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Chapter 11 The Mole Section 11.1 Please have a highlighter and your periodic table out Standard 3 3b-Students know the quantity one mole is set by defining one mole of carbon 12 atoms to have a mass exactly of 12 grams. 3c- Students know one mole equals 6.02 x1023 particles (atoms or molecules) Words used for counting: Unit Numerical Value Dozen 12 carton Pair 2 Ream 500 paper Gross 144 box Mole 6.02 x 1023 Example Eggs in a Shoes Sheets of Pencils in a Particles Never Changes 1 dozen is always equal to 12 1 mole is always equal to 6.02 ×1023 Avogardro’s number •6.02 ×1023 is also called Avogadro’s number •It was named after this guy: Avogadro of Italy Amedeo Other names for a particle The mole is the SI unit used for counting the amount of a substance 1 mole = 6.02 ×1023 particles Particles can be atoms, ions, molecules, formula units, etc. Multiplying a mole 0.5 moles = 3.01 ×10 23 1 mole = 6.02 ×10 23 2 moles = 1.20 ×10 24 3 moles = 1.80 ×10 24 4 moles = 2.41 ×10 24 How big is a mole 602, 000, 000,000,000,000,000,000 particles 602 SEXTILLION!!!! 1 mole=atomic mass of each element The average atomic mass (on the periodic table) tells you how much one mole of an element weighs (it is also called the molar mass). –Ex. one mole of oxygen atoms weighs 16.00 grams –Ex. one mole of potassium atoms weighs 39.10 grams How did scientist come up with this number? Carbon-12 has exactly 6 protons and 6 neutrons So it has an atomic mass of exactly 12.00 Scientists measured out exactly 12 grams of carbon-12 The sample had 6.02 ×1023atoms of carbon They set 6.02 ×1023to be one mole (like 12 is one dozen) Steps for mole caluculations 1. Start with what is given. 2. (given) x ----------- 3. The units that are given are placed in the denominator 4. Your unknown is placed in the numerator 5. Multiply the top and divide by the bottom Example of time How many minutes are in 120 seconds? Pg 311 examples 1. Determine the number of atoms in 3.00 moles(mol) of Zn? 2. Given 4.00 mole (mol) of AgNO3 determine the number of formula units(FMU). Pg 311 examples continued… 3. Calculate the number of molecules in 11.5 mol of H2O. 4a) 5.75 x 1024 atoms Al how many moles? On your own in your notes needs to be stamped for points 4b) 3.75 x1024 molecules CO2 How many moles? 4c) 3.58 x 1023 Formula units ZnCl2 How many moles? 4d) 2.50 x1020 atoms Fe. How many moles? Molar Mass and Mole to gram calculation Standard 3.d- Students know how to determine the molar mass of a molecule from its chemical formula and a table of atomic masses. 17 Molar Mass The molar mass of a compound can be calculated solving for the sum of the products of each elements’ mass times 18 Examples EX: - - Find the molar mass of the following compounds: P2O5 C6H12O6 Fe2(SO4)3 19 On your own EX: Find the molar mass of the following compounds: - N2O3 - KC2H3O2 - Ca3(PO4)2 20 Moles to Grams EX: - - Perform the following conversions: Convert 5.0 moles of Na to grams Convert 12.0 moles of He to grams Convert 213 grams of NF3 to moles 21 On your own PP: - - Perform the following conversions: Convert 6.50 moles of O to grams Convert 25.0 moles of Fe to grams Convert 0.40 moles of Ne to grams Converting from particles to grams and grams to particles Standard 3.d 23 Particles to grams EX: - Perform the following conversions: Convert 6.5 x 1024 particles of N to grams. Convert 2.8 x 1027 particles of Ca to grams. Convert 5.1 x 1022 particles of K to grams. 24 Grams to particles EX: - Perform the following conversions: Convert 300.0 grams of H2CO3 to particles. Convert 20.0 grams of CuF2 to particles. 25 PP: - Perform the following conversions: Convert 250.0 grams of Na2CO3 to particles. Convert 10.0 of CaF2 to particles.