Question 1 How many carbon atoms are in 1 mol of sucrose (C 12 H 22 O 11 )? A) 7.23 x 10 24 B) 6.02 x 10 23 C) 5.02 x 10 22 D) 12 E) 342 3-1
Question 2 Calculate the mass % of hydrogen in ammonium bicarbonate. A) 5.166 % B) 8.392 % C) 6.387 % D) 22.82 % E) Cannot be determined with the information given. 3-2
Question 3 Iron reacts slowly with oxygen and water to form a compound commonly called rust (Fe 2 O 3 4H 2 O). In 65.2 kg of rust, calculate the amount (moles) of Fe 2 O 3. A) 0.281 mol B) 3.56 mol C) 281 mol D) 408 mol E) 1125 mol 3-3
Question 4 An oxide of nitrogen contains 30.45 % N by mass. If the molar mass is 90 ± 5 g/mol, what is the molecular formula of the oxide? A) NO 2 B) N 2 O 4 C) N 3 O 7 D) N 2 O E) N 4 O 2 3-4
Question 5 A balanced chemical equation A) provides the identity of the reactants and products. B) provides the molar ratios of the products and reactants. C) indicates the physical state of the reactants and products. D) shows that the total mass of the reactants is equal to the total mass of the products. E) all of the above 3-5
Question 6 Convert the following statement into a balanced equation. When solutions of calcium chloride and sodium phosphate are mixed, solid calcium phosphate forms and sodium chloride remains in solution. A) CaCl (aq) + NaPO 4(aq) CaPO 4(s) + NaCl (aq) B) CaCl 2(s) + Na 2 PO 4(s) CaPO 4(c) + 2NaCl (s) C) 3CaCl (aq) + Na 3 (PO 4 ) 2(aq) Ca 3 (PO 4 ) 2(s) + 3NaCl (aq) D) 3CaCl 2(aq) + 2Na 3 PO 4(aq) Ca 3 (PO 4 ) 2(s) + 6NaCl (aq) E) CaCl 3 (aq) + Na 3 (PO 4 )2(s) CaPO 4(s) + 3NaCl (aq) 3-6
Question 7 Calculate the mass of hydrogen gas produced when 33.61 g of diborane (B 2 H 6 ) reacts with excess water. A) 2.45 g B) 14.72 g C) 150.2 g D) 131.7 g B 2 H 6(g) + 6H 2 O (l) 2H 3 BO 3(s) + 6H 2(g) E) Must know the amount of water to calculate this value. 3-7
Question 8 Two sets of successive reactions, D - E and E - F, have respective yields of 48% and 73%. What is the overall percent yield for conversion of D to F? A) 25% B) 48% C) 73% D) 35% E) 1.25% 3-8
Question 9 Calculate the volume in litres of 0.385 mol/l manganese(ii) sulfate that contains 57.0 g of solute. A) 1.48 L B) 0.981 L C) 0.688 L D) 0.145 L E) 1.02 L 3-9
Question 10 Which of the following is a true statement. A) A mole of one substance has the same number of atoms as a mole of any other substance. B) The theoretical yield for a reaction is based on the results obtained in the laboratory. C) A limiting-reactant problem is presented when the quantity of available material is given in moles for one of the reactants. D) To prepare 1.00 L of 3.00 M NaCl, weigh 175.5 g of NaCl and add 1.00 L of distilled water to it. E) The concentration of a solution is an intensive property, but the amount of solute in a solution is an extensive property. 3-10
Question 11 What amount (mol) of oxygen atoms is there in 6 moles of Al 2 (SO 4 ) 3? A) 4 B) 12 C) 18 D) 72 3-11
Question 12 Which one of the following statements is true? A) A mole of Ca 3 (PO 4 ) 2 contains 8 moles of phosphorus atoms. B) A mole of Fe(NO 3 ) 3 contains (9)(6.022 x 10 23 ) atoms of oxygen. C) A molecule of AlCl 3 contains (3)(6.022 x 10 23 ) atoms of chlorine. D) A molecule of Na 2 SO 4 contains 4 sulfate ions. 3-12
Question 13 Butyric acid has an empirical formula of C 2 H 4 O and a molecular mass of approximately 88 u. What is the molecular formula? A) C 2 H 4 O B) C 2 H 4 O 2 C) 2 C 2 H 4 O D) C 4 H 8 O 2 3-13
Question 14 How would you classify the following chemical reaction? C 2 H 5 OH + 3 O 2 2 CO 2 + 3 H 2 O A) combination B) decomposition C) combustion D) precipitation 3-14
Question 15 For the following reaction: Ca + 2 H 2 O Ca(OH) 2 + H 2 What amount (mol) of H 2 is formed from the reaction of 6 moles of H 2 O? A) 1 B) 2 C) 3 D) 6 3-15
Question 16 A bicycle maker has 18 handlebars, 15 frames, and 20 tires. Assuming all other parts are available, what is the limiting "reactant" and how many bicycles can be made? A) frames, 20 B) frames, 10 C) tires, 20 D) tires, 10 3-16
Question 17 Calculate the molar mass of Al 2 (SO 4 ) 3 A) 123.04 g/mol B) 150.03 g/mol C) 278.02 g/mol D) 341.99 g/mol 3-17
Question 18 Household sugar, sucrose, has the molecular formula C 12 H 22 O 11. What is the % carbon in sucrose, by mass? A) 26.7 % B) 33.3 % C) 41.4 % D) 42.1 % E) 52.8 % 3-18
Question 19 When the following reaction is balanced, the coefficient for HF will be: A) 6 B) 3 C) 2 D) 1 B 2 O 3(s) + HF (l) BF 3(g) + H 2 O (l) 3-19
Question 20 When the following reaction is balanced with whole numbers, the coefficient of oxygen will be: A) 1 B) 6 C) 9 D) 15 C 6 H 6(l) + O 2(g) H 2 O (g) + CO 2(g) 3-20
Question 21 Calculate the concentration (mol/l) of a solution prepared by diluting 1.85 L of 6.5 mol/l KOH to 11.0 L. A) 0.28 M B) 0.91 M C) 1.1 M D) 3.1 M E) 3.9 M 3-21
Question 22 What is the concentration (mol/kg) of a solution prepared by dissolving 86.9 g of ethoxyethane (diethyl ether, C 4 H 10 O), in 425 g of benzene, C 6 H 6? A) 0.362 mol/kg B) 0.498 mol/kg C) 2.01 mol/kg D) 2.76 mol/kg E) none of the above 3-22
Question 23 Consider the following balanced redox reaction: 2CrO 2- (aq) + 2H 2 O(l) + 6ClO - (aq) 2CrO 4 2- (aq) + 3Cl 2 (g) + 4OH - (aq) Which species is being reduced? A) CrO 2 - B) ClO - C) CrO 4 2- D) Cl 2 E) OH - 3-23
Question 24 The equation given is unbalanced. It is an acidic reaction. Identify which species is the reducing agent. Sb(s) + NO 3 - (aq) Sb 4 O 6 (s) + NO(g) A) NO - 3 B) Sb C) H 2 O D) NO E) Sb 4 O 6 3-24
Question 25 What is the oxidation number of phosphorus in Ca 3 (PO 4 ) 2? A) +2 B) +4 C) -3 D) +5 E) +10 3-25
Question 26 For the following, partially balanced, half-reaction, how many water molecules must be added to completely balance the reaction and to which side should they be added? C 2 O 4 2-2 CO 3 2- A) 1 H 2 O, reactants B) 1 H 2 O, products C) 2 H 2 O, reactants D) 2 H 2 O, products 3-26
Question 27 In the following balanced redox reaction, which species is being oxidized? 8 H + (aq) + MnO 4 - (aq) + 5 Fe 2+ (aq) Mn 2+ (aq) + 5 Fe 3+ (aq) + 4 H 2 O (l) A) Mn 7+ B) Fe 2+ C) H + D) O 2-3-27
Question 28 When the following equation is balanced with smallest whole number coefficients, the coefficient for NO 2 will be. I 2 (s) + HNO 3 (aq) HIO 3 (aq) + NO 2 (g) + H 2 O (l) A) 1 B) 2 C) 4 D) 10 3-28
Question 29 What is the molality of a solution consisting of 2.77 ml of tetrachloromethane (d = 1.59 g/ml) in 79.5 ml of dichloromethane (d = 1.33 g/ml)? A) 0.0348 mol/kg B) 2.71 mol/kg C) 0.752 mol/kg D) 0.0399 mol/kg E) 0.271 mol/kg 3-29
Question 30 What is the most common unit of concentration? A) molality B) mole fraction C) parts by mass D) mol/l (also called molarity) E) mole percent 3-30
Question 31 For a given solution, which of the following concentration values will change as temperature changes? A) mass percent B) molality C) mole fraction D) mol/l E) none of the above 3-31
Question 32 Consider the following balanced redox reaction: 2CrO 2- (aq) + 2H 2 O(l) + 6ClO - (aq) 2CrO 4 2- (aq) + 3Cl 2 (g) + 4OH - (aq) Which species is being reduced? A) CrO 2 - B) ClO - C) CrO 4 2- D) Cl 2 E) OH - 3-32
Question 33 The equation given is unbalanced. It is an acidic reaction. Identify which species is the reducing agent. Sb(s) + NO 3 - (aq) Sb 4 O 6 (s) + NO(g) A) NO - 3 B) Sb C) H 2 O D) NO E) Sb 4 O 6 3-33
Question 34 What is the oxidation number of phosphorus in Ca 3 (PO 4 ) 2? A) +2 B) +4 C) -3 D) +5 E) +10 3-34
Question 35 Consider the following balanced redox reaction: 3 CuO (s) + 2 NH 3 (g) N 2 (g) + 3 H 2 O (l) + 3 Cu (s) Which of the following statements is true? A) CuO(s) is the oxidizing agent and Cu is reduced. B) CuO(s) is the oxidizing agent and Cu is oxidized. C) CuO(s) is the reducing agent and Cu is oxidized. D) CuO(s) is the reducing agent and Cu is reduced. E) CuO(s) is the oxidizing agent and N 2 (g) is the reducing agent. 3-35
Answer Key Chapter 3 3-36 1. A 2. C 3. C 4. B 5. E 6. D 7. B 8. D 9. B 10. E 11. D 21. C 31.D 12. B 22. D 32 B 13. D 23. B 33 B 14. C 24. B 34 D 15. C 25. D 35 A 16. D 26. C 17. D 27. B 18. D 28. D 19. A 29 E 20. D 30 D