3/17/2017. Avogadro s Number. Collection Terms. A Mole of Atoms. A Mole of A Compound. Samples of One Mole Quantities.

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Chapter 7 Lecture Chapter 7 Chemical Quantities 7.1 The Mole Fifth Edition Collection Terms A collection term states a specific number of items.

Calculate the number of moles of an element in a given number of moles of a compound. 2 Collections of items include dozen, gross, and mole.

1 mol of Element Number of Atoms 1 mol C = 6.022 x 10 23 C atoms 1 mol Na = 6.022 x 10 23 Na atoms 1 mol Au = 6.

1 Chapter 7 Lecture Chapter 7 Chemical Quantities 7.1 The Mole Fifth Edition 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 Learning Goal Use Avogadro s number to calculate the number of particles in a given number of moles. Calculate the number of moles of an element in a given number of moles of a compound. 2 Collections of items include dozen, gross, and mole. A Mole of Atoms 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 A Compound 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 3 4 Samples of One Mole Quantities Avogadro s Number 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 5 6 1

022 x 10 23 Cu atoms 1 mol Cu = 3.0 x 10 23 Cu atoms 2.50 x 10 24 molecules CO 2 x 1 mol CO 2 6.022 x 10 23 molecules CO 2 = 4.15 mol of CO 2 7 8 Sample Problem 7.

2 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? 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? 0.50 mol Cu x x Cu atoms 1 mol Cu = 3.0 x Cu atoms 2.50 x molecules CO 2 x 1 mol CO x molecules CO 2 = 4.15 mol of CO Sample Problem 7.1 Calculating the Number of Molecules How many molecules are present in 1.75 mol of carbon dioxide? 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 10 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 Subscripts State Atoms and Moles 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

Factors from Subscripts Calculating Atoms or Molecules 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

150 mol of aspirin, C 9 H 8 O 4? How many moles of sulfur (S) are in 1.8 10 24 atoms of sulfur? A. 1.0 mol of S B. 3.0 mol of S C. 1.1 10 48 mol of S 15 Chapter 7 Lecture Chapter 7 Chemical Quantities 7.

3 Factors from Subscripts Calculating Atoms or Molecules 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 How many O atoms are in mol of aspirin, C 9 H 8 O 4? How many moles of sulfur (S) are in atoms of sulfur? A. 1.0 mol of S B. 3.0 mol of S C mol of S 15 Chapter 7 Lecture Chapter 7 Chemical Quantities 7.2 Molar Mass Fifth Edition Molar Mass The molar mass is the mass of one mol of an element or compound is the atomic mass expressed in grams Learning Goal Given the chemical formula of a substance, calculate its molar mass. 18 3

Molar Mass from the Periodic Table Give the molar mass for A. 1 mol of K atoms = B.

mass is the sum of the molar masses of the elements in the formula.

08 g/mol 40.08 g Cl 2 35.45 g/mol 70.90 g CaCl 2 110.

4 Molar Mass from the Periodic Table Give the molar mass for A. 1 mol of K atoms = B. 1 mol of Sn atoms = Guide to Calculating Molar mass 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. Element Number of Moles Atomic Mass Total Mass Ca g/mol g Cl g/mol g CaCl g Molar Mass of K 3 PO 4 Some One-Mol Quantities Determine the molar mass of K 3 PO 4. Element Number of Moles Atomic Mass Total Mass in K 3 PO 4 K g/mol g P g/mol g O g/mol g K 3 PO g

Calculate the molar mass for Al(OH) 3 with four significant figures. 1) 44.00 g/mol 2) 75.00 g/mol 3) 78.

4 g/mol 25 26 Chapter 7 Lecture Chapter 7 Chemical Quantities 7.

5 Calculate the molar mass for Al(OH) 3 with four significant figures. 1) g/mol 2) g/mol 3) g/mol 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 Chapter 7 Lecture Chapter 7 Chemical Quantities 7.3 Calculations Using Molar Mass Learning Goal Given the number of moles of a substance, calculate the mass in grams; given the mass, calculate the number of moles. Fifth Edition Molar Mass Factors 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 28 Guide to Calculation Using Molar Mass 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

98 g Al 1 mol Al 31 32 Solution (continued) STEP 4 Set Up Problem Set up with molar mass as a factor: 3.00 mol Al x 26.98 g Al = 80.

6 Moles to Grams Solution Aluminum is used to build lightweight bicycle frames. How many grams of Al are in 3.00 mol of Al? 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 (continued) 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 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? 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? Guide to Converting Grams to Particles

7 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

Chapter 7 Chemical Quantities

Chapter 7 Chemical Quantities The Mole Collections of items include dozen, gross, and mole. 1 Collection Terms A collection term states a specific number of items. 1 dozen donuts = 12 donuts 1 ream of