10 1 The Mole A Measurement of Matter

10. 1 The Mole: A Measurement of Matter > Daily Question What would be the charge of an iodide ion? Which is larger I? or I 1 - ? 1 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Chapter 10 Chemical Quantities 10. 1 The Mole: A Measurement of Matter 2 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > I can… Perform dimensional analysis to convert between units Recall Avogadro’s number Apply Avogadro’s number to determine the number of representative particles in a substance Calculate representative particles moles Calculate moles representative particles Determine molar mass of a substance 3 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Measuring Matter Chemistry is a quantitative science. • you perform calculations that relate quantities of the reactants in a chemical reaction to quantities of the products. 4 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Measuring Matter Each of these different ways to measure apples can be equated to a dozen apples. • By count: 1 dozen apples = 12 apples • By mass: 1 dozen apples = 2. 0 kg apples • By volume: 1 dozen apples = 0. 20 bushel apples These are approximations for average-sized apples. 5 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Sample Problem 10. 1 > ment of Matter Finding Mass from a Count What is the mass of 90 average-sized apples if 1 dozen of the apples has a mass of 2. 0 kg? 6 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Sample Problem 10. 1 > ment of Matter 1 Analyze List the knowns and the unknown. Use dimensional analysis to convert the number of apples to the mass of 90 apples. KNOWNS number of apples = 90 apples Conversion factors 12 apples = 1 dozen apples = 2. 0 kg apples 7 UNKNOWN mass of 90 apples = ? kg Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Sample Problem 10. 1 > ment of Matter 2 Calculate Solve for the unknown. Multiply the known by conversion factors. The conversion factor used should cancel the previous unit 90 apples × 1 dozen apples 12 apples The unit “apples” cancels the previous unit 8 × 2. 0 kg apples 1 dozen apples = 15 kg apples The unit “dozen apples” cancels the previous unit Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure> ment of Matter If 0. 20 bushel is 1 dozen apples and a dozen apples has a mass of 2. 0 kg, what is the mass of 0. 56 bushel apples? KNOWNS number of apples = 0. 56 bushel apples Conversion factors 12 apples = 1 dozen apples = 2. 0 kg apples UNKNOWN mass of 0. 56 bushel apples = ? kg 9 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > COPY THIS Assume 2. 0 kg of apples is 1 dozen and that each apple has 8 seeds. How many apple seeds are in 14 kg of apples? Known – 14 kg apples Conversion factors: 2. 0 kg apples = 1 dozen 1 apple = 8 seeds Unknown: seeds? 10 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What Is a Mole? Matter is composed of atoms, molecules, and ions. • These is an extremely large number of them in a small sample of a substance so counting these particles is not practical. 11 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What Is a Mole? Think about counting eggs. • It’s easier when the eggs are grouped into dozens. • A dozen is a specified number (12) of things. 12 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What Is a Mole? Counting with Moles Chemists also use a unit that is a specified number of particles, most often atoms or molecules. • The unit is called the mole. • A mole (mol) of a substance is 6. 022 × 1023 representative particles of that substance • The number of representative particles in a mole and is called Avogadro’s number, 6. 022 × 1023 TED Ed TV 13 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > If you had a mole of doughnuts, they would cover the entire Earth in a doughnut-layer five miles deep. 14 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > If you had a mole of basketballs, you could create a new planet the size of the Earth! 15 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > If you received a mole of pennies on the day you were born, and spent a million dollars a second until you died at 100, you’d still have over 99. 99% of your money in the bank! 16 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Counting with Moles The term representative particle refers to atoms, molecules, or formula units. • The representative particle of most elements is the atom. 17 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What Is a Mole? Counting with Moles However, seven elements exist normally as diatomic molecules: H 2, N 2, O 2, F 2, Cl 2, Br 2, and I 2. I Have NO Bright or Clever Friends – you must memorize the diatomic elements • The representative particle of these elements is the molecule. • For ionic compounds, such as calcium chloride, the representative particle is the formula unit, Ca. Cl 2. 18 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What Is a Mole? Counting with Moles A mole of any substance contains Avogadro’s number of representative particles, or 6. 022 × 1023 atoms, ions, molecules or formula units 19 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > COPY THIS Write the correct representative particle (atom , molecule or formula unit) for each of the following. H 2 O KI O 2 Ag 20 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Daily Question What is a mole of substance? 21 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Sample Problem 10. 2 Converting Number of Atoms to Moles Magnesium is a light metal used in the manufacture of aircraft, automobile wheels, and tools. How many moles of magnesium is 1. 25 × 1023 atoms of magnesium? 22 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Sample Problem 10. 2 > ment of Matter 1 Analyze List the known and the unknown. KNOWN number of atoms = 1. 25 × 1023 atoms Mg Conversion factor 1 mol Mg = 6. 022 × 1023 atoms Mg UNKNOWN moles = ? mol Mg 23 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Sample Problem 10. 2 > ment of Matter 2 Calculate Solve for the unknown. Multiply the number of atoms of Mg by the conversion factor. 1. 25 × 1023 atoms Mg × 1 mol Mg 6. 022 × 1023 atoms Mg = 0. 208 mol Mg Why does this answer have three significant figures? 24 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > How many moles is 2. 8 x 1024 atoms of silicon? 25 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > How many moles is 2. 17 x 1023 representative particles of bromine? 26 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What Is a Mole? Converting Between Number of Particles and Moles • A mole of carbon dioxide contains 6. 022 × 1023 (Avogadro’s number) of CO 2 molecules. • 1 mole of CO 2 contains three atoms, so it contains three times 6. 022 × 1023 atoms or 1. 806 × 1024 atoms 27 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Sample Problem 10. 3 Converting Moles to Number of Atoms Propane is a gas used for cooking and heating. How many atoms are in 2. 12 mol of propane (C 3 H 8)? 28 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Sample Problem 10. 3 > ment of Matter 1 Analyze List the knowns and the unknown. The desired conversion is: moles → molecules → atoms. KNOWN number of moles = 2. 12 mol C 3 H 8 Conversion factors 1 mol C 3 H 8 = 6. 022 × 1023 molecules C 3 H 8 1 molecule C 3 H 8 = 11 atoms (3 carbon and 8 hydrogen atoms) UNKNOWN number of atoms = ? atoms 29 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Sample Problem 10. 3 2 Calculate Solve for the unknown. Multiply the moles of C 3 H 8 by the conversion factors. 2. 12 mol C 3 H 8 × 6. 022 × 1023 molecules C 3 H 8 1 mol C 3 H 8 × 11 atoms 1 molecule C 3 H 8 = 1. 40 × 1025 atoms Why does the answer have three significant figures? 30 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > How is a mole similar to a dozen? 31 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > How many atoms are in 1. 14 mol of sulfur trioxide (SO 3)? 32 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > How many carbon atoms are in 2. 12 mol of propane? How many hydrogen atoms are in 2. 12 mole of propane? 33 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Daily Question How many molecules of H 2 O are in 1 mole of H 2 O? 34 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Learning Targets: I can… • Determine molar mass of an element or compound • Calculate moles to grams • Calculate grams to moles 35 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Molar Mass The Mass of a Mole of an Element The atomic mass of an element expressed in grams is the mass of a mole of the element. The mass of 1 mole of an element is its molar mass. • For carbon, the molar mass is 12. 0 g. • For atomic hydrogen, the molar mass is 1. 0 g. 36 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Why are the atomic masses on the periodic table not whole numbers? What is the atomic mass of an element expressed in grams? 37 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Molar Mass The Mass of a Mole of an Element 1 mol of sulfur atoms = 32. 1 g 1 mol of carbon atoms = 12. 0 g 1 mol of iron atoms = 12. 0 g This figure shows one mole of carbon, sulfur, and iron. 38 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measure. Molar Mass > ment of Matter The Mass of a Mole of an Element • The molar mass of an element contains 1 mol or 6. 022 × 1023 atoms of that element. • 1 mole of an element has the mass listed on the periodic table 39 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > How many atoms are contained in the molar mass of an element? Describe how to calculate the molar mass of a compound. 40 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Molar Mass The Mass of a Mole of a Compound To calculate the molar mass of a compound: • determine the number of grams of each element • then add the masses of the elements in the compound. 41 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Molar Mass The Mass of a Mole of a Compound Find the molar mass of SO 3 • the mass of sulfur (S) is 32. 1 g • The mass of three atoms of oxygen: • (O): 3 × 16. 0 g = 48. 0 g • Molar mass of SO 3 is 32. 1 g + 48. 0 g = 80. 1 g • 1 mole of SO 3 has a mass of 80. 1 g. • This is the mass of 6. 022 x 1023 molecules of SO 3. 42 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter Molar Mass > The Mass of a Mole of a Compound 1 mol of paradichlorobenzene (C 6 H 4 Cl 2) molecules (moth crystals) = 147. 0 g 1 mol of glucose (C 6 H 12 O 6) molecules (blood sugar) = 180. 0 g 1 mol of water (H 2 O) molecules = 18. 0 g 43 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Sample Problem 10. 4 Calculating the Molar Mass of a Compound The decomposition of hydrogen peroxide (H 2 O 2) provides sufficient energy to launch a rocket. What is the molar mass of hydrogen peroxide? 44 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Sample Problem 10. 4 2 Calculate Solve for the unknown. Add the results. mass of 1 mol H 2 O 2 = 2. 0 g H + 32. 0 g O = 34. 0 g molar mass of H 2 O 2 = 34. 0 g/mol 45 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Find the molar mass of PCl 3 46 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What is the mass of 1 mole of sodium carbonate? 47 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > What is 1 mole of: Apples? Write a brief set of directions on how to calculate the molar mass of any compound. 48 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > END OF 10. 1 49 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .

10. 1 The Mole: A Measurement of Matter > Glossary Terms • mole (mol): the amount of a substance that contains 6. 02 × 1023 representative particles of that substance • Avogadro’s number: the number of representative particles contained in one mole of a substance; equal to 6. 02 × 1023 particles • representative particle: the smallest unit into which a substance can be broken down without a change in composition, usually atoms, molecules, or ions • molar mass: a term used to refer to the mass of a mole of any substance 50 Copyright © Pearson Education, Inc. , or its affiliates. All Rights Reserved. .