Exam #5 May 2, Closed Book Exam - No books or notes allowed. All work must be shown for full credit. You may use a calculator.

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1 Chem 110 Name Exam #5 May 2, 2017 Closed Book Exam - No books or notes allowed. All work must be shown for full credit. You may use a calculator. Question Credit TOTAL Multiple Choice 3 ⅓ points each. Before answering any of the questions, complete and balance the reaction. 1. How many moles of oxygen gas react with mol of pentane, C 5 H 12? spark C 5 H 12 (g) + O 2 (g) CO 2 (g) + H 2 O(g) mol mol mol 2. Considering the limiting reactant concept, how many moles of copper(i) sulfide are produced from the reaction of 1.00 mol of copper and 1.00 mol of sulfur? 2 Cu(s) + S(s) Cu 2 S(s) 1.00 mol 1.50 mol 2.00 mol 3. What is the mass of barium hydroxide ( g/mol) dissolved in L of M Ba(OH) 2 solution? 8.57 g 17.1 g 85.7 g 171 g 857 g

2 4. Which of the following increases the rate of dissolving for a solid solute in a solvent? grinding the solute heating the solution stirring the solution all of the above 5. What is the mass of solute dissolved in 50.0 g of a 12.5% saline solution? 4.00 g 6.25 g 7.14 g 43.8 g 625 g 6. What is the molarity of a saline solution that contains g NaCl (58.44 g/mol) dissolved in ml of solution? M M 1.54 M 1.90 M 5.27 M 7. What is the mass of barium hydroxide ( g/mol) dissolved in L of M Ba(OH) 2 solution? 8.57 g 17.1 g 85.7 g 171 g 857 g 8. What is the molarity of an acetic acid solution prepared by diluting ml of M HC 2 H 3 O 2 to a total volume of 1.00 L? M M M 1.00 M 2.50 M

3 9. What volume of 18 M sulfuric acid must be diluted with distilled water to prepare ml of 0.50 M H 2 SO 4? ml 0.14 ml 1.4 ml 14 ml 140 ml 10. What volume of M sulfuric acid reacts completely with g of sodium hydrogen carbonate, NaHCO 3 (84.01 g/mol)? 2 NaHCO 3 (s) + H 2 SO 4 (aq) Na 2 SO 4 (aq) + 2 H 2 O(l) + 2 CO 2 (g) 5.95 ml 29.8 ml 59.5 ml 119 ml 1.00 L 11. Which of the following is a strong acid? HCl(aq) H 2 SO 4 (aq) HNO 3 (aq) all of the above 12. If 20.0 ml of M KOH is titrated with M HNO 3, what volume of nitric acid is required to neutralize the base? HNO 3 (aq) + KOH(aq) KNO 3 (aq) + H 2 O(l) 10.0 ml 20.0 ml 25.0 ml 40.0 ml 50.0 ml 13. If 25.0 ml of M Ca(OH) 2 is titrated with M HNO 3, what volume of nitric acid is required to neutralize the base? 2 HNO 3 (aq) + Ca(OH) 2 (aq) 2 Ca(NO 3 ) 2 (aq) + 2 H 2 O(l) 12.5 ml 20.0 ml 25.0 ml 40.0 ml 50.0 ml

4 14. If a 50.0 ml sample of ammonium hydroxide is titrated with 25.0 ml of M sulfuric acid to a methyl red endpoint, what is the molarity of the base? 2 NH 4 OH(aq) + H 2 SO 4 (aq) (NH 4 ) 2 SO 4 (aq) + 2 H 2 O(l) M M M M M 15. What is the molarity of a sodium hydroxide solution if ml of NaOH is required to neutralize g of oxalic acid, H 2 C 2 O 4, (90.04 g/mol)? H 2 C 2 O 4 (aq) + 2 NaOH(aq) Na 2 C 2 O 4 (aq) + 2 H 2 O(l) M M M M M 16. Given an aqueous solution in which the [ H + ] = , what is the molar hydroxide ion concentration? [ OH ] = M [ OH ] = M [ OH ] = M [ OH ] = M [ OH ] = M 17. What is the ph of an aqueous solution if the [ H + ] = 0.1 M? What is the ph of an aqueous solution if the [ H + ] = M?

5 19. What is the [ H + ] in an acid rain sample that registers 3.22 using a ph meter? 0.51 M M M M M 20. What is the [ OH ] in a seawater sample if the ph is 8.65? 0.22 M 5.35 M M M M 21. What is the definition of a strong acid? An acid with a high ph An acid that produces H + An acid that completely dissociates in water An acid that dissolves metals 22. How many moles of calcium metal react to yield of hydrogen gas? mol 1.00 mol 2.00 mol Ca(s) + H 2 O(l) Ca(OH) 2 (aq) + H 2 (g) 23. How many moles of oxygen gas react to yield 1.00 mol NO 2? UV NO(g) + O 2 (g) NO 2 (g) mol 1.00 mol 2.00 mol

6 24. What is the molarity of a nitric acid solution prepared by diluting ml of 6.00 M HNO 3 to a total volume of 2.50 L? M M M 2.50 M 6.00 M 25. If 25.0 ml of urine has a mass of g and contains g of solute, what is the mass/mass percent concentration of the specimen? 1.93% 7.50% 7.72% 37.6% 97.2% 26. What is the mass of solute dissolved in 10.0 g of a 5.00% sugar solution? g g g 9.50 g 10.0 g 27. What is the mass of nickel(ii) nitrate ( g/mol) dissolved in 25.0 ml of M Ni(NO 3 ) 2 solution? g g 4.00 g 45.7 g 457 g 28. Given an aqueous solution in which the [ H + ] = , what is the molar hydroxide ion concentration? [ OH ] = M [ OH ] = M [ OH ] = M [ OH ] = M [ OH ] = M

7 29. Considering the limiting reactant, what mass of cobalt(iii) sulfide ( g/mol) is produced from g of cobalt and g of sulfur? 2 Co(s) + 3 S(s) Co 2 S 3 (s) g 1.36 g 2.34 g 2.72 g 5.45 g 30. What volume of antifreeze must be added to 6 liters of water to produce a mixture that is 40% anti-freeze? 2 L 4 L 6 L 8 L 60 L Answer Key 1. D 2. A 3. A 4. D 5. B 6. A 7. A 8. A 9. D 10. B 11. D 12. D 13. C 14. C 15. D 16. C 17. B 18. D 19. E 20. C 21. C 22. B 23. B 24. C 25. B 26. B 27. B 28. E 29. A 30. B