CHEM 1311H/1411 Final Exam Fall 2000 13 December 2000 Use Pencil—Do Not Use Pen Circle Your Answer—Only the “Letter” Name ___________________________ Student Number______-_____-______ 1. In the reaction: A2+(aq) + B(s)  B2+(aq) + A(s) A. A2+ is oxidized B. B2+ is reduced C. B is the reducing agent D. A is reduced E. All of the above 2. Only 2.5 x 105- g of tetrahydrocannabinol (THC), the active ingredient in marijuana, is required to produce intoxication.. How many molecules of THC (C21H30O2; 314.5 g/mol) are required for intoxication? A. 25 x 105 molecules B. 7.95 x 108- molecules C. 8.0 x 108- molecules D. 6.022 x 1023 molecules E. 4.8 x 1016 molecules 3. 4. The volume of a gas is doubled while the temperature is held constant. The pressure of the gas… A. is reduced by one-half. B. is increased by one-forth. C. doubles. D. varies depending upon the nature of the gas. E. remains unchanged. 5. 6. Arrange the following ions in order of decreasing size: A. Mg2+ > Ca2+ > Ca B. Mg2+ > Ca > Ca2+ C. Ca > Ca2+ > Mg2+ D. Ca > Mg2+ > Ca2+ E. Ca2+ > Mg2+ > Ca 7. What is the correct formula for ammonium cyanide? A. Al(CN)3 B. NH4NO3 C. NH4CN D. NaNO3 E. NH3N3 8. What is the oxidation number of oxygen in the major reaction product resulting from the interaction of potassium metal with an excess of oxygen? A. 0 B. +1/2 C. +1 D. -1 E. -1/2 9. Vinegar contains acetic acid (60.05 g/mol) and reacts with sodium hydroxide (40.0 g/mol) according to the reaction given below: CH3COOH(aq) + NaOH(aq)  Na(CH3COO)(aq) + H2O(aq) You find that a 25.00 mL sample of vinegar requires 28.33 mL of a 0.953 M solution of NaOH for titration to the equivalence point. Calculate the molar concentration of the acetic acid in the vinegar. A. 1.068 M B. 2.14 M C. 0.127 M D. 0.190 M E. 1.62 M 10. 11. 12. How many grams of Na2CO3 (106.0 g/mol) are required to prepare 2.0 L of a 1.5 M Na2CO3 solution? A. 80.0 B. 106.6 C. 160.0 D. 240.0 E. 320.0 13. 14. 15. (1) H2O (2) HF (3) BCl3 Which of the following is true? A. 3 is polar B. 1 and 3 are polar C. 1 is polar D. 2 and 3 are polar E. 1, 2, and 3 are polar 16. The empirical formula of maleic acid is CHO. Its molar mass is 116.1 g/mol. Its molecular formula is: A. CHO B. C2H2O2 C. C4H4O4 D. C5H5O5 E. C6H6O6 17. Butylated hydroxytoluene (BHT) (below) is widely used as a food preservative. According to valence bond theory, what is the total number of bonds present in BHT? A. 23 B. 15 C. 30 D. 52 E. 43 18. 19. Consider the two similar compounds below: OHCH3CCCH3H3CCH3CH3CH3CH3HHPtNH3NH3ClClPtCl ClNH3NH3(I) (II) Compound (I), cisplatin, is used in cancer therapy. The molecular structure of both compounds is square planar. Which would be expected to be soluble in pentane, C5H12? A. (I) B. (II) C. Neither D. Both E. Depends upon pH level 20. Commercial concentrated nitric acid is 69% HNO3 (63.01 g/mol) by weight and has a density of 1.42 g/mL. What is the molarity of this solution: A. 2.0 M B. 4.0 M C. 8.0 M D. 16 M E. 32 M 21. Determine the oxidation number of phosphorus in Mg2P2O4. A. 1 B. 2 C. 3 D. 4 E. 5 22. Two (2.000) moles of Ni atoms have the same mass as 1.223 moles of atoms of which other element. A. Sn B. Pd C. Ga D. Mo E. Pt 23. Consider the following reaction Fe2O3(s) + 3CO(g)  2Fe(s) + 3CO2(g) If you begin with 150 g of Fe2O3 (159.7 g/mol) as the limiting reagent, calculate the theoretical yield of iron (55.6 g/mol). A. 105 g Fe B. 300 g Fe C. 75 g Fe D. 50 g Fe E. 120 g Fe 24. According to Valence Bond Theory, predict the hybridization of the central atom in XeF4? A. sp B. sp2 C. sp3 D. sp3d E. sp3d2 25. Molecule X effuses twice as fast as Molecule Y. Thus, the molecular mass of X is the molecular mass of Y. A. twice B. one-fourth C. four times D. one-half E. the same as 26. Which is the largest bond angle? A. angle O-S-O in SO3 B. angle Cl-C-Cl in HCCl3 C. angle F-Be-F in BeF2 D. angle H-O-H in H2O E. angle H-S-H in H2S 27. Which is planar? A. PCl3 B. ClO3- C. CO32- D. NH3 E. PH3 28. 29. How many unpaired electrons are present in Zn2+? A. 0 B. 1 C. 2 D. 3 E. 4 30. Which of the following has delocalized electrons? 31. 32. In the balanced equation describing the complete combustion of dodecane, C12H26, what is the oxygen coefficient? A. 1 B. 2 C. 37 D. 24 E. 26 33. What is the molecular structure of IF5? A. sea-saw B. pyramidal C. octahedral D. square pyramidal E. trigonal bipyramidal 34. The following reaction gave a 60% yield of NaOH. How many milligrams of NaOH were produced in this reaction? 2 Na + 2 H2O  2 NaOH + H2 23.0 mg 36.0 mg A. 12.0 mg B. 20.0 mg C. 24.0 mg D. 45.0 mg E. 80.0 mg HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHABCDE35. A solution of NaOH (40.0 g/mol) is standardized against potassium hydrogen phthalate (KHP; 204.2 g/mol). HHHHCCOOHOO-K++ NaOHH2O++K-HHHHCCOOOO-Na+ From the following data calculate the molarity of the NaOH solution. mass of KHP: 0.8407 g buret reading before titration: 0.23 mL buret reading after titration: 38.78 mL A. 0.1068 M B. 0.214 M C. 0.320 M D. 0.427 M E. 0.534 M ******************************************************** CHEM 1311H/1411 Final Exam Grade Calculation: There are 35 problems with a value of 3 points each. Your grade is simply based upon the number of correct answers multiplied by three. Thus, it is possible to score “105” (out of “100”). CHEM 1311H/1411 Final Grade Calculation: Your Final Grade in this course may be derived as described in the course syllabus: Average of Best Three Hour Exams: 65% Score on Final Exam: 35% 100% Post Exam Protocol: There is no curving or extra credit associated with this course. You will receive your grade from The University in the prescribed fashion. Phone or email inquiries concerning CHEM 1311H/1411 final grades cannot be honored. Please record your answers on a sheet of paper such that you may