Chemistry Training Test for Exam 2

Practice Exam #2 Answers I. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Multiple choice C A A D A D E B E E 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. D D B A B A D D C A 21. 22. 23. 24. 25. 26. 27. 28. B B C C B D B C II. PROBLEMS 29. The molarity of a solution of 5.0 g of KCl in 100. mL of solution is __ 0.67M______. 30. What volume of 0.10 M NaOH can be prepared from 250. mL of 0.30 M NaOH? 31. what is the pH of a solution that has a [OH-] = 3.5 x 10-8 M? 32. What is the concentration of in a solution with pH = 2.50? 33. If we add water to 100 µl of a 45.6ppm solution until the final volume is 150 µl, what will the concentration of the new solution be? 34. Cardiac arrest victims are sometimes treated by injection of a calcium chloride solution directly into the heart muscle. If 2.0 mL of a 5.0% (m/V) CaCl2 solution is administered to a patient, what mass of CaCl2 was provided? 35. The label on a jar of jam says it contains 13 g of sucrose per tablespoon (15 mL). What is the molarity of sucrose in the jam? [Molar mass: sucrose, 342.3 g/mol] 36. What happens when a hypotonic solution is separated from a hypertonic solution by an osmotic membrane? The solvent moves from the hypotonic solution to the hypertonic solution 37. What term is used to describe a solution of lower osmolarity compared to one with a higher osmolarity? Hypotonic solution 38. Antacids are used to relieve heartburn. Despite the many commercial brands, almost all antacids contain one of the following bases: sodium bicarbonate NaHCO3 and Magnesium Hydroxide Mg(OH)2. Write the products of the neutralization reaction between each antacid and gastric juice (HCl) PRACTICE EXAM #2 The exam will cover material from Chapters 10, 11, 12, 5, 6, 8 and 9, homework, quizzes, and labs. The questions in this practice exam are of similar difficulty to those in the actual exam; however, the questions will not be the same. I. Multiple choice 1. Which of the following substances is NOT a solution? A. humid air B. beer E. All of the above are solutions. C. oxygen D. steel 2. What mass (in grams) of fructose (C6H12O6) is contained in 125 mL of a 0.500 M fructose solution? A. 11.3 B. 11300 C. 721 D. 0.0625 E. 180 3. A. B. C. D. E. In order for a solute to dissolve in solution: the solute-solvent forces must be greater than the solute-solute forces. the solute-solute forces must be greater than the solute-solvent forces. the solute-solvent forces must equal the solute-solute forces. the polarity of the solute and solvent must be opposite. none of the above 4. When an ionic compound dissolves in water: A. the solvent-solute attractive forces overcome the solute-solute attractions. B. the positive end of water dipoles attract the negative ions. C. the negative end of water dipoles attract the positive ions. D. each of the above (A, B, and C) occurs. E. none of the above (A, B, or C) occurs. 5. According to the Arrhenius concept, if HNO3 were dissolved in water, it would act as: ___. A. An acid C. A source of H- ions B. A base D. A proton acceptor 6. You need to prepare 2.00 L of 0.100 M Na2CO3 solution. The best procedure is to weigh out: A. 10.6 g Na2CO3 and add 2.00 L of water to it. B. 21.2 g Na2CO3 and add 2.00 L of water to it. C. 0.6 g Na2CO3 and add water until the final solution has a volume of 2.00 L. D. 21.2 g Na2CO3 and add water until the final solution has a volume of 2.00 L. 7. How do molecules with polar functional groups behave differently than molecules with nonpolar functional groups? A. Molecules with polar functional groups are more reactive. B. Molecules with polar functional groups have higher boiling points. C. Molecules with polar functional groups can be soluble in water. D. Molecules with polar functional groups have higher melting points. E. All of the above 8. A 90.0 g sample of NaOH is dissolved in water and the solution is diluted to give a final volume of 3.00 liters. The molarity of the final solution is ________. A. 0.500 M B. 0.750 M C. 1.00 M D. 2.25 M E. NA 9. According to the Brønsted-Lowry definition, ________. A. a base produces H+ ions in aqueous solutions B. an acid acts as the solvent C. an acid is a proton acceptor D. a base is a proton donor E. a base is a proton acceptor 10. The [H3O+] of a solution with pH = 2.0 is ________. A) -10 M C) 1X102M D) 1X10-12M B) 10M E) 1X10-2M 11. What type of membrane allows solvent molecules to pass through but do not allow solute molecules to pass through? C. Transparent E. Filtering A. Transport B. Colloidal D. Semipermeable 12. A. B. C. D. E. What is always a characteristic of a solution that contains a buffer The solution is neutral and has a pH of 7. The solution contains a small amount of solute dissolved in a large volume of solvent. The solution has been diluted by the addition of solvent. The solution resists large changes in pH when small amounts of acids or bases are added. The solution maintains a constant pH value; no amount of added acid or base can change the pH. 13. Butyric acid is a weak acid. Which reaction equation properly represents the dissociation of butyric acid in water? A. CH3CH2CH2COOH(aq) + H2O(l) → CH3CH2CH2COO– (aq) + H3O+(aq) B. CH3CH2CH2COOH(aq) + H2O(l) CH3CH2CH2COO–(aq) + H3O+(aq) C. CH3CH2CH2COOH(aq) + H2O(l) → CH3CH2CH2COOH2+(aq) + OH–(aq) D. CH3CH2CH2COOH(aq) + H2O(l) CH2CH2CH2COOH(aq) + H3O+(aq) E. Both A and B are correct. 14. A sample of black coffee was measured to have [H 3O+] = 7.94 × 10−6. What is true about this solution? A. The solution is acidic, B. The solution contains less hydronium ions than pure water itself. C. The solution does not contain any OH− ions. D. The solution has [OH−] = 7.94 × 10−6. E. The pH of the solution is 7.94. 15. Which compound below forms an electrolyte solution when dissolved in water? E) none of the above A) Cl2 C) CH3CH2OH D) C12H22O11 (sucrose) B) KOH 16. A solution at 25°C has a hydrogen ion concentration of 2.6 × 10-5 M. Which of the following is TRUE? E) none of the A) [H3O+] > [OH-] C) [H3O+] = [OH-] D) [H3O+] = above B) [H3O+] < [OH-] 17. Which of the following equations (not balanced) represents an oxidation-reduction process? C) C2H4 + O2 → CO2 + H2O A) AgNO3 + NaCl → AgCl + NaNO3 B) C + O2 → CO2 D) more than one response is correct 18. The Haber Process is a method for the production of ammonia, an important chemical intermediate. The reaction for this process is N2 + 3H2 → 2NH3 According to the mole interpretation, how many grams of NH3 could be produced by the complete reaction of 2.80 grams of N2 and excess H2? A) 34.0 B) 17.0 C) 3.10 D) 3.40 19. Sulfur reacts with oxygen to produce sulfur dioxide, but only if the high activation energy is supplied. Which condition will lower the activation energy the most? A) stirring the mixture C) using a catalyst B) heating the mixture D) activation energy cannot be lowered 20. Which statement is a correct application of Le Châtelier's principle? A. Addition of a substance to the left side of an equilibrium shifts it to the right. B. Any stress to the right side of a chemical equilibrium results in a shift to the left to relieve the stress. C. Heat added or taken away from a chemical equilibrium in which one side is exothermic will not shift the reaction. D. Any stress to the right side of a chemical equilibrium results in a shift to the left side to relieve the stress, and heat added or taken away from a chemical equilibrium in which one side is exothermic will not shift the reaction. 21. The amine given shown is ______ A. primary B. Secondary C. Tertiary D. Quaternary 22. What is the correct IUPAC name for the following compound? A. N-methylaniline B. 2-methylaniline C. 1-methylaniline D. 1-methyl-2-aniline 23. What is the correct IUPAC name for the compound given below? A. 1-methyl-3-benzoic acid B. 3-methyl-1-benzoic acid C. 3-methylbenzoic acid D. 3-methylbenzoate 24. The IUPAC name of the ester formed from methanol and benzoic acid is called A. methyl benzoic acid C. methyl benzoate B. methanol benzoate D. benzyl methanoate 25. What is the IUPAC name for compound shown below? A. Methylbutanone B. 2-methylcyclobutanone 26. A. B. C. D. C. 1-methylcyclobutanal D. 1-methylcyclobutanone Which of the following properly ranks the relative aqueous solubility of each functional group? alkene < aldehyde < alcohol < ketone aldehyde < ketone < alkene < alcohol alkene < ketone < alcohol < aldehyde alkene < ketone < aldehyde < alcohol 27. Which of the following compounds would you expect to be foul smelling A. CH3CH2CH2OH B. CH3CH2CH2SH C. CH3CH2CH2CH3 D. CH3CH2CH2CHO 28. What is the correct IUPAC name for compound shown? A. 1,2-cyclopentadiol B. 1,5-cyclopentanediol C. 1,2-cyclopentanediol D. 1,5-cyclopentadiol II. PROBLEMS 29. The molarity of a solution of 5.0 g of KCl in 100. mL of solution is ________. 30. What volume of 0.10 M NaOH can be prepared from 250. mL of 0.30 M NaOH? 31. what is the pH of a solution that has a [OH-] = 3.5 x 10-8 M? 32. What is the concentration of in a solution with pH = 2.50? 33. If we add water to 100 µl of a 45.6ppm solution until the final volume is 150 µl, what will the concentration of the new solution be? 34. Cardiac arrest victims are sometimes treated by injection of a calcium chloride solution directly into the heart muscle. If 2.0 mL of a 5.0% (m/V) CaCl2 solution is administered to a patient, what mass of CaCl2 was provided? 35. The label on a jar of jam says it contains 13 g of sucrose per tablespoon (15 mL). What is the molarity of sucrose in the jam? [Molar mass: sucrose, 342.3 g/mol] 36. What happens when a hypotonic solution is separated from a hypertonic solution by an osmotic membrane? 37. What term is used to describe a solution of lower osmolarity compared to one with a higher osmolarity? 38. Antacids are used to relieve heartburn. Despite the many commercial brands, almost all antacids contain one of the following bases: sodium bicarbonate NaHCO3 and Magnesium Hydroxide Mg(OH)2. Write the products of the neutralization reaction between each antacid and gastric juice (HCl)