The Mole. Section 10.1 Measuring Matter page SOLUTIONS MANUAL. Practice Problems pages Section 10.1 Assessment page 324 CHAPTER 10

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1 SLUTINS MANUAL The Mole Section 101 Measuring Matter page Practice Problems pages Zinc (Zn) is used to form a corrosion-inhibiting surface on galvanized steel Determine the number of Zn atoms in 250 mol of Zn 250 mol Zn atoms Zn Zn atoms of Zn 2 Calculate the number of molecules in 115 mol of water (H 2 ) 115 mol H molecules H molecules of H 2 3 Silver nitrate (AgN 3 ) is used to make several different silver halides used in photographic films How many formula units of AgN 3 are there in 325 mol AgN 3? 325 mol AgN formula units AgN 3 AgN formula units of AgN 3 4 Challenge Calculate the number of oxygen atoms in 50 mol of oxygen molecules xygen is a diatomic molecule, mol molecules atoms atoms molecule 2 5 How many moles contain each of the following? a atoms Al atoms Al 955 mol Al Al atoms Al b atoms Fe atoms Fe mol Fe Fe atoms Fe 6 Challenge Identify the representative particle for each formula and convert the given number of representative particles to moles a C 2 The representative particle is a molecule molecules C mol C molecules C 2 b ZnCl 2 The representative particle is a formula unit formula units ZnCl 2 ZnCl formula units ZnCl mol ZnCl 2 Section 101 Assessment page Explain why chemists use the mole Chemists use the mole because it is a convenient way of knowing how many representative particles are in a sample 8 State the mathematical relationship between Avogadro s number and ne mole contains representative particles 9 List the conversion factors used to convert between particles and moles representative particles, 1mol representative particles Solutions Manual Chemistry: Matter and Change Chapter

2 SLUTINS MANUAL 10 Explain how a mole is similar to a dozen The mole is a unit for counting representative particles The dozen is used to count 12 items 11 Apply How does a chemist count the number of particles in a given number of moles of a substance? They multiply the number moles by Avogadro s number 14 Arrange these three samples from smallest to largest in terms of number of representative particles: atoms of zinc (Zn), 356 mol of iron (Fe), and molecules of glucose (C 6 H 12 6 ) 356 mol Fe atoms Fe Fe atoms Fe From smallest to largest: molecules glucose, atoms Fe, atoms Zn 12 Calculate the mass in atomic mass units of 025 mol of carbon-12 atoms 025 mol carbon carbon-12 atoms carbon amu 1 carbon-12 atom amu 13 Calculate the number of representative particles of each substance a 115 mol Ag 115 mol Ag atoms Ag Ag atoms Ag b 180 mol H mol H molecules H molecules H 2 c 0150 mol NaCl 0150 mol NaCl formula units NaCl NaCl formula units NaCl d mol CCH mol CCH molecules CCH 4 CH ecules CCH 4 Section 102 Mass and the Mole page Problem-Solving Lab page 326 Hydrogen - 1 Helium Apply What is the mass in grams of one helium atom? (The mass of a neutron is approximately the same as the mass of a proton) Because neutrons and protons have about the same mass, treat the two neutrons and two protons in the He atom as four protons g 4 protons 1 proton He atom g/he atom 2 Draw Carbon-12 contains six protons and six neutrons Draw the carbon-12 nucleus and calculate the mass of one atom in amu and g A correctly drawn model of the nucleus will have six protons and six neutrons packed in a tight spherical shape Because neutrons and protons have about the same mass, treat the six neutrons and six protons in the C-12 atom as 12 protons g 12 protons 1 proton C-12 atom g/c-12 atom 162 Chemistry: Matter and Change Chapter 10 Solutions Manual

3 SLUTINS MANUAL 3 Apply How many atoms of hydrogen-1 are in a 1007-g sample? Recall that 1007 amu is the mass of one atom of hydrogen-1 Round your answer to two significant digits 1 H-1 atom 1007 g g H-1 atoms 4 Apply If you had samples of helium and carbon that contained the same number of atoms as you calculated in Question 1, what would be the mass in grams of each sample? He: He atoms g He atom 403 g C: C atoms g C atom 121 g 5 Conclude What can you conclude about the relationship between the number of atoms and the mass of each sample? The mass of one mole of any atom is the same value in grams as the mass of one atom in amu Practice Problems pages Determine the mass in grams of each of the following a 357 mol Al 357 mol Al b 426 mol Si 426 mol Si 2698 g Al 963 g Al Al 2809 g Si g Si Si 16 Challenge Convert each given quantity in scientific notation to mass in grams expressed in scientific notation a mol Co mol Co g Co 5893 g Co o b mol Zn g Zn mol Zn 160 g Zn Zn 17 Determine the number of moles in each of the following a 255 g Ag 255 g Ag b 3000 g S Ag 0236 mol Ag 1079 g Ag 3000 g S S 9355 mol S 3207 g S 18 Challenge Convert each mass to moles Express the answer in scientific notation a g Zn Zn g Zn 19 Zn 6538 g Zn Zn b 100 kg Fe 1000 g Fe 100 kg Fe Fe 1 kg Fe 5585 g Fe 179 mol Fe Fe 19 How many atoms are in each of the following samples? a 552 g Li Li 552 g Li 694 g Li atoms Li Li atoms Li b 0230 g Pb Pb 0230 g Pb 2072 g Pb atoms Pb Pb atoms Pb c 115 g Hg g 115 g Hg 2006 g Hg atoms Hg g atoms Hg Solutions Manual Chemistry: Matter and Change Chapter

4 SLUTINS MANUAL 20 What is the mass in grams of each of the following? a atoms Bi Bi atoms Bi atoms Bi 2090 g Bi g Bi Bi b atoms Mn Mn atoms Mn atoms 5494 g Mn 913 g Mn Mn c atoms He e atoms He atoms 4003 g He 0226 g He e d atoms N N atoms N atoms 1401 g N N g N Section 102 Assessment page Summarize in terms of particles and mass, one-mole quantities of two different monatomic elements Each one-mole quantity has particles (atoms), but they will have different masses 23 State the conversion factors needed to convert between mass and moles of the element fluorine Mass-to-mole conversions use the conversion factor /18998 g Moles-to-mass conversions use the conversion factor g/ 24 Explain how molar mass relates the mass of an atom to the mass of a mole of atoms Molar mass is the mass in grams of one mole of any pure substance 25 Describe the steps used to convert the mass of an element to the number of atoms of the element Multiply the mass by the inverse of molar mass, and then multiply by Avogadro s number e atoms U U atoms U atoms 2380 g U U g U 21 Challenge Convert each given mass to number of representative particles Identify the type of representative particle, and express the number in scientific notation a g Si Si g Si 2809 g Si atoms atoms Si b 0120 kg Ti 1000 g Ti 0120 kg Ti Ti 1 kg Ti 4787 g Ti atoms atoms Ti 26 Arrange these quantities from smallest to largest in terms of mass: 10 mol of Ar, atoms of Ne, and 20 g of Kr 3995 g Ar 10 mol Ar 3995 g Ar Ar Ne atoms Ne atoms 2018 g Ne 101 g Ne Ne 20 g Kr, 10 mol Ar, atoms Ne 27 Identify the quantity calculated by dividing the molar mass of an element by Avogadro s number Because the molar mass is a ratio of grams per mole and Avogadro s number is a ratio of particles per mole, dividing the molar mass of an element by Avogadro s number yields the mass of a single representative particle of that element 164 Chemistry: Matter and Change Chapter 10 Solutions Manual

5 SLUTINS MANUAL 28 Design a concept map that shows the conversion factors needed to convert among mass, moles, and number of particles 1 Moles Mass Number of particles 4 Moles 2 3 Student concept maps will vary, but should show the correct sets of conversion factors needed to convert among mass, moles, and number of particles Section 103 Moles of Compounds pages Practice Problems pages Zinc chloride (ZnCl 2 ) is used in soldering flux, an alloy used to join two metals together Determine the moles of Cl ions in 250 mol ZnCl 2 2 mol Cl 250 mol ZnCl mol Cl ZnCl 2 30 Plants and animals depend on glucose (C 6 H 12 6 ) as an energy source Calculate the number of moles of each element in 125 mol C 6 H mol C 6 H mol C 750 mol C 6 H mol H 125 mol C 6 H mol H 6 H mol 125 mol C 6 H mol 6 H Iron(III) sulfate [Fe 2 (S 4 ) 3 ] is sometimes used in the water purification process Determine the number of moles of sulfate ions present in 300 mol of Fe 2 (S 4 ) mol Fe 2 (S 4 ) mol S mol S 2 4 Fe 2 (S 4 ) 3 32 How many moles of oxygen atoms are present in 500 mol diphosphorus pentoxide (P 2 5 )? 5 mol 500 mol P mol P Challenge Calculate the number of moles of hydrogen atoms in of water Express the answer in scientific notation mol H mol H mol H Determine the molar mass of each ionic compound a NaH Na 2299 g Na 2299 g Na Na 1600 g 1600 g 1008 g H 1008 g H molar mass NaH 4000 g/mol b CaCl 2 a 4008 g Ca 4008 g Ca a 3545 g Cl 2 mol Cl 7090 g Cl l molar mass CaCl g/mol c KC 2 H 3 2 K 3910 g K 3910 g K K 2 mol C 1201 g C 2402 g C 3 mol H 1008 g H 3024 g H 2 mol 1600 g 3200 g molar mass KC 2 H g/mol Solutions Manual Chemistry: Matter and Change Chapter

6 SLUTINS MANUAL 35 Calculate the molar mass of each molecular compound a C 2 H 2 mol C 1201 g C 2402 g C 6 mol H 1008 g H 6048 g H 1600 g 1600 g molar mass C 2 H 4607 g/mol b HCN 1008 g H 1008 g H 1201 g C 1201 g C N 1401 g N 1401 g N N molar mass HCN 2703 g/mol c CCl g C 1201 g C 3545 g Cl 4 mol Cl g Cl l molar mass CCl g/mol 36 Challenge Identify each substance as a molecular compound or an ionic compound, and then calculate its molar mass a Sr(N 3 ) 2 ionic compound; 8762 g Sr Sr 8762 g Sr Sr 2 mol N 1401 g N 2802 g N N 6 mol 1600 g 9600 g molar mass Sr(N 3 ) g/mol b (NH 4 ) 3 P 4 ionic compound; 3 mol N 1401 g N 4203 g N N 12 mol H 1008 g H g H P 3097 g P 3097 g P P 4 mol 1600 g 6400 g molar mass (NH 4 ) 3 P g/mol c C 12 H molecular compound; 12 mol C 1201 g C g C 22 mol H 1008 g H g H g g molar mass C 12 H g/mol 37 The United States chemical industry produces more sulfuric acid (H 2 S 4 ) in terms of mass, than any other chemical What is the mass of 325 mol of H 2 S 4? Step 1: Find the molar mass of H 2 S 4 2 mol H 1008 g H 2016 g H S 3207 g S 3207 g S S 4 mol 1600 g 6400 g molar mass H 2 S g/mol Step 2: Make mole 0 mass conversion 325 mol H 2 S g H 2 S g H 2 S 2 S Chemistry: Matter and Change Chapter 10 Solutions Manual

7 SLUTINS MANUAL 38 What is the mass of moles of zinc chloride (ZnCl 2 )? Step 1: Find the molar mass of ZnCl g Zn Zn 6538 g Zn Zn 3545 g Cl 2 mol Cl 7090 g Cl l molar mass ZnCl g/mol Step 2: Make mole 0 mass conversion mol ZnCl g ZnCl 2 ZnCl g ZnCl 2 39 Challenge Write the chemical formula for potassium permanganate, and then calculate the mass in grams of 255 mol of the compound Potassium permanganate has a formula of KMn 4 Step 1: Find the molar mass of KMn 4 K 3910 g K 3910 g K K 5494 g Mn Mn 5494 g Mn Mn 4 mol 1600 g 6400 g molar mass KMn g/mol Step 2: Make mole 0 mass conversion 255 mol KMn g Kmn 4 Kmn g KMn 4 40 Determine the number of moles present in each compound a 226 g AgN 3 Step 1: Find the molar mass of AgN g Ag Ag 1079 g Ag Ag N 1401 g N 1401 g N N 3 mol 1600 g 4800 g molar mass AgN g/mol Step 2: Make mass 0 mole conversion 226 g AgN 3 AgN g AgN mol AgN 3 b 650 g ZnS 4 Step 1: Find the molar mass of ZnS g Zn Zn 6539 g Zn Zn S 3207 g S 3207 g S S 4 mol 1600 g 6400 g molar mass ZnS g/mol Step 2: Make mass 0 mole conversion ZnS g ZnS g ZnS mol ZnS 4 c 350 g HCl Step 1: Find the molar mass of HCl 1008 g H 1008 g H 3545 g Cl l 3545 g Cl l molar mass HCl 3646 g/mol Step 2: Make mass 0 mole conversion Cl 350 g HCl 0960 mol HCl 3646 g HCl Solutions Manual Chemistry: Matter and Change Chapter

8 SLUTINS MANUAL 41 Challenge Identify each as an ionic or molecular compound and convert the given mass to moles Express your answers in scientific notation a 250 kg Fe 2 3 ionic compound; Step 1: Find the molar mass of Fe g Fe 2 mol Fe g Fe Fe 3 mol 1600 g 4800 g molar mass Fe g/mol Step 2: Make mass 0 mole conversion 250 kg Fe g 1 kg Fe g Fe mol Fe Fe 2 3 b 254 mg PbCl 4 ionic compound; Step 1: Find the molar mass of PbCl g Pb Pb 2072 g Pb Pb 3545 g Cl 4 mol Cl g Cl l molar mass PbCl g/mol Step 2: Make mass 0 mole conversion 1 g 254 mg PbCl mg PbCl g PbCl mol PbCl 4 42 Ethanol (C 2 H), a domestically produced fuel source, is often blended with gasoline A sample of ethanol has a mass of 456 g a How many carbon atoms does the sample contain? Step 1: Find the molar mass of C 2 H 2 mol C 1201 g C 2402 g 6 mol H 1008 g H 6048 g 1600 g 1600 g molar mass C 2 H 4607 g/mol Step 2: Make mass 0 mole conversion 2 H 456 g C 2 H 4607 g C 2 H 0990 mol C 2 H Step 3: Make mole 0 molecule conversion 0990 mol C 2 H molecules molecules C 2 H Step 4: Determine the number of carbon atoms molecules C 2 H 2 C atoms ecule C 2 H C atoms b How many hydrogen atoms are present? molecules C 2 H 6 H atoms ecule C 2 H H atoms c How many oxygen atoms are present? molecules C 2 H 1 atoms ecule C 2 H atoms 43 A sample of sodium sulfite (Na 2 S 3 ) has a mass of 225 g a How many Na ions are present? Step 1: Find the molar mass of Na 2 S g Na 2 mol Na 4598 g Na S 3207 g S 3207 g S 3 mol 1600 g 4800 g molar mass Na 2 S g/mol Step 2: Make mass 0 mole conversion Na 2 S g Na 2 S g Na 2 S mol Na 2 S 3 Step 3: Make mole 0 formula unit conversion mol Na 2 S formula units 168 Chemistry: Matter and Change Chapter 10 Solutions Manual

9 SLUTINS MANUAL formula units Na 2 S 3 Step 4: Determine the number of Na ions formula units Na 2 S 3 2 Na ions Na ions 1 formula unit Na 2 S 3 b How many S 3 2 ions are present? formula units Na 2 S 3 2 S 3 2 ions 1 formula unit Na 2 S S 3 2 ions c What is the mass in grams of one formula unit of Na 2 S 3? g Na 2 S 3 Na 2 S 3 Na 2 S formula units g Na 2 S 3 /formula unit b How many oxygen atoms are present? atoms molecules C 2 ecule C atoms c What is the mass in grams of one molecule of C 2? 4401 g C molecules g C 2 /molecule 45 What mass of sodium chloride (NaCl) contains formula units? Step 1: Find the number of moles of NaCl formula units NaCl NaCl 762 mol NaCl formula units 44 A sample of carbon dioxide (C 2 ) has a mass of 520 g a How many carbon atoms are present? Step 1: Find the molar mass of C g C 1201 g 2 mol 1600 g 3200 g molar mass C g/mol Step 2: Make mass 0 mole conversion 520 g C mol C 4401 g C 2 2 Step 3: Make mole 0 molecule conversion 118 mol C molecules molecules C 2 Step 4: Determine the number of carbon atoms C atom molecules C 2 ecule C C atoms Step 2: Find the molar mass of NaCl 2299 g Na Na 2299 g Na 3545 g Cl l 3545 g l molar mass NaCl 5844 g/mol Step 3: Make mole 0 mass conversion 5844 g NaCl 762 mol NaCl 445 g NaCl NaCl 46 Challenge A sample of silver chromate has a mass of 258 g a Write the formula for silver chromate The formula for silver chromate is Ag 2 Cr 4 b How many cations are present in the sample? Step 1: Find the molar mass of Ag 2 Cr g Ag 2 mol Ag 2158 g Ag 5200 g Cr r 5200 g r 4 mol 1600 g 6400 g molar mass Ag 2 Cr g/mol Solutions Manual Chemistry: Matter and Change Chapter

10 SLUTINS MANUAL Step 2: Make mass 0 mole conversion 258 g Ag 2 Cr 4 Ag 2 Cr g Ag 2 Cr mol Ag 2 Cr 4 Step 3: Make mole 0 formula unit conversion mol Ag 2 Cr formula units formula units Ag 2 Cr 4 Step 4: Determine the number of cations (Ag ions): formula units Ag 2 Cr 4 2 Ag ions Ag ions 1 formula unit Ag 2 Cr 4 c How many anions are present in the sample? The anions are Cr 4 2 ions: formula units Ag 2 Cr 4 1 Cr 2 4 ions 1 formula unit Ag 2 Cr 4 49 Explain how you can determine the number of atoms or ions in a given mass of a compound Convert the mass to moles, multiply the number of moles by the ratio of the number of atoms or ions to one mole, multiply by Avogadro s number 50 Apply How many moles of K, C, and atoms are there in of K 2 C 2 4? 2 mol K, 2 mol C, 4 mol 51 Calculate the molar mass of MgBr 2 molar mass MgBr g/mol 2(79904 g/ mol) g/mol 52 Calculate Calcium carbonate is the calcium source for many vitamin tablets The recommended daily allowance of calcium is 1000 mg of Ca 2 ions How many moles of Ca 2 does 1000 mg represent? 1000 mg Ca 2 1 g Ca 2 a mg Ca g Ca mol Ca Cr 4 2 ions d What is the mass in grams of one formula unit of silver chromate? 3318 g Ag 2 Cr 4 Ag 2 Cr 4 Ag 2 Cr formula units g Ag 2 Cr 4 /formula unit Section 103 Assessment page Describe how to determine the molar mass of a compound Multiply the mass of one mole of each element by the ratio of that element to one mole of the compound Add the resulting masses 48 Identify the conversion factors needed to convert between the number of moles and the mass of a compound Number of grams, number of grams 53 Design a bar graph that will show the number of moles of each element present in 500 g of a particular form of dioxin (C 12 H 4 C l4 2 ), a powerful poison Number of moles Moles of Elements in 500 g Dioxin C H Cl Element 12 mol C 1201 g C g C 4 mol H 1008 g H 4032 g H 3545 g Cl 4 mol Cl g Cl l 170 Chemistry: Matter and Change Chapter 10 Solutions Manual

11 SLUTINS MANUAL 2 mol 1600 g 3200 g molar mass g/mol 12 H 4 Cl g C 12 H 4 Cl g C 12 H 4 Cl mol C 12 H 4 Cl 4 2 Student bar graphs should show the following molar quantities: 2 mol C 12 H 4 Cl mol C 24 mol C 12 H 4 Cl mol H 2 mol C 12 H 4 Cl mol H 12 H 4 Cl mol Cl 2 mol C 12 H 4 Cl mol Cl 12 H 4 Cl mol 2 mol C 12 H 4 Cl mol 12 H 4 Cl 4 2 Section 104 Emperical and Molecular Formulas pages Practice Problems pages What is the percent composition of phosphoric acid (H 3 P 4 )? Steps 1 and 2: Assume e; calculate molar mass of H 3 P 4 3 mol H 1008 g H 3024 g H P 3097 g P 3097 g P P 4 mol 1600 g 6400 g molar mass H 3 P g/mol Step 3: Determine percent by mass of each element percent H 3024 g H % H 9799 g H 3 P g P percent P % P 9799 g H 3 P g percent % 9799 g H 3 P 4 55 Which has the larger percent by mass of sulfur, H 2 S 3 or H 2 S 2 8? Steps 1 and 2: Assume e; calculate molar mass of H 2 S 3 2 mol H 1008 g H 2016 g H S 3206 g S 3206 g S S 3 mol 1600 g 4800 g molar mass H 2 S g/mol Step 3: Determine percent by mass of S 3206 g S percent S % S 8208 g H 2 S 3 Repeat steps 1 and 2 for H 2 S 2 8 Assume e; calculate molar mass of H 2 S mol H 1008 g H 2016 g 2 mol S 3206 g S 6412 g S 8 mol 1600 g g molar mass H 2 S g/mol Step 3: Determine percent by mass of S 6412 g S percent S g H 2 S % S H 2 S 3 has a larger percent by mass of S 56 Calcium chloride (CaCl 2 ) is sometimes used as a de-icer Calculate the percent by mass of each element in CaCl 2 Steps 1 and 2: Assume e; calculate molar mass of CaCl g Ca a 4008 g Ca a 3545 g Cl 2 mol Cl 7090 g Cl l molar mass CaCl g/mol Solutions Manual Chemistry: Matter and Change Chapter

12 SLUTINS MANUAL Step 3: Determine percent by mass of each element 4008 g Ca percent Ca g CaCl % Ca 7090 g Cl percent Cl g CaCl % Cl 58 The circle graph at the right gives the percent composition for a blue solid What is the empirical formula for this solid? 6316% N 3684% 57 Challenge Sodium sulfate is used in the manufacture of detergents a Identify each of the component elements of sodium sulfate, and write the compound s chemical formula sodium, sulfur, and oxygen; Na 2 S 4 b Identify the compound as ionic or covalent ionic c Calculate the percent by mass of each element in sodium sulfate Steps 1 and 2: Assume e; calculate molar mass of Na 2 S g Na 2 mol Na g Na Na S 3207 g S S 3207 g S 4 mol 1600 g 6400 g molar mass Na 2 S g/mol Step 3: Determine percent by mass of each element 4598 g Na percent Na g NaS % Na 3207 g S percent S g NaS % S 6400 g percent g NaS % Step 1: Assume 100 g sample; calculate moles of each element 3684 g N N 2630 mol N 1401 g N 6316 g 3948 mol 1600 g Step 2: Calculate mole ratios 2630 mol N 1000 mol N N 2630 mol N 1000 mol N N 3948 mol 1500 mol 15 mol 2630 mol 1000 mol N N The simplest ratio is N: 15 mol Step 3: Convert decimal fraction to whole number In this case, multiply by 2 because Therefore, the empirical formula is N Determine the empirical formula for a compound that contains 3598% aluminum and 6402% sulfur Step 1: Assume 100 g sample; calculate moles of each element Al 3598 g Al 1334 mol Al 2698 g Al 6402 g S S 1996 mol S 3206 g S Step 2: Calculate mole ratios 1334 mol Al 1000 mol Al Al 1334 mol Al 1000 mol Al Al 1996 mol S 1500 mol S 15 mol S 1334 mol Al 1000 mol Al Al 172 Chemistry: Matter and Change Chapter 10 Solutions Manual

13 SLUTINS MANUAL The simplest ratio is Al: 15 mol S Step 3: Convert decimal fraction to whole number In this case, multiply by 2 because Therefore, the empirical formula is Al 2 S 3 60 Propane is a hydrocarbon, a compound composed only of carbon and hydrogen It is 8182% carbon and 1818% hydrogen What is the empirical formula? Step 1: Assume 100 g sample; calculate moles of each element 8182 g C 6813 mol C 1201 g C 1818 g H 1804 mol H 1008 g H Step 2: Calculate mole ratios 6183 mol C 1000 mol C 6183 mol C 1000 mol C 1804 mol H 2649 mol H 265 mol H 6183 mol C 1000 mol C The simplest ratio is : 265 mol H Step 3: Convert decimal fraction to whole number In this case, multiply by 3 because Therefore, the empirical formula is C 3 H 8 61 Challenge Aspirin is the world s most-often used medication The chemical analysis of aspirin indicates that the molecule is 6000% carbon, 444% hydrogen, and 3556% oxygen Determine the empirical formula for aspirin Step 1: Assume 100 g sample; calculate moles of each element 6000 g C 500 mol C 1201 g C 444 g H 440 mol H 1008 g H 3556 g 222 mol 1600 g Step 2: Calculate mole ratios 500 mol C 225 mol C 225 mol C 222 mol 100 mol 440 mol C 222 mol 198 mol H 100 mol 2 mol H 222 mol 100 mol 222 mol 100 mol The simplest ratio is 225 mol C: 2 mol H: Step 3: Convert decimal fraction to whole number In this case, multiply by 4 because Therefore, the empirical formula is C 9 H A compound was found to contain 4998 g of carbon and 1047 g of hydrogen The molar mass of the compound is 5812 g/mol Determine the molecular formula Step 1: Assume 100 g sample; calculate moles of each element 4998 g C 4162 mol C 1201 g C 1047 g H 1039 mol H 1008 g H Step 2: Calculate mole ratios 4162 mol C 1000 mol C 4162 mol C 1000 mol C 1039 mol H 250 mol H 25 mol H 4162 mol C 1000 mol C The simplest ratio is : 25 mol H Because , the empirical formula is C 2 Step 3: Calculate the molar mass of the empirical formula 2 mol C 1201 g C 2402 g 5 mol H 1008 g H 5040 g molar mass C g/mol Step 4: Determine whole number multiplier 5812 g/mol 2906 g/mol 2000 The molecular formula is C 4 H 10 Solutions Manual Chemistry: Matter and Change Chapter

14 SLUTINS MANUAL 63 A colorless liquid composed of 4668% nitrogen and 5332% oxygen has a molar mass of 6001 g/mol What is the molecular formula? Step 1: Assume 100 g sample; calculate moles of each element 4668 g N N 3332 mol N 1401 g N 5332 g 3333 mol 1600 g Step 2: Calculate mole ratios 3332 mol N 1000 mol N N 3332 mol N 1000 mol N N 3333 mol 1000 mol 3332 mol N 1000 mol N N The simplest ratio is N: The empirical formula is N Step 3: Calculate the molar mass of the empirical formula N 1401 g N 1401 g N 1600 g 1600 g molar mass N 3001 g/mol Step 4: Determine whole number multiplier 6001 g/mol g/mol The molecular formula is N When an oxide of potassium is decomposed, 1955 g K and 400 g are obtained What is the empirical formula for the compound? Step 1: Calculate moles of each element 1955 g K K mol K 3910 g K 400 g 0250 mol 1600 g Step 2: Calculate mole ratios mol K 200 mol K 2 mol K 0250 mol 100 mol 0250 mol 100 mol 0250 mol 100 mol The simplest ratio is 2 mol K: The empirical formula is K 2 65 Challenge Analysis of a chemical used in photographic developing fluid yielded the percent composition data shown in the circle graph to the right If the chemical s molar mass is 1100 g/mol, what is its molecular formula? C 6545% 2909% H 545% Step 1: Assume 100 g sample; calculate moles of each element 6545 g C 5450 mol C 1204 g C 545 g H g H 2909 g 1818 mol 1600 g Step 2: Calculate mole ratios 5450 mol C 3000 mol C 3 mol C 1818 mol 1000 mol mol H 3 mol H 1818 mol 100 mol 1818 mol 1000 mol 1818 mol 1000 mol The empirical formula is C 3 H 3 Step 3: Calculate the molar mass of the empirical formula 3 mol C 1201 g C 3603 g C 3 mol H 1008 g H 3024 g H 1600 g 1600 g molar mass C 3 H g/mol Step 4: Determine whole number multiplier 1100 g/mol 1998, or gnik The molecular formula is C 6 H Chemistry: Matter and Change Chapter 10 Solutions Manual

15 SLUTINS MANUAL 66 Challenge Analysis of the pain reliever morphine yielded the data shown in the table Determine the empirical formula of morphine Element Mass (g) carbon hydrogen 1680 oxygen 4225 nitrogen 1228 Step 1: Calculate moles of each element g C 1490 mol C 1201 g C 1680 g H 1667 mol H 1008 g H 4225 g g 1228 g N N mol N 1401 g N Step 2: Calculate mole ratios mol N 1000 mol N N mol N 1000 mol N N 1490 mol C 1700 mol C 17 mol C mol N 1000 mol N N 1667 mol H 1902 mol H 19 mol H mol N 1000 mol N N mol 3 mol mol N 1000 mol N N The simplest ratio is 17 mol C: 19 mol H: 3 mol : N The empirical formula is C 17 H 19 3 N Section 104 Assessment page Assess A classmate tells you that experimental data shows a compound s molecular formula to be 25 times its empirical formula Is he correct? Explain No, he is in error because the molecular formula must be a whole-number multiple of the empirical formula 68 Calculate Analysis of a compound composed of iron and oxygen yields g of Fe and 7514 g of What is the empirical formula for this compound? Step 1: Calculate moles of each element Fe g Fe 313 Fe 5585 g Fe 7514 g 4696 mol 1600 g Step 2: Calculate mole ratios 313 Fe 1000 mol Fe Fe 313 Fe 1000 mol Fe Fe 4696 mol 1500 mol 15 mol 313 Fe 1000 mol Fe Fe The simplest ratio is Fe: 15 mol Because , the empirical formula is Fe Calculate An oxide of aluminum contains 0545 g of Al and 0485 g of Find the empirical formula for the oxide Step 1: Calculate moles of each element Al 0545 g Al mol Al 2698 g Al 0485 g mol 1600 g Step 2: Calculate mole ratios mol Al 100 mol Al Al mol Al 100 mol Al Al mol 150 mol 15 mol mol Al 100 mol Al Al The simplest ratio is Al: 15 mol Because , the empirical formula is Al Explain how percent composition data for a compound are related to the masses of the elements in the compound Percent composition is numerically equal to the mass in grams of each element in a 1000-g sample Solutions Manual Chemistry: Matter and Change Chapter

16 SLUTINS MANUAL 71 Explain how you can find the mole ratio in a chemical compound The mole ratio is determined by calculating the moles of each element in the compound and dividing each number of moles by the smallest number of moles It is sometimes necessary to multiply the ratio by an integer to obtain whole numbers 72 Apply The molar mass of a compound is twice that of its empirical formula How are the compound s molecular and empirical formulas related? The molecular formula is equal to twice the empirical formula Section 105 Formulas of Hydrates pages Practice Problems pages The composition of a hydrate is given in the pie chart shown at the right What is the formula and name for this hydrate? MgS 4 488% H 2 512% 73 Analyze Hematite (Fe 2 3 ) and magnetite (Fe 3 4 ) are two ores used as sources of iron Which ore provides the greater percent of iron per kilogram? 5585 g Fe 2 mol Fe g Fe Fe 3 mol 1600 g 4800 g molar mass Fe g/mol 5585 g Fe 3 mol Fe g Fe Fe 4 mol 1600 g 6400 g molar mass Fe g/mol g Fe percent by mass g Fe % Fe in Fe g Fe percent by mass g Fe % Fe in Fe 3 4 Hematite is 6994% Fe, magnetite is 7236% Fe Magnetite contains a greater percentage of iron per kilogram than hematite Step 1: Assume 100 g sample; calculate moles of each component Mg S g MgS g MgS mol MgS g H g H mol H 2 Step 2: Calculate mole ratios 0405 mol MgS mol MgS mol MgS mol MgS 4 MgS 4 MgS mol H mol MgS mol MgS 4 7 mol H 2 MgS 4 The formula of the hydrate is MgS 4 7H 2 Its name is magnesium sulfate heptahydrate 75 Challenge An 1175-g sample of a common hydrate of cobalt(ii) chloride is heated After heating, mol of anhydrous cobalt chloride remains What is the formula and the name for this hydrate? Step 1: Calculate the mass of CoCl 2 remaining mol CoCl g CoCl g CoCl ocl Chemistry: Matter and Change Chapter 10 Solutions Manual

17 SLUTINS MANUAL Step 2: Calculate the mass of water driven off mass of hydrated compound mass of anhydrous compound remaining 1175 g CoCl 2 xh g CoCl g H 2 Step 3: Calculate moles of each component ocl g CoCl g CoCl mol CoCl g H g H mol H 2 Step 4: Calculate mole ratios mol CoCl mol CoCl 2 ocl mol CoCl mol CoCl 2 ocl mol H mol H 2 2 mol H mol CoCl mol CoCl 2 ocl 2 The formula of the hydrate is CoCl 2 2H 2 Its name is cobalt(ii) chloride dihydrate Section 105 Assessment page Summarize the composition of a hydrate A hydrate is a solid ionic compound in which water molecules are trapped 77 Name the compound that has the formula SrCl 2 6H 2 strontium chloride hexahydrate 78 Describe the experimental procedure for determining the formula for a hydrate Explain the reason for each step Mass an empty crucible Add some hydrate and remass Heat the crucible to drive out the water Cool and remass Determine the moles of the anhydrous com pound Subtract the mass of the crucible after heating from the mass of the crucible with the hydrate The difference is the mass of the water lost Determine the moles of water Determine the simplest whole-number ratio of moles of water to moles of anhydrous compound, which will yield the formula of the hydrate 79 Apply A hydrate contains 0050 mol of H 2 to every mol of ionic compound Write a generalized formula for the hydrate XY 5H 2, where XY represents the ionic compound 80 Calculate the mass of the water of hydration if a hydrate loses 0025 mol of H 2 when heated water of hydration 0025 mol H g H g H 2 81 Arrange these hydrates in order of increasing percent water content: MgS 4 7H 2, Ba(H) 2 8H 2, and CoCl 2 6H g Mg Mg 2431 g Mg Mg S 3207 g S 3207 g S S g g 14 mol H 1008 g H g H molar mass MgS 4 7H g Ba Ba g Ba Ba 10 mol 1600 g g 18 mol H 1008 g H g H molar mass Ba(H) 2 8H g 5893 g Co o 5893 g Co o 3545 g Cl 2 mol Cl 7090 g Cl l 6 mol 1600 g 9600 g 12 mol H 1008 g H g H molar mass CoCl 2 6H g 1600 g 1600 g Solutions Manual Chemistry: Matter and Change Chapter

18 SLUTINS MANUAL 2 mol H 1008 g H 2016 g H molar mass H g 7(1802 g H 2 ) g MgS 4 7H % H 2 in MgS 4 7H 2 8(1802 g H 2 ) g Ba(H) 2 8H % H 2 in Ba(H) 2 8H 2 6(1802 g H 2 ) g CoCl 2 6H % H 2 in CoCl 2 6H 2 CoCl 2 6H 2 ; Ba(H) 2 8H 2 ; MgS 4 7H 2 82 Apply Explain how the hydrate in Figure 1017 might be used as a means of roughly determining the probability of rain The hydrate is pink in moist air Everyday Chemistry page How many atoms of potassium does of potassium contain? potassium atoms 85 Compare a mole of Ag-108 and a mole of Pt-195 using atoms, protons, electrons, and neutrons Since they both contain one mole, you have particles of silver and particles of platinum The difference would be in the number of protons, neutrons, and electrons present because silver contains 47 protons per atom, 47 electrons per atom and 61 neutrons per atom, while platinum contains 78 protons per atom, 78 electrons per atom and 117 neutrons per atom A mole of platinum would contain more protons, electrons and neutrons but the same number of atoms 86 Why is the mole an important unit to chemists? A mole allows a chemist to accurately measure the number of atoms, molecules, or formula units in a substance Writing in Chemistry Estimating The estimating process used in this article is sometimes called a back-of-the-envelope calculation Use this method to estimate the total mass of all of the students in your school Suppose a school has a student body of 500 and that the average mass of each student is about 60 kilograms The total mass of the students is calculated as follows 500 students 60 kilograms/student 30,000 kg Chapter 10 Assessment pages Section 101 Mastering Concepts 83 What is the numerical value of Avogadro s number? Currency Examine the information in Table 102 and explain how rolls used to count pennies and dimes are similar to moles Rolled-Coin Values Coin Value of a Roll of Coins Penny $050 Dime $500 ne roll of pennies always contains 50 pennies and one roll of dimes always contains 50 dimes Each roll contains a specific number of coins A mole also contains a specific number of particles, particles 88 Explain how Avogadro s number is used as a conversion factor Avogadro s number is the number of particles in one mole of a substance It can be used to convert particles to moles or moles to particles 178 Chemistry: Matter and Change Chapter 10 Solutions Manual

19 SLUTINS MANUAL 89 Conversion Design a flowchart that could be used to help convert particles to moles or moles to particles Flowcharts will vary but should clearly show the use of proper conversion factors Mastering Problems 90 Determine the number of representative particles in each substance a 0250 mol of silver 0250 mol Ag atoms Ag Ag atoms Ag b mol of sodium chloride mol NaCl formula units NaCl NaCl formula units NaCl c 353 mol of carbon dioxide 353 mol C molecules C molecules C 2 d 0425 mol of nitrogen (N 2 ) 0425 mol N molecules N 2 N molecules N 2 91 Determine the number of representative particles in each substance a 445 mol of C 6 H mol C 6 H molecules molecules C 6 H 12 6 b 0250 mol of KN mol KN formula units formula units KN 3 c 224 mol of H mol H molecules molecules of H 2 d 956 mol of Zn 956 mol Zn atoms atoms of Zn 92 How many molecules are contained in each compound? a 135 mol of carbon disulfide (CS 2 ) 135 mol CS molecules CS 2 S molecules CS 2 b 0254 mol of diarsenic trioxide (As 2 3 ) 0254 mol As molecules As 2 3 As molecules As 2 3 c 125 mol of water 125 mol H molecules H molecules H 2 d 1500 mol of HCl 1500 mol HCl molecules HCl Cl molecules HCl 93 Determine the number of moles in each substance a atoms of lead Pb atoms Pb atoms Pb mol Pb b molecules of glucose molecules glucose glucose molecules glucose 824 mol of glucose c formula units of sodium hydroxide formula units NaH NaH formula units NaH NaH Solutions Manual Chemistry: Matter and Change Chapter

20 SLUTINS MANUAL d copper(ii) ions Cu 2 u ions Cu 2 ions u 2 ions 94 Perform the following conversions a atoms of Si to mol of Si Si atoms Si atoms Si mol Si b mol of H 2 S 4 to molecules of H 2 S mol H 2 S molecules H 2 S 4 2 S molecules H 2 S 4 c formula units of calcium carbonate formula units CaC 3 ac formula units CaC mol CaC 3 96 RDA of Selenium The recommended daily allowance (RDA) of selenium in your diet is mol How many atoms of selenium is this? mol Se atoms Se atoms Se c molecules of CCl 4 to mol of CCl molecules CCl 4 Cl molecules CCl mol CCl 4 d 590 mol of Ca to atoms of Ca 590 mol Ca atoms Ca a atoms Ca 95 How many moles contain the given quantity? a molecules of carbon dioxide molecules C molecules C mol C 2 b formula units of sodium nitrate formula units NaN 3 NaN formula units NaN mol NaN 3 Solution A 0250 mol Cu 2+ ions Solution B 0130 mol Ca 2+ ions 97 The two solutions shown in Figure 1019 are mixed What is the total number of metal ions in the mixture? 0250 mol Ca 2 ions 0130 mol Ca 2 ion 0380 mol metal ions 0380 mol metal ions mol metal ions metal ions Cu 2 and Ca 2 ions 98 Jewelry A bracelet containing 0200 mol metal atoms is 75% gold How many particles of gold atoms are in the bracelet? 0200 mol metal atoms mol Au 0150 mol Au atoms Au Au atoms Au 99 Snowflakes A snowflake contains molecules of water How many moles of water does it contain? molecules H molecules H mol H Chemistry: Matter and Change Chapter 10 Solutions Manual

21 SLUTINS MANUAL 100 If you could count two atoms every second, how long would it take you to count a mole of atoms? Assume that you counted continually for 24 hours every day How does the time you calculated compare with the age of Earth, which is estimated to be years old? s particles 2 particles s h s 1 day 3600 s 24 h 1 y 365 day yr; about 2 million times longer 101 Chlorophyll The green color of leaves is due to the presence of chlorophyll, C 55 H 72 5 N 4 Mg A fresh leaf was found to have mol of chlorophyll per cm 2 How many chlorophyll molecules can be found in 1 cm 2? mol chlorophyll 1 cm molecules chlorophyll chlorophyll molecules/cm 2 Section 102 Mastering Concepts 102 Explain the difference between atomic mass (amu) and molar mass (g) Atomic mass (amu) is the mass of an individual particle (atom, molecule) Molar mass (g) is the mass of a mole of particles 103 Which contains more atoms, a mole of silver atoms or a mole of gold atoms? Explain your answer They both contain the same number of atoms because a mole of anything contains representative particles 104 Which has more mass, a mole of potassium or a mole of sodium? Explain your answer The molar mass of K is g/mol; the molar mass of Na is g/mol Thus, a mole of K has a greater mass 105 Explain how you would convert from number of atoms of a specific element to its mass Convert the number of atoms to moles, then multiply moles by the molar mass of the element 106 Discuss the relationships that exist between the mole, molar mass, and Avogadro s number Molar mass is the mass in grams of one mole of any pure substance Avogadro s number is the number of representative particles in one mole The mass of representative particles of a substance is the molar mass of the substance 107 Barbed Wire Barbed wire is often made of steel, which is primarily iron, and coated with zinc Compare the number of particles and the mass of of each The mole of iron and the mole of zinc both contain particles but a mole of iron has a mass of 5585 g/mol and a mole of zinc has a mass of 6539 g/mol Mastering Problems 108 Calculate the mass of each element a 522 mol of He 400 g He 522 mol He 209 g He e b mol of Ni 5869 g Ni mol Ni 267 g Ni Ni c 222 mol of Ti 4787 g Ti 222 mol Ti 106 g Ti Ti d mol of Ge 7261 g Ge mol Ge 0411 g Ge Ge 109 Perform the following conversions a 350 mol of Li to g of Li 694 g Li 350 mol Li 243 g Li Li Solutions Manual Chemistry: Matter and Change Chapter

22 SLUTINS MANUAL b 765 g of Co to mol of Co o 765 g Co 0130 mol Co 5893 g Co c 562 g of Kr to mol of Kr Kr 562 g Kr 0067 Kr 8380 g Kr d mol of As to g of As 7492 g As mol As 412 g As As 110 Determine the mass in grams of each element a mol of Sb g Sb mol Sb Sb g Sb b mol of Pt g Pt mol Pt Pt g Pt Solutions: 365 mol Mg (2431 g/) 887 g mg 365 mol mg ( atoms/) atoms Mg 2954 g Cr (/5200 g) 0568r 0568r ( atoms/) atoms Cr atoms P ( / atoms) 588 mol P 588 mol P (3097 g/) 1820 g P 0568 mol As (7492 g/) 426 g As 0568 mol As ( atoms/) atom As 112 Convert each to mass in grams a atoms U atoms U U atoms U g U U g U c mol of Ag g Ag mol Ag Ag g Ag d mol of Cr g Cr mol Cr r g Cr 111 Complete Table 103 Mass, Mole, and Particle Data Mass Moles Particles 887 g Mg 2954 g Cr 365 mol Mg 0568 Cr 1820 g P 588 mol P 426 g As 0568 mol As atoms Mg atoms Cr atoms P atoms As b atoms H atoms H 1008 g H 145 g H c atoms atoms 1600 g 0332 g d atoms Pb atoms Pb 2072 g Pb 153 g Pb Pb atoms H atoms Pb atoms Pb 113 Calculate the number of atoms of each element a 258 g of Hg g 258 g Hg g Hg atoms Hg 774 g atoms Hg 182 Chemistry: Matter and Change Chapter 10 Solutions Manual

23 SLUTINS MANUAL b g of Zn Zn g Zn 6359 g Zn atoms Zn Zn atoms Zn c 150 g of Ar Ar 150 g Ar 3995 g Ar atoms Ar Ar atoms Ar d 0124 g of Mg Mg 0124 g Mg 2431 g Mg atoms Mg Mg atoms Mg 114 Arrange from least to most in moles: atoms Ne, 425 mole Ar, atoms Xe, 6596 g Kr Convert atoms Ne, atoms Xe, and g Kr to moles: Ne: atoms Ne Ne 498 mol Ne atoms Ne Xe: atoms Xe Xe 447 mo Xe atoms Xe Kr Kr: 6596 g Kr 0787 Kr 8380 g Kr 0787 Kr < 425 mol Ar < 447 mol Xe < 498 mol Ne 115 Balance Precision A sensitive electronic balance can detect masses of g How many atoms of silver would be in a sample having this mass? Ag g Ag g Ag atoms Ag Ag atoms Ag 116 A sample of a compound contains 386 g of sulfur and 408 g of vanadium How many atoms of sulfur and vanadium does the compound contain? 386 g S 3207 g S atoms S S atoms S 408 g V 5094 g V atoms V V atoms V 117 Which has more atoms, 100 g of C or 100 g of Ca? How many atoms does each have? 100 g C 1201 g C atoms C atoms C a 100 g Ca 4008 g Ca atoms Ca a atoms Ca 100 g C contains more atoms 118 Which has more atoms, 100 mol of C or 100 mol of Ca? How many atoms does each have? ne mole of any substance contains representative particles Thus, 100 moles of carbon and 100 moles of calcium contain the same number or atoms 100 mol atoms atoms 119 A mixture contains 0250 mol of Fe and 120 g of C What is the total number of atoms in the mixture? 0250 mol Fe atoms Fe Fe atoms Fe 120 g C 1201 g C atoms C atoms C atoms Fe atoms C total atoms Solutions Manual Chemistry: Matter and Change Chapter

24 SLUTINS MANUAL 120 Respiration Air contains several gases When resting, every breath you take contains approximately 0600 g of air If argon makes up 0934% of the air, calculate the number of argon atoms inhaled with each breath 0600 g air 0934 g Ar 1 breath 100 g air 3995 g atoms atoms Ar 1 breath Section 103 Mastering Concepts 121 What information is provided by the formula for potassium chromate (K 2 Cr 4 )? ne mole of K 2 Cr 4 contains two moles of K ions and one mole of Cr 4 2 ions 122 In the formula for sodium phosphate (Na 3 P 4 ), how many moles of sodium are represented? How many moles of phosphorus? How many moles of oxygen? 126 List three conversion factors used in molar conversions number of grams, representative particles, representative particles, number of grams 127 Which of these contains the most moles of carbon atoms per mole of the compound: ascorbic acid (C 6 H 8 6 ), glycerin (C 3 H 8 3 ), or vanillin (C 8 H 8 3 )? Explain The formula for vanillin (C 8 H 8 3 ) shows there are eight carbon atoms per molecule, more than ascorbic acid or glycerin Mastering Problems 128 How many moles of oxygen atoms are contained in each compound? 3 mol Na, P, 4 mol 123 Explain how you determine the molar mass of a compound Molar mass is determined by multiplying the molar mass of each element present in the compound by its subscript and then adding these values 124 Insect Repellent Many insect repellents use DEET as the active ingredient DEET was patented in 1946 and is effective against many biting insects What must you know to determine the molar mass of DEET? You must know the chemical formula of the substance to determine the molar mass 125 Why can molar mass be used as a conversion factor? Molar mass is the mass of one mole of a compound It can be used to convert moles of the compound to mass or mass of the compound to moles a 250 mol of KMn 4 4 mol 250 mol KMn 4 KMn 100 mol 4 b 459 mol of C 2 2 mol 459 mol C mol 2 c mol of CuS 4 5H mol CuS 4 5H 2 9 mol 0113 mol us 4 5H How many carbon tetrachloride (CCl 4 ) molecules are in 300 mol of CCl 4? How many carbon atoms? How many chlorine atoms? How many total atoms? 300 mol CCl molecules CCl 4 Cl molecules CCl atoms C molecules CCl 4 ecule CCl atoms C 184 Chemistry: Matter and Change Chapter 10 Solutions Manual

25 SLUTINS MANUAL Atoms per formula unit molecules CCl atoms Cl 4 mol atoms Cl ecule CCl atoms C atoms Cl total atoms The Composition of a Compound Ca C H Atoms 130 The graph in Figure 1020 shows the numbers of atoms of each element in a compound What is the compound s formula? What is its molar mass? CaC 4 H 6 4 : Ca(C 2 H 3 2 ) 2 (calcium acetate) 4008 g Ca a 4008 g Ca a 4 mol C 1201 g C 4804 g C 6 mol H 1008 g H 6048 g H 4 mol 1600 g 6400 g molar mass g/mol 131 Determine the molar mass of each compound a nitric acid (HN 3 ) 1008 g H 1008 g H N 1401 g N 1401 g N N 3 mol 1600 g 4800 g molar mass 6302 g/mol HN 3 b ammonium nitrate (NH 4 N 3 ) 2 mol N 1401 g N 2802 g N N 4 mol H 1008 g H 4032 g H 3 mol 1600 g 4800 g molar mass 8005 g/mol NH 4 N 3 c zinc oxide (Zn) 6539 g Zn Zn 6539 g Zn Zn 1600 g 1600 g molar mass 8139 g/mol Zn d cobalt (II) chloride (CoCl 2 ) 5893 g Co o 5893 g Co o 3545 g Cl 2 mol Cl 7090 g Cl l molar mass g/mol CoCl Garlic Determine the molar mass of allyl sulfide, the compound responsible for the smell of garlic The chemical formula of allyl sulfide is (C 3 ) 2 S 6 mol C 1201 g C 7206 g C 10 mol H 1008 g H g H S 3207 g S 3207 g S S molar mass g/mol (C 3 ) 2 S 133 How many moles are in 1000 g of each compound? a dinitrogen oxide (N 2 ) 2 mol N 1401 g N 2802 g N N 1600 g 1600 g molar mass 4402 g/mol 1000 g N 2 N g N mol N 2 Solutions Manual Chemistry: Matter and Change Chapter

26 SLUTINS MANUAL b methanol (CH 3 H) 1201 g C 1201 g C 4 mol H 1008 g H 4032 g H 1600 g 1600 g molar mass 3204 g/mol 1000 g CH 3 H H 3 H 3204 g CH 3 H 312 mol CH 3 H 134 What is the mass of each compound? 4 mol 1600 g 6400 g molar mass g/mol mol g 848 g benzoyl peroxide 136 Glass Etching Hydrofluoric acid is a substance used to etch glass Determine the mass of HF molecules 1008 g H 1008 g H F 1900 g F 1900 g F F a mol of CuCl g Cu u 6355 g Cu u 3545 g Cl 2 mol Cl 7090 g Cl l molar mass g/mol mol CuCl g CuCl 2 ucl g CuCl 2 b mol of Ca(H) g Ca a 4008 g Ca a 2 mol H 1008 g H 2016 g H 2 mol 1600 g 3200 g molar mass 7410 g/mol mol Ca(H) g Ca(H) 2 a(h) g Ca(H) Acne Benzoyl peroxide (C 14 H 10 4 ) is a substance used as an acne medicine What is the mass in grams of mol C 14 H 10 4? 14 mol C 1201 g C g C 10 mol H 1008 g H g H molar mass g/mol molecules HF F molecules HF 1650 g HF 2001 g HF F 137 What is the mass of a mole of electrons if one electron has a mass of g? electrons g 1 electron g 138 How many moles of ions are in each compound? a g of AgN g Ag Ag g Ag Ag N 1401 g N 1401 g N N 3 mol 1600 g 4800 g molar mass g/mol AgN g AgN g AgN 3 2 mol ions mol ions AgN 3 b 0100 mol of K 2 Cr 4 3 mol ions 0100 mol K 2 Cr K 2 Cr mol ions Chemistry: Matter and Change Chapter 10 Solutions Manual

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