol C9H8O4 = 6.02 x 1023aspirin molecules
Avogadro’s Number 6.02 x 1023 particles 1 mole or 1 mole 6.02 x 1023 particles
Molar Mass Number of grams in 1 mole = the atomic mass 1 mole of C atoms = 12.0 g 1 mole of Mg atoms = 24.3 g 1 mole of Cu atoms = 63.5 g
Learning Check What are the number of atoms in 0.500 mol of Al? 3.01 x 1023 Alatoms 0.500 mol Al 6.02 x 1023 Al atoms 1 mol Al What are the number of moles of S if a sample of S contains 4.50 x 1024 S atoms? 7.5 mol S atoms 4.50 x 1024 S atoms 1 mol S 6.02 x 1023 S atoms
Learning Check Calculate the molar mass A. 1 mole of Br atoms = ________ B. 1 mole of Sn atoms = ________ 79.9 g/mole 118.7 g/mole
Molar Mass of Compounds Mass of compounds in g/mol = the sum of all of its atomic masses
Molar Mass of Compounds CaCl2 (1 mole Ca x 40.1 g/mol) +(2 moles Clx 35.5 g/mol) 1 mole of CaCl2= 111.1 g/mol N2O4 (2 moles N x 14.0 g/mole) + (4 moles O x 16.0 g/mole) 1 mole of N2O4= 92.0 g/mole
Calculations with Molar Mass GramsMoles Atoms/Molecules Use 6.02 x 1023 (particles/mole) Use molar mass (grams/mole)
Moles and Grams Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 3.00 moles of Al? 1. Molar mass of Al= 27.0 g Al 2. Conversion factors for Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al 3. Setup 3.00 mol Al 27.0 g Al 1 mol Al Answer = 81.0 g Al
Learning Check The artificial sweetener aspartame (Nutri-Sweet) formula C14H18N2O5 is used to sweeten diet foods, coffee and soft drinks. How many moles of aspartame are present in 225 g of aspartame?
Solution 1. Molar mass of Aspartame C14H18N2O5 (14 x 12.0) + (18 x 1.01) + (2 x 14.0) + (5 x 16.0) = 294 g/mole 2. Setup 225 g aspartame 1 mole aspartame 294 g aspartame Answer = 0.765 moles of aspartame
Learning Check How many atoms of Aluminum are in 17 grams of Aluminum? 17 grams Al 1 mole Al 6.02 x 1023 atoms 27.0 grams Al 1 mole Al Answer = 3.8 x 1023 atoms of Al