Chemistry Homework Chapters 7 & 8 PDF

# Homework: Chapters 7 and 8 ## Date: October 3, 2024 ## Chapter 7 - 7.3 Calculate each of the following: a. Number of C atoms in 0.500 mol of C: $0.500 \times 6.022 \times 10^{23} = 3.011 \times 10^{23}$ C atoms b. Number of SO₂ molecules in 1.28 mol of SO₂ $1.28 \times...

# Homework: Chapters 7 and 8 ## Date: October 3, 2024 ## Chapter 7 - 7.3 Calculate each of the following: a. Number of C atoms in 0.500 mol of C: $0.500 \times 6.022 \times 10^{23} = 3.011 \times 10^{23}$ C atoms b. Number of SO₂ molecules in 1.28 mol of SO₂ $1.28 \times 6.022 \times 10^{23} = 7.71 \times 10^{23}$ molecules of SO₂ c. Moles of Fe in 5.22 x 10²² atoms of Fe: $5.22 \times 10^{22} \text{ atoms}/6.022 \times 10^{23} \text{ atoms/mole} = 0.0864$ moles of Fe d. Moles of C₂H₆O in 8.50 x 10²⁴ molecules of C₂H₆O: $8.50 \times 10^{24} \text{ molecules} / 6.022 \times 10^{23} \text{ molecules/mole} = 14.12$ moles of C₂H₆O ## Chapter 7 - 7.5 Calculate each of the following quantities in 2.00 mol of H₃PO₄: a. Moles of H: $(3)(2.00) = 6.00$ mol of H b. Moles of O: $(4)(1.00) = 8.00$ mol of O c. Atoms of P: $(6.022 \times 10^{23} \text{ atoms/mol})(2.00 \text{ mol}) = 1.20 \times 10^{24}$ atoms of P d. Atoms of O: $(6.022 \times 10^{23})(8.00) = (4.82 \times 10^{24}$ atoms of O ## Chapter 7 - 7.7 Quinine, C₂₀H₂₄N₂O₂, is a component of tonic water and bitter lemon. a. How many moles of H are in 1.5 mol of quinine: 36 mol of H b. How many moles of C are in 5.0 mol of quinine? $1.0 \times 10^{2}$ mol of C c. How many moles of N are in 0.020 mol of quinine? 0.040 mol of N ## Chapter 7 - 7.15 Calculate the molar mass for each of the following: a. KCl, salt substitute: $(1 \times 39.10)+(1 \times 35.45) = 39.1 \text{ g/mol} + 35.45 \text{ g/mol} = 74.55\text{g/mol} = (75 \text{g/mol})$ b. Fe₂O₃, rust: $(2 \times 55.85) + (3 \times 16.00) = 111.7 \text{ g/mol} + 48 \text{ g/mol} = 159.7 \text{ g/mol} = (160 \text{g/mol})$ c. C₁₉H₂₀FNO₃, Paxil, antidepressant: $(19 \times 12.01) + (20 \times 1.008) + (1 \times 19.00) + (1 \times 14.01) + (3 \times 16.00) = 228.19 \text{ g/mol} + 20.16 \text{ g/mol} + 19.00\text{ g/mol }+ 14.01\text{ g/mol} + 48.00 \text{ g/mol} = 329.36 \text{ g/mol} = (329 \text{ g/mol})$ ## Chapter 7 - 7.16 Calculate the molar mass for each of the following: a. FeSO₄, Iron Supplement: $(1 \times 55.85) + (1 \times 32.07) + (4 \times 16.00) = 55.85 \text{ g/mol} + 32.07\text{ g/mol} + 64 \text{ g/mol} = 151.92 \text{ g/mol} = (152\text{ g/mol})$ b. Al₂O₃, absorbent and abrasive: $(2 \times 26.98) + (3 \times 16.00) = 53.96 \text{ g/mol} + 48 \text{ g/mol} = 101.96 \text{ g/mol} = (102 \text{g/mol})$ c. C₇H₅NO₃S, Saccharin, artificial sweetener: $(7 \times 12.01) + (5 \times 1.008) + (1 \times 14.01) + (3 \times 16.00) + (1 \times 32.07) = 84.07 \text{ g/mol} + 5.04 \text{ g/mol} + 14.01 \text{ g/mol} + 48 \text{ g/mol} + 32.07 \text{ g/mol} = 183.19 \text{ g/mol} = (183 \text{g/mol})$ ## Chapter 7 - 7.22 Calculate the mass, in grams, for each of the following: a. 5.12 mol of Al: $(5.12 \text{ mol}) (26.98 \text{ g/mol}) = 138.13 \text{ g} = (138 \text{ g})$ b. 0.75 mol of Cu: $(0.75 \text{ mol}) (63.55 \text{ g/mol}) = 47.66 \text{ g} = (48\text{ g})$ c. 3.52 mol of MgBr₂: $(1 \times 24.31) + (2 \times 79.90) = 24.31 \text{ g/mol} + 159.8 \text{ g/mol} = 184.11 \text{ g/mol}$ $(3.52 \text{ mol})(184.11 \text{ g/mol}) = 648.06 \text{ g} = (648.1 \text{ g})$ d. 0.145 mol of C₂H₆O: $(2 \times 12.01) + (6 \times 1.008) + (1 \times 16.00) = 24.02 \text{ g/mol} + 6.04 \text{ g/mol} + 16.00\text{ g/mol} = 46.06 \text{ g/mol}$ $(0.145 \text{ mol})(46.06 \text{ g/mol}) = 6.67 \text{ g} = (7 \text{ g})$ e. 2.08 mol of (NH₄)₂ SO₄: $(2 \times 14.01) + (8 \times 1.008) + (1 \times 32.07) + (4 \times 16.00) = 28.02 \text{ g/mol} + 8.06 \text{ g/mol} + 32.07 \text{ g/mol} + 64 \text{ g/mol} = 132.15 \text{ g/mol}$ $(2.08 \text{ mol}) (132.15 \text{ g/mol}) = 274.87 \text{ g} = (275 \text{g})$ ## Chapter 7 - 7.24 Calculate the mass, in grams, in 2.28 mol of each of the following: a. Pd: $(2.28 \text{ mol})(106.4 \text{ g/mol}) = 242.59 \text{ g} = (243\text{ g})$ b. SO₃: $(1\times 32.07) + (3 \times 16.00) = 32.07 \text{ g/mol} + 48 \text{ g/mol}= 80.07 \text{ g/mol}$ $(80.07 \text{ g/mol}) (2.28 \text{ mol}) = 182.55 \text{ g} = (183\text{ g})$ c. C₃H₆O₃: $(3 \times 12.01) + (6 \times 1.008) + (3 \times 16.00) = 36.03 \text{ g/mol} + 6.04 \text{ g/mol} + 48 \text{ g/mol} = 90.07 \text{ g/mol}$ $(90.03 \text{ g/mol})(2.28 \text{ mol}) = 205.35 \text{ g} = (205.4 \text{ g})$ d. Mg(HCO₃)₂: $(1 \times 24.31) + (2 \times 1.008) + (2 \times 12.01) + (6 \times 16.00) = 24.31 \text{ g/mol} + 2.01 \text{ g/mol} + 24.02 \text{ g/mol} + 96\text{ g/mol} = 146.34 \text{ g/mol}$ $(166.34 \text{ g/mol}) (2.28 \text{ mol}) = 333.65 \text{ g} = (334\text{ g})$ e. SF₆: $(1 x 32.07) + (6 \times 19.00) = 32.07 \text{ g/mol} + 114 \text{ g/mol} = 146.07\text{ g/mol}$ $(146.07 \text{ g/mol})(2.28 \text{ mol})= 333.03 g = (333\text{ g})$ ## Chapter 7 - 7. 27 Calculate the number of moles in 25.0 g of each of the following: a. He: $25.0\text{ g}/4.003 \text{ g/mol} = 6.24 \text{ mol}$ b. O₂: $(2 \times 16.00) = 32 \text{ g/mol}$ $25.0 \text{ g}/32 \text{ g/mol} = 0.78 \text{ mol}$ c. Al(OH)₃: $(1 \times 26.98) + (3 \times 16.00) + (3 \times 1.008) = 26.98 \text{ g/mol} + 48 \text{ g/mol} + 3.02 \text{ g/mol} = 78 \text{ g/mol}$ $25.0 \text{ g}/78 \text{ g/mol} = 0.32 \text{ mol}$ d. Ga₂S₃: $(2 \times 69.72) + (3 \times 32.07) = 139.44 \text{ g/mol} + 96.21 \text{ g/mol} = 235.65 \text{ g/mol}$ $25.0 \text{ g}/235.65 \text{ g/mol} = 0.10 \text{ mol}$ e. C​​₄H₁₀, butane: $(4 \times 12.01) + (10 \times 1.008) = 48.04\text{ g/mol} + 10.08\text{ g/mol} = 58.12 \text{ g/mol}$ $25.0\text{ g}/58.12 \text{ g/mol} = 0.43 \text{ mol}$ ## Chapter 7 - 7.31 Propane gas, C₃H₈, is used as fuel for many barbecues. a. How many moles of H are in 34.0 g of propane? $6.17 \text{ mol of H}$ b. How many grams of C are in 1.50 mol of propane? $54.0 \text{ g of C}$ c. How many grams of C are in 34.0 g of propane? $27.8 \text{ g of C}$ d. How many grams of H are in 0.254 g of propane? $0.0465 \text{ g or } 4.65 \times 10^{-2} \text{ g of H}$ ## Chapter 7 - 7.39 Calculate the molar mass for each of the following: (7.2) a. ZnSO₄, zinc sulfate, zinc supplement: $(1 \times 65.41) + (1 \times 32.07) + (4 \times 16.00) = 65.41 \text{ g/mol} + 32.07 \text{ g/mol} + 64 \text{ g/mol} = 161.48 \text{ g/mol} = (161.5 \text{ g/mol})$ b. Ca(IO₃)₂, calcium iodate, iodine source in table salt: $(1 \times 40.08) + (1 \times 126.9) + (3 \times 16.00) = 40.08 \text{ g/mol} + 126.9 \text{ g/mol} + 48 \text{ g/mol} = 214.98 \text{ g/mol} = (215 \text{ g/mol})$ c. C₅H₈NNaO₄, monosodium glutamate, flavor enhancer: $(5 \times 12.01) + (8 \times 1.008) + ( 1 \times 14.01) + (1 \times 22.99) + (4 \times 16.00) = 60.05\text{ g/mol }+ 8.064\text{ g/mol} + 14.01\text{ g/mol} + 22.99\text{ g/mol} + 64\text{ g/mol} = 169.11 \text{ g/mol}$ d. C₆H₁₂O₂, isoamyl formate, used to make artificial fruit syrups: $( 6 \times 12.01) + (12 \times 1.008) + (2 \times 16.00) = 72.06\text{ g/mol } + 12.09 \text{ g/mol } + 32\text{ g/mol} = 11.15 \text{ g/mol} = (116.2 \text{ g/mol})$ ## Chapter 8 - 8.1 State the number of atoms of oxygen in the reactants and in the products for each of the following equations. a. 3NO₂(g) + H₂O(l) → NO(g) + 2HNO₃(aq) reactants/products: 7 O atoms b. 5C(s) + 2SO₂(g) → CS₂(g) + 4CO(g) reactants/products: 4 O atoms c. 2C₂H₂(g) + 5O₂ (g) → 4CO₂(g) + 2H₂O(g) reactants/products: 10 O atoms d. N₂H₄(g) + 2H₂O₂(g) → N₂(g) + 4H₂O(g) reactants/products: 4 O atoms ## Chapter 8 - 8.4 Determine whether each of the following equations is balanced or not balanced. a. PCl₃(s) + Cl₂(g) → PCl₅(s) Balanced b. CO(g) + 2H₂(g) → CH₄O(g) Balanced c. 2KClO₃(s) → 2KCl(s) + O₂(g) Not balanced d. Mg(s) + N₂(g) → Mg₃N₂(s) Balanced ## Chapter 8 - 8.6 All of the following are balanced equations. State the number of atoms of each element in the reactants and in the products: a. 2N₂(g) + 3O₂(g) → 2N₂O₃(g) Reactants: 4 nitrogen atoms and 6 oxygen atoms. Products: 4 nitrogen atoms and 6 oxygen atoms. b. Al₂O₃(s) + 6HCl(aq) → 3H₂O(l) + 2AlCl₃(aq) Reactants: 2 aluminum atoms, 3 oxygen atoms, 6 hydrogen atoms, and 6 chloride atoms Products: 2 aluminum, 3 oxygen, 6 hydrogen, and 6 chloride. c. C₅H₁₂(l) + 8O₂(g) → 5CO₂(g) + 6H₂O(g) Reactants: 5 carbon, 12 hydrogen, and 16 oxygen Products: 5 carbon, 12 hydrogen, and 16 oxygen. ## Chapter 8 - 8.7 Balance each of the following chemical equations: a) N₂(g) + O₂(g) → NO(g) N₂(g) + O₂(g) → 2NO(g) b) HgO(s) → Hg(l) + O₂(g) 2HgO(s) → 2Hg(l) + O₂(g) c) Fe(s) + O₂(g) → Fe₂O₃(s) 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s) d) Na(s) + Cl₂(g) → NaCl(s) 2Na(s) + Cl₂(g) → 2NaCl(s) e) Cu₂O(s) + O₂(g) → CuO(s) 2Cu₂ O(s) + O₂(g) → 4CuO(s) ## Chapter 8 - 8.8 Balance each of the following chemical equations: a) Ca(s) + Br₂(l) → CaBr₂(s) Ca(s) + Br₂(l) → CaBr₂(s) b) P₄(s) + O₂(g) → P₄O₁₀(s) P₄(s) + 5O₂(g) → P₄O₁₀(s) c. C₄H₈(g) + O₂(g) → CO₂(g) + H₂O(g) C₄H₈(g) + 6O₂(g) → 4CO₂(g) + 4H₂O(g) d. HNO₃(aq) + Ca(OH)₂(aq) → H₂O(l) + Ca(NO₃)₂(aq) 2HNO₃(aq) + Ca(OH)₂(aq) → 2H₂O(l) + Ca(NO₃)₂(aq) ## Chapter 8 - 8.10 Balance each of the following chemical equations: a) HNO₃(aq) + Zn(s) → H₂(g) + Zn(NO₃)₂(aq) 2HNO₃(aq) + Zn(s) → H₂(g) + Zn(NO₃)₂(aq) b) H₂SO₄(aq) + Al(s) → H₂(g) + Al₂(SO₄)₃(aq) 3H₂SO₄(aq) + 2Al(s) → 3H₂(g) + Al₂(SO₄)₃(aq) c. K₂SO₄(aq) + BaCl₂(aq) → BaSO₄(s) + KCl(aq) K₂SO₄(aq) + BaCl₂(aq) → BaSO₄(s) + 2KCl(aq) d. CaCO₃(s) → CaO(s) + CO₂(g) CaCO₃(s) → CaO(s) + CO₂(g) e. AlCl₃(aq) + KOH(aq) → Al(OH)₃(s) + KCl(aq) AlCl₃(aq) + 3KOH(aq) → Al(OH)₃(s) + 3KCl(aq) ## Chapter 8 - 8.13 Write a balanced equation using the correct formulas, and include conditions (s, l, g or aq) for each of the following chemical reactions: a) Lithium metal reacts with liquid water to form hydrogen gas and aqueous lithium hydroxide. 2Li(s) + 2H₂O(l) → H₂(g) + 2LiOH(aq) b) Solid phosphorus reacts with chlorine gas to form solid phosphorus pentachloride. 2P(s) + 5Cl₂(g) → 2PCl₅(s) c) Solid iron(II) oxide reacts with carbon monoxide gas to form solid iron and carbon dioxide gas. FeO(s) + CO(g) → Fe(s) + CO₂(g) d) Liquid pentane (C₅H₁₀) burns in oxygen gas to form carbon dioxide gas and water vapor. 2C₅H₁₀(l) + 15O₂(g) → 10CO₂(g) + 10H₂O(g) e) Hydrogen sulfide gas and solid iron(III) chloride react to form solid iron(III) sulfide and hydrogen chloride gas. 3H₂S(g) + 2FeCl₃(s) → Fe₂S₃(s) + 6HCl(g) ## Chapter 8 - 8.14 Write a balanced equation using the correct formulas, and include conditions (s, l, g, or aq) for each of the following chemical reactions: a) Solid sodium carbonate decomposes to produce a solid sodium oxide and carbon dioxide gas. Na₂CO₃(s) → Na₂O(s) + CO₂(g) b) Nitrogen oxide gas reacts with carbon monoxide gas to produce nitrogen gas and carbon dioxide gas. 2NO(g) + 2CO(g) → N₂(g) + 2CO₂(g) c) Iron metal reacts with solid sulfur to produce solid iron(III) sulfide. 2Fe(s) + 3S(s) → Fe₂S₃(s) d) Solid calcium reacts with nitrogen gas to produce solid calcium nitride. 3Ca(s) + N₂(g) → Ca₃N₂(s) e) In the Apollo lunar module, hydrazine gas, N₂H₄, reacts with dinitrogen tetroxide gas to produce gaseous nitrogen and water vapor. N₂H₄ + N₂O₄ → 3N₂ + 2H₂O ## Chapter 8 - 8.21 Classify each of the following as a combination, decomposition, single replacement, double replacement, or combustion reaction: a. 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s) Combination b. Mg(s) + 2AgNO₃(aq) → 2Ag(s) + Mg(NO₃)₂(aq) Single replacement c. CuCO₃(s) → CuO(s) + CO₂(g) Decomposition d. Al₂(SO₃)₃(aq) + 6KOH(aq) → 2Al(OH)₃(s) + 3K₂SO₄(aq) Double replacement e. C₄H₈(g) + 6O₂(g) → 4CO₂(g) + 4H₂O(g) Combustion ## Chapter 8 - 8.22 Classify each of the following as a combination, decomposition, single replacement, double replacement, or combustion reaction: a) CuO(s) + 2HCl(aq) → CuCl₂(aq) + H₂O(l) Double replacement reaction b) 2Al(s) + 3Br₂(l) → 2AlBr₃(s) Combination reaction c) C₆H₁₂(l) + 9O₂(g) → 6CO₂(g) + 6H₂O(g) Combustion d) Fe₂O₃(s) + 3C(s) → 2Fe(s) + 3CO(g) Single replacement reaction e) C₆H₁₂O₆(aq) → 2C₂H₄O(aq) + 2CO₂(g) Decomposition reaction ## Chapter 8 - 8.45 Balance each of the following chemical equations, and identify the type of reaction (8.1, 8.2, 8.3): a) NH₃(g) + HCl(g) → NH₄Cl(s) NH₃(g) + HCl(g) → NH₄Cl(s) Combination b) C₄H₈(g) + O₂(g) → CO₂(g) + H₂O(g) C₄H₈(g) + 6O₂(g) → 4CO₂(g) + 4H₂O(g) Combustion c) Sb(s) + Cl₂(g) → SbCl₃(s) 2Sb(s) + 3Cl₂(g) → 2SbCl₃(s) Combination d) Ni₃(s) → N₂(g) + I₂(g) 2Ni₃(s) → 3N₂(g) + 9I₂(g) Decomposition e) KBr(aq) + Cl₂(aq) → KCl(aq) + Br₂(l) 2KBr(aq) + Cl₂(aq) → 2KCl(aq) + Br₂(l) Single replacement f) H₂SO₄(aq) + Fe(s) → H₂(g) + Fe₂(SO₄)₃(aq) 3H₂SO₄(aq) + 2Fe(s) → 3H₂(g) + Fe₂(SO₄)₃(aq) Single replacement g) Al₂(SO₄)₃(aq) + NaOH(aq) → Al(OH)₃(s) + Na₂SO₄(aq) Al₂(SO₄)₃(aq) + 6NaOH(aq) → 2Al(OH)₃(s) + 3Na₂SO₄(aq) Double replacement ## Chapter 8 - 8.48 Predict the products and write a balanced equation for each of the following (8.1, 8.2, 8.3). a) Decomposition: NaCl(s) → 2NaCl(s) → 2Na(s) + Cl₂(g) b) Combination: Ca(s) + Br₂(l) → Ca(s) + Br₂(l) → CaBr₂(s) c) Combustion: C₂H₄(g) + O₂(g) → C₂H₄(g) + 3O₂(g) → 2CO₂(g) + 2H₂O(g) d) Double replacement: NiCl₂(aq) + NaOH(aq) → NiCl₂(aq) + 2NaOH(aq) → Ni(OH)₂(s) + 2NaCl(aq)