The Mole Chapter 11

Measuring Matter Section 11.1

How much is a mole? Count large # of items is easier when you use counting units like the dozen Chemists use a counting unit called the mole

How is a mole used in chemistry? Mole (mol) is SI base unit used to measure amount of substance 1 mole = Avogadro’s # = 6.022 x 1023 RP Representative particles (RP) = atoms = molecules = FU = electrons = ions

Relate a mole to common counting units 1 dozen eggs = 12 eggs 1 pair of shoes = 2 shoes 1 ream of paper = 500 sheets of paper 1 lb of sugar = 16 ounces of sugar 1 Liter of HCl = 1000 mL of HCl

1 Mole of Representative Particle (RP) Molecule of water Atom of Cu FU of NaCl

How many roses are in 3 ½ dozens? Conversion factor: 12 roses/1 dozen 3.5 dozen x 12 roses/1 dozen = 42 roses

Convert moles  # RP ? RP = given moles x 6.02 x 1023 RP 1 mole

Example ? mole = given RP x 1 mole 6.02 x 1023 RP = 2.65 x 1024 FU ZnCl2 x 1 mole ZnCl2 6.02 x 1023 FU ZnCl2 = 4.40 moles ZnCl2

Convert # RP  moles ? mole = given RP x 1 mole 6.02 x 10 23 RP

Conversion factor: 6.02 x 1023 RP/ 1 mol Example Conversion factor: 6.02 x 1023 RP/ 1 mol ? RP = given moles x 6.02 x 10 23 RP 1 mole = 3.5 moles sucrose x 6.02 x 1023 molecules sucrose 1 mole sucrose =2.11 x 1024 molecules sucrose

Practice Determine the # of atoms in 2.50 mol Zn. 1.51 x 1024 atoms Zn Given 3.25 mol AgNO3, determine # FU 1.96 x 1024 formula units AgNO3 Calculate # molecules in 11.5 mol H2O 6.92 x 1024 molecules H2O

More Practice How many moles contain 5.75 x 1024 atoms of Al? 9.55 mol Al How many moles contain 3.75 x 1024 molecules CO2? 6.23 mol CO2 How many moles contain 3.58 x 1023 formula units ZnCl2? 0.595 mol ZnCl2

Homework p. 311-312 from textbook 1-4 10 Due tomorrow

Mass and the Mole Section 11.2

Relate the mass of an atom to the mass of a mole of atoms 1 dozen eggs and 1 dozen limes are not equal masses Why? Because they are different compositions and size

Avogadro’s Number 6.022 x 1024 Representative Particles ions, atoms, molecules, electrons, FU Lorenzo Romano Amedeo Carlo Avogadro, conte di Quaregna e di Cerreto (1776 - 1856) Photo from http://www.bulldog.u-net.com/avogadro/avoga.html

Mole to Atom? 1 mole = 6.022 x 1024 atoms 1 mole = 6.022 x 1024 molecules 1 mole = 6.022 x 1024 ions 1 mole = 6.022 x 1024 electrons 1 mole = 6.022 x 1024 Formula Units (FU)

Calculate mole  grams ? Grams = given moles x grams from PT 1 mole

Calculate the mass of an element when given # of atoms of element ? grams = atoms x 1 mol x g from PT 6.02 x 1023atoms 1 mol

Calculate # of atoms of element when given mass of element ? Atoms = grams x 1 mol x 6.02 x 1023atoms g from PT 1 mol

Homework Pages 316-318 (12-14) from the textbook Due tomorrow

Moles of Compounds Section 11.3

Recognize the mole relationship shown by a chemical formula

Calculate the molar mass of a compound Add the atomic masses from the periodic table together Ex: Find the molar mass for MgCl2 Molar mass = massMg + 2 (massCl) = 24.305 g + 2(35.453 g) = 24.305 g + 70.906 g = 95.211 g MgCl2

Calculate # moles of compound from given mass of compound

Calculate mass of compound from given # moles of compound

Determine # atoms or ions in a mass of a compound

Empirical & Molecular Formulas Section 11.4

Explain what is meant by the % composition of a compound

Determine the empirical & molecular formulas for compound from mass % & actual mass data

The formula for a hydrate Section 11.5

What is a hydrate?

How does its name reflects its composition?

Determine the formula for a hydrate from laboratory data