1 Chapter 7 Chemical Quantities The Mole Basic Chemistry Copyright © 2011 Pearson Education, Inc. Collections of items include dozen, gross, and mole.

2 Collection Terms A collection term states a specific number of items. 1 dozen donuts = 12 donuts 1 ream of paper = 500 sheets 1 case = 24 cans Basic Chemistry Copyright © 2011 Pearson Education, Inc. Collections of items include dozen, gross, and mole.

3 A mole (mol) is a collection that contains the same number of particles as there are carbon atoms in g of carbon x atoms of an element (Avogadro’s number). 1 mol of Element Number of Atoms 1 mol C = x C atoms 1 mol Na = x Na atoms 1 mol Au = x Au atoms A Mole of Atoms Basic Chemistry Copyright © 2011 Pearson Education, Inc.

4 A mole of a covalent compound has Avogadro’s number of molecules 1 mol CO 2 = x CO 2 molecules 1 mol H 2 O = x H 2 O molecules of an ionic compound contains Avogadro’s number of formula units 1 mol NaCl = x NaCl formula units 1 mol K 2 SO 4 = x K 2 SO 4 formula units A Mole of A Compound Basic Chemistry Copyright © 2011 Pearson Education, Inc.

5 Samples of One Mole Quantities Basic Chemistry Copyright © 2011 Pearson Education, Inc.

6 Avogadro’s number (6.022 x ) can be written as an equality and two conversion factors. Equality: 1 mol = x particles Conversion Factors: x particles and 1 mol 1 mol x particles Avogadro’s Number Basic Chemistry Copyright © 2011 Pearson Education, Inc.

7 Using Avogadro’s Number Avogadro’s number converts moles of a substance to the number of particles. How many Cu atoms are in 0.50 mol of Cu? 0.50 mol Cu x x Cu atoms 1 mol Cu = 3.0 x Cu atoms Basic Chemistry Copyright © 2011 Pearson Education, Inc.

8 Using Avogadro’s Number Avogadro’s number is used to convert the number of particles of a substance to moles. How many moles of CO 2 are in 2.50 x molecules of CO 2 ? 2.50 x molecules CO 2 x 1 mol CO x molecules CO 2 = 4.15 mol of CO 2 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

9 1. The number of atoms in 2.0 mol of Al is A. 2.0 Al atoms B. 3.0 x Al atoms C. 1.2 x Al atoms 2. The number of moles of S in 1.8 x atoms of S is A. 1.0 mol of S atoms B. 3.0 mol of S atoms C. 1.1 x mol of S atoms Learning Check Basic Chemistry Copyright © 2011 Pearson Education, Inc.

mol Al x x Al atoms 1 mol Al = 1.2 x Al atoms (C) x S atoms x 1 mol S x S atoms = 3.0 mol of S atoms (B) Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

11 Subscripts and Moles The subscripts in a formula state the relationship of atoms in the formula the moles of each element in 1 mol of compound Glucose C 6 H 12 O 6 1 molecule: 6 atoms of C 12 atoms of H 6 atoms of O 1 mol: 6 mol of C 12 mol of H 6 mol of O Basic Chemistry Copyright © 2011 Pearson Education, Inc.

12 Subscripts State Atoms and Moles Basic Chemistry Copyright © 2011 Pearson Education, Inc.

13 Factors from Subscripts Subscripts used for conversion factors relate moles of each element in 1 mol of compound for aspirin C 9 H 8 O 4 can be written as 9 mol C 8 mol H 4 mol O 1 mol C 9 H 8 O 4 1 mol C 9 H 8 O 4 1 mol C 9 H 8 O 4 and 1 mol C 9 H 8 O 4 1 mol C 9 H 8 O 4 1 mol C 9 H 8 O 4 9 mol C 8 mol H 4 mol O Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Calculating Atoms or Molecules 14 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

15 Learning Check How many O atoms are in mol of aspirin, C 9 H 8 O 4 ? Basic Chemistry Copyright © 2011 Pearson Education, Inc.

16 Solution How many O atoms are in mol of aspirin, C 9 H 8 O 4 ? STEP 1 Given mol of C 9 H 8 O 4 Need molecules of C 9 H 8 O 4 STEP 2 Plan moles of aspirin moles of O atoms of O Basic Chemistry Copyright © 2011 Pearson Education, Inc.

17 Solution (continued) STEP 3 Equalities/Conversion Factors 1 mol of C 9 H 8 O 4 = 4 mol of O 1 mol C 9 H 8 O 4 and 4 mol O 4 mol O 1 mol C 9 H 8 O 4 1 mol of O = x atoms of O 1 mole O and x atoms O x atoms O 1 mol O STEP 4 Set Up Problem mol C 9 H 8 O 4 x 4 mol O x x O atoms 1 mol C 9 H 8 O 4 1 mol O = 3.61 x O atoms Basic Chemistry Copyright © 2011 Pearson Education, Inc.

18 Molar Mass Basic Chemistry Copyright © 2011 Pearson Education, Inc. Lithium carbonate produces a red color in fireworks.

19 Molar Mass The molar mass is the mass of one mol of an element or compound is the atomic mass expressed in grams Basic Chemistry Copyright © 2011 Pearson Education, Inc.

20 Molar Mass from the Periodic Table Basic Chemistry Copyright © 2011 Pearson Education, Inc.

21 Give the molar mass for A. 1 mol of K atoms =________ B. 1 mol of Sn atoms =________ Learning Check Basic Chemistry Copyright © 2011 Pearson Education, Inc.

22 Give the molar mass for A. 1 mol of K atoms =39.10 g B.1 mol of Sn atoms =118.7 g Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Guide to Calculating Molar mass 23 Basic Chemistry Copyright © 2011 Pearson Education, Inc.

24 Molar Mass of a Compound For a compound, the molar mass is the sum of the molar masses of the elements in the formula. Example: Calculate the molar mass of CaCl 2. ElementNumber of Moles Atomic MassTotal Mass Ca g/mol g Cl g/mol g CaCl g Basic Chemistry Copyright © 2011 Pearson Education, Inc.

25 Molar Mass of K 3 PO 4 Determine the molar mass of K 3 PO 4. ElementNumber of Moles Atomic MassTotal Mass in K 3 PO 4 K g/mol g P g/mol g O g/mol g K 3 PO g Basic Chemistry Copyright © 2011 Pearson Education, Inc.

26 Some One-Mol Quantities Basic Chemistry Copyright © 2011 Pearson Education, Inc.

27 Calculate the molar mass for Al(OH) 3 with four significant figures. 1) g/mol 2) g/mol 3) g/mol Learning Check Basic Chemistry Copyright © 2011 Pearson Education, Inc.

28 STEP 1 Obtain the molar mass of each element. Al g/mol O g/mol H g/mol STEP 2 Multiply each by the subscript. 1 mol Al x g Al = g 1 mol Al 3 mol O x g O = g 1 mol O 3 mol H x g H = g 1 mol H STEP 3 Calculate the molar mass by adding the masses of the elements. 1 mol of Al(OH) 3 = g (3) Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

29 Prozac, C 17 H 18 F 3 NO, is an antidepressant that inhibits the uptake of serotonin by the brain. What is the molar mass of Prozac? 1) g/mol 2) g/mol 3) g/mol Learning Check Basic Chemistry Copyright © 2011 Pearson Education, Inc.

30 Prozac, C 17 H 18 F 3 NO, is an antidepressant that inhibits the uptake of serotonin by the brain. What is the molar mass of Prozac? STEP 1 Obtain the molar mass of each element. C g/mol H g/mol F g/mol N g/mol O g/mol STEP 2 Multiply each by the subscript in the formula. 17 mol C x g C = g 1 mol C 18 mol H x g H = g 1 mol H Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Solution (continued) STEP 2 3 mol F x g F = g 1 mol F 1 mol N x g N = g 1 mol N 1 mol O x g O = g 1 mol O STEP 3 1 mol of C 17 H 18 F 3 NO = g 31

32 Calculations Using Molar Mass Basic Chemistry Copyright © 2011 Pearson Education, Inc. Table salt is NaCl.

33 Molar mass conversion factors are written from molar mass relate grams and moles of an element or compound Example: Write molar mass factors for methane CH 4 used in gas cook tops and gas heaters. Molar mass: 1 mol CH 4 = g Conversion factors: g CH 4 and 1 mol CH 4 1 mol CH g CH 4 Molar Mass Factors Basic Chemistry Copyright © 2011 Pearson Education, Inc.

34 Acetic acid HC 2 H 3 O 2 gives the sour taste to vinegar. Write an equality and two molar mass conversion factors for acetic acid. Learning Check Basic Chemistry Copyright © 2011 Pearson Education, Inc.

35 Acetic acid HC 2 H 3 O 2 gives the sour taste to vinegar. Write an equality and two molar mass conversion factors for acetic acid. Equality: 1 mol of acetic acid = g of acetic acid Molar mass conversion factors: 1 mol acetic acid and g acetic acid g acetic acid 1 mol acetic acid Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

36 Guide to Calculation Using Molar Mass Basic Chemistry Copyright © 2011 Pearson Education, Inc.

37 Aluminum is used to build lightweight bicycle frames. How many grams of Al are in 3.00 mol of Al? Moles to Grams Basic Chemistry Copyright © 2011 Pearson Education, Inc.

38 STEP 1 Given 3.00 mol of Al Need grams of Al STEP 2 Plan moles of Al grams of Al STEP 3 Equalities/Conversion Factors 1 mol of Al = g of Al 1 mol Al and g Al g Al 1 mol Al Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

39 STEP 4 Set Up Problem Set up with molar mass as a factor: 3.00 mol Al x g Al = 80.9 g of Al 1 mol Al molar mass factor for Al Solution (continued) Basic Chemistry Copyright © 2011 Pearson Education, Inc.

40 The artificial sweetener aspartame (NutraSweet), C 14 H 18 N 2 O 5, is used to sweeten diet foods, coffee, and soft drinks. How many moles of aspartame are present in 225 g of aspartame? Learning Check Basic Chemistry Copyright © 2011 Pearson Education, Inc.

41 STEP 1 Given 225 g of C 14 H 18 N 2 O 5 Need moles STEP 2 Plan g of aspartame moles of aspartame STEP 3 Equalities/Conversion Factors 1 mol aspartame = g 1 mol aspartame and g aspartame g aspartame 1 mol aspartame STEP 4 Set Up Problem 225 g aspartame x 1 mol aspartame g aspartame mole factor (inverted) = mol of aspartame Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

42 Learning Check Allyl sulfide, C 6 H 10 S, is a compound that has the odor of garlic. How many moles of C 6 H 10 S are in 225 g of C 6 H 10 S? Basic Chemistry Copyright © 2011 Pearson Education, Inc.

43 STEP 1 Given 225 g of C 6 H 10 S Need moles of C 6 H 10 S STEP 2 Plan g of C 6 H 10 S moles of C 6 H 10 S STEP 3 Equalities/Conversion Factors 1 mol of C 6 H 10 S = g of C 6 H 10 S 1 mol C 6 H 10 S and g C 6 H 10 S g C 6 H 10 S 1 mol C 6 H 10 S STEP 3 Set Up Problem 225 g C 6 H 10 S x 1 mol C 6 H 10 S g C 6 H 10 S = 1.97 mol C 6 H 10 S Solution Basic Chemistry Copyright © 2011 Pearson Education, Inc.

Guide to Converting Grams to Particles 44

45 Learning Check How many molecules of H 2 O are in 24.0 g of H 2 O? 1) 4.52 x ) 1.44 x ) 8.02 x Basic Chemistry Copyright © 2011 Pearson Education, Inc.

46 Solution STEP 1 Given 24.0 g of H 2 O Need molecules of H 2 O STEP 2 Plan g of H 2 O moles of H 2 O molecules of H 2 O STEP 3 Equalities/Conversion Factors 1 mol of H 2 O = g of H 2 O 1 mol H 2 O and g H 2 O g H 2 O 1 mol H 2 O Basic Chemistry Copyright © 2011 Pearson Education, Inc.

47 Solution (continued) STEP 3 Equalities/Conversion Factors (continued) 1 mol of H 2 O = molecules of H 2 O 1 mol H 2 O and x H 2 O molecules H 2 O molecules 1 mol H 2 O STEP 4 Set Up Problem 24.0 g H 2 O x 1 mol H 2 O g H 2 O x x H 2 O molecules 1 mol H 2 O = 8.02 x H 2 O molecules (3) Basic Chemistry Copyright © 2011 Pearson Education, Inc.