Chem 10 – Test 4B – page 1 of 4Test 4 Name ____________________________Chemistry 10 – Dr. Kline27 May 2004 Row ________ Seat ________ Lab 8:00 10:30This test consists of a combination of multiple choice and other questions. There should be a total of25 questions on 6 pages plus a page with equations and other information; please check to makesure that they are all here. You may use the equation/information sheet and any periodic tableprovided (last page). Do not use your own tables, scratch paper or other information. Do not shareyour calculator. Please turn off all cell phones, pagers and other communication devices; if theymake noise, they will be confiscated. Shared calculators will be confiscated. It is OK to tear off theperiodic table page.Multiple Choice QuestionsEach of the following 20 questions is worth three points, for a total of 60 points. There is only onecorrect answer for each question unless it is stated otherwise for a given question. Answer eachquestion by circling the letter(s) corresponding to the correct choice(s); in other words, if there ismore than one correct answer, circle all of the correct ones. It is not necessary to show work forthese questions; however, you may write on the exam.1. A transition from the solid phase directly to the gas phase is known as…a. sublimationb. boilingc. depositiond. evaporatione. melting2. What kinds of intermolecular forces are present in the molecule below? If more than one kind ispresent, circle all of them that are present.CCHOHHHa. hydrogen bondingb. dispersion forcesc. dipole-dipole interactionsd. none of the above3. Circle the compound that is expected to have the higher boiling point.C C C OHHHHHHHHO C C OHHHHHH4. Circle the compound that is expected to have the lowest vapor pressure.HCHF FHCHBr BrHCHCl ClHCHI I5. Circle the compound that is expected to have the higher boiling point:H C C OHHHHH H C C SHHHHHChem 10 – Test 4B – page 2 of 46. Circle all of the compounds in the group below that are capable of intermolecular dipole-dipoleinteractions. More than one is possible.HCHF FHCHI IH C O CHHH H C NHH HHHH7. Which of the following has the highest melting point?a. KIb. CI4c. Krd. I28. What happens when additional solid solute is added to a unsaturated solution?a. It dissolves until its solubility limit is reached.b. It doesn’t dissolve.c. It doesn’t dissolve and additional solute comes out of solution. 9. In which of the following solvents would sucrose, a polar substance, be expected to be soluble?More than one answer may be correct.a. hexane, C6H14b. waterc. ethanol (structure on the left in problem#5)10. The solubility of carbon dioxide in water is about 1.5 g per 100 g of water at 30 °C. Which ofthe following would cause the solubility of carbon dioxide in water to increase?a. a decrease in temperatureb. an increase in the pressure of nitrogen gas over the solutionc. an increase in the pressure of carbon dioxide gas over the solutiond. none would11. Which of the following has the lower freezing point?a. pure waterb. 0.10 M NaCl(aq)c. neither, because they both have the same freezing pointd. it is impossible to tell12. Two aqueous solutions of glucose, C6H12O6, are placed in a U-tube. A semi-permeablemembrane at the bottom of the tube separates the two solutions. What happens? More thanone of the listed things might happen.a. glucose molecules move from right to leftthrough the membraneb. water molecules moves from left to rightthrough the membranec. the liquid level on the right side decreasesd. nothing happens13. How many grams of NaOH are present in 100. mL of 0.10 M NaOH(aq)?a. 0.010 gb. 0.10 gc. 40 gd. 4.0 ge. 0.40 gChem 10 – Test 4B – page 3 of 414. What volume of 2.00 M KCl is needed to prepare 500. mL of 0.100 M KCl?a. 25.0 mLb. 40.0 mLc. 50.0 mLd. 100. mLe. 250. mL15. What is the concentration of hydroxide ion, [OH–], in 0.20 M Ba(OH)2 ?a. < 0.10 Mb. 0.20 Mc. 0.40 Md. > 0.40 M16. What is the pH of 0.10 M HC2H3O2 at 25 °C?a. pH = 7b. pH > 7c. pH < 717. Which of the following corresponds to the most basic solution?a. pH = 4.00b. [OH–] = 1.0 x 10–3 Mc. [H+] = 1.0 x 10–8 M18. Which of the following solutions would have [H+] > 0.10 M? More than one answer may becorrect.a. 0.10 M HNO2b. 0.10 M HNO3c. 0.10 M H2SO419. Suppose that 100. mL of 0.20 M KOH is combined with 125 mL of 0.10 M HCl. Is the resultingsolution acidic, basic, or neutral?a. acidicb. basicc. neutral20. Which of the following aqueous mixtures is/are buffer solutions? More than one answer may becorrect.a. HI and KIb. HF and KFc. HClO and NaCld. none of themChem 10 – Test 4B – page 4 of 4Problems and QuestionsEach of the following is worth the indicated number of points, for a total of 40 points. Please showwork, with units, to receive credit unless instructed otherwise. Also, be sure to provide all of theinformation requested for each question.21. 9 points An aqueous solution is prepared by dissolving 17.5 g KNO3 in 125 mL of water. Notethat the density of water is 1.00 g/mL. Assume that the density of the solution is 1.12 g/mL.a. What is the percent by mass of the KNO3 in the solution?b. What is the molarity of the KNO3 in the solution?22. 6 points Write balanced reaction equations, with state labels, to show why each of the followingis true.a. Hydrocyanic acid, HCN, is a weak acid.b. Chlorite ion, ClO2–, is a weak base.23. 8 points Calculate the [OH–], [H+], and pH of 0.0082 M KOH at 25 °C. Clearly show allequations used and remember that you must show work or a set-up for any mathematicalprocess that you cannot do in your head.24. 8 points How many grams of aluminum are needed to react with 85.0 mL of 4.0 M HBr by thereaction 2Al(s) + 6HBr(aq) ‡ 2AlBr3(aq) + 3H2(g)?25. 9 points A student analyzes an aqueous solution of acetic acid, HC2H3O2, as follows. First, hepipets 20.00 mL of the solution into an Erlenmeyer flask using a volumetric pipet and then adds25 mL of distilled water and 3 drops of phenolphthalein to the solution. He then cleans and fillsa buret with 0.1105 M NaOH. The initial volume reading of the buret is 0.63 mL. He then addsNaOH from the buret to the acetic acid solution until a pale pink endpoint is obtained. At thispoint the volume reading on the buret is 38.63 mL. What is the molarity of the acetic acid tothe correct number of significant digits?Chem 10 Information for Test 4 – Spring 2004Electronegativity