Name _________________________ Period _____ Unit 2 Practice Test Use the following to answer questions 1 and 2. A student places a 2.4 g sample of magnesium ribbon into 500 mL of 2.0 M hydrochloric acid solution. The student records that bubbling occurs and that the ribbon disappears. 1. What is the balanced equation for this reaction? a. Mg + HCl MgCl + H b. Mg + 2HCl MgH2 + Cl2 c. Mg + 2HCl MgCl2 + H2 d. Mg + 2HCl Mg + Cl2 + H2 2. Identify which substance is being oxidized and which substance is being reduced in this laboratory investigation. a. Magnesium is being oxidized & the chloride ion is being reduced b. Magnesium is being reduced & the chloride ion is being oxidized c. Magnesium is being oxidized & the hydrogen ion is being reduced d. Magnesium is being reduced & the chloride ion is being oxidized 3. If 200 mL of 0.60 M MgCl2is added to 400 mL of distilled water, what is the concentration of Mg2+ (aq) and Cl- (aq) in the resulting solution? a. 0.20 M Mg2+ and 0.20 M Clb. 0.20 M Mg2+ and 0.40 M Clc. 0.40 M Mg2+ and 0.40 M Cld. 2.0 M Mg2+ and 2.5 M Cl4. Determine the amount of distilled water that should be added to 20.0 mL of 12.0 M HCl (aq) in order to prepare a 0.500 M HCl (aq) solution. a. 120 mL b. 140 mL c. 460 mL d. 480 mL 5. What is the molarity of a solution containing ClO2- (aq) if 15.0 mL of the solution is needed to react completely with 20.0 mL of 0.20 M KMnO4 solution? 2H2O (l) + 4 MnO4- (aq) + 3ClO2- (aq) 4 MnO2 (s) + 3 ClO4- (aq) + 4OH- (aq) a. b. c. d. 0.10 0.20 0.30 0.40 M M M M Use the following information for the next 2 questions. Solutions of lead (II) nitrate and potassium iodide react according to the following reaction: Pb(NO3)2 (aq) + 2KI (aq) PbI2 (s) + 2KNO3 (aq) Suppose that the lead nitrate is reacted with excess potassium iodide. 6. Which species act exclusively as spectator ions? a. K+ and NO3b. Pb2+ and Ic. K+ and Pb2+ d. I- and NO37. What would be the composition of the solution after the reaction occurs? a. Solid lead (II) iodide and equal numbers of potassium ions and nitrate ions b. Solid lead (II) iodide and more potassium ions than nitrate ions c. Solid lead (II) iodide and potassium, nitrate and iodide ions in unequal amounts d. Solid lead (II) iodide and equal numbers of potassium, nitrate and iodide ions. 8. A sample of 25.0 mL of 0.120 M Ca(OH)2 (aq) is titrated with 0.150 M HCl (aq). What volume of HCl (aq) is needed to completely neutralize the Ca(OH)2 (aq)? a. 20.0 mL b. 40.0 mL c. 60.0 mL d. 80.0 mL 9. In which of the following species is the oxidation state for nitrogen the greatest? a. NO b. NO2 c. N2O d. N2O5 10. A 1.0 M solution of table salt (NaCl) is considered to be 1.0 M Na+ and 1.0 M Cl-. This means table salt is a: a. Strong electrolyte b. Weak electrolyte c. Nonelectrolyte d. Strong acid 11. What volume of 0.2000 M sulfuric acid is required to neutralize 800.0 mL of 0.1000 M potassium hydroxide? a. 200.0 mL b. 400.0 mL c. 800.0 mL d. 1600.0 mL 12. Consider 100.0 mL of a 1.00 M solution of NaCl in a beaker. After several days, you test the solution and find that it has a concentration of 1.33 M. How much water must have evaporated? a. 20.0 mL b. 25.0 mL c. 75.0 mL d. 80.0 mL 13. What volume of 10.0 M NaOH must be used to prepare 500 mL of a 2.50 M solution? a. 125 mL b. 200 mL c. 250 mL d. 12.5 mL 14. Hydrogen reacts with oxygen to form water. If 16 grams of hydrogen is mixed with 16 grams of oxygen, how much water can form? a. 0.50 grams b. 8.0 grams c. 18 grams d. 72 grams 15. Consider the neutralization reaction Be(OH)2 (s) + 2HCl (aq) BeCl2 (aq) + 2H2O (l). What volume of 5.00 M HCl is required to react completely with 4.30 g of Be(OH)2? (Molar mass of Be(OH)2 = 43.0 g/mol) a. 10.0 mL b. 30.0 mL c. 40.0 mL d. 50.0 mL 16. Solutions of CaCl2 and Na2CO3 are mixed and a precipitate is formed. What is the net ionic equation for the reaction? a. CO32- (aq) + Ca2+(aq) CaCO3 (s) b. 2Cl- (aq) + 2Na+ (aq) 2NaCl (s) c. CO32- (aq) + Ca2+(aq) + 2Cl- (aq) + 2Na+ (aq) CaCO3 (s) + 2NaCl (aq) d. CO32- (aq) + Ca2+(aq) Ca(CO3)2 (s) 17. Which of the following pairs of ions would not form a solid in aqueous solution? a. Ba2+ and SO4b. Pb2+ and Brc. Na+ and SO4d. Pb2+ and S218. a. b. c. d. The oxidation number of N in Ca(NO3)2 is: +2 +3 +4 +5 Free Response: 19. Two solutions are prepared, one of Cu(NO3)2 and one of KOH. a. Draw molecular representations of the two solutions, assuming that one beaker contains four formula units of Cu(NO3)2 and the other beaker contains six formula units of KOH. Cu(NO3)2 KOH b. Draw a molecular representation of the solution that results when the contents of the beakers are mixed. Include the correct number of formula units or ions, and the correct amounts and kinds of ions remaining. Resulting Solution c. Write the balanced net ionic equation for the reaction. 20. Nonprescription antacids may contain MgO, Mg(OH)2, or Al(OH)3. a. Write a balanced neutralization reaction for the neutralization of hydrochloric acid by each of these substances. b. Which of these substances will neutralize the greatest amount of 0.1 M HCl per gram?