Chemistry Raymond Chang 10th edition Chapter 4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Question 11 When calcium carbonate is placed in water, which of the following best describes what is present in the mixture? A) calcium carbonate molecules only B) calcium ions and carbonate ions only C) mostly calcium ions and carbonate ions and little undissociated calcium carbonate D) a few calcium ions and carbonate ions and a lot of undissociated calcium carbonate E) hydrated calcium and carbonate ions only 0% 1 0% 0% 2 3 0% 0% 4 5 Question 14 The equation Fe3+(aq) + 3OH-(aq) → Fe(OH)3 represents A) a balanced molecular equation. B) a balanced ionic equation. C) a balanced net ionic equation. D) a dissociation reaction. E) an example of a redox reaction. 0% 1 0% 0% 2 3 0% 0% 4 5 Question 16 Which of the following species should be considered a weak Bronsted acid? A) HI B) OHC) HNO3 D) HClO4 E) None of the above 0% 1 0% 0% 2 3 0% 0% 4 5 Question 18 In which of the following species is the oxidation number of manganese highest? 38% A) MnO2 B) Mn2(SO4)3 C) K2MnO4 D) KMnO4 E) MnO3 38% 13% 6% 1 6% 2 3 4 5 Question 19 Which of the following equations does not represent a redox reaction? A) Cu + 2AgNO3 → 2Ag + Cu(NO3)2 B) 2CrO42- + 2H+ → Cr2O72- + H2O 31% C) 2SO2 + O2 → 2SO3 D) 2H2 + O2 → 2H2O 19% 19% E) All are redox 25% 6% 1 2 3 4 5 Question 20 A sample of oxalic acid (a diprotic acid of the formula H2C2O4) is dissolved in enough water to make 1.00 L of solution. A 100.0 mL sample of this solution is titrated with a solution of sodium hydroxide of concentration 0.750 M and requires 20.0 mL of sodium hydroxide to reach the end point. Calculate the mass of the original oxalic acid sample. A) 6.75 g B) 0.675 g C) 1.35 g D) 13.5 g E) None of the above 38% 25% 19% 13% 6% 1 2 3 4 5 23.48mL of a NaOH solution are needed to neutralize 0.5468g of KHP (MW 204.2 g/mol). What is the concentration of the base solution? 1. 2. 3. 4. 0.1141M 0.002678M 1.14M Can’t tell 88% 6% 1 2 6% 3 0% 4 Answer Key – Chapter 4 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. D D B A A C D D B B 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. D A C C A B E D B A