CH 223 SPRING FINAL EXAM June 6, 2011 DO NOT OPEN THIS EXAM UNTIL TOLD TO DO SO

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1 CH 223 SPRING FINAL EXAM June 6, 2011 This exam has 33 questions worth 5 pts each, plus one question worth 3 pts. The total possible score is 168 pts. DO NOT OPEN THIS EXAM UNTIL TOLD TO DO SO Before the exam begins you can do the following on the Scantron answer sheet. Use a #2 pencil. 1. Fill in your name (LAST NAME, FIRST NAME) in the large box on the left. Don't forget to bubble in the circles below your name. 2. Fill in your student ID number in the box labeled "IDENTIFICATION NUMBER". Do not use dashes or blank spaces. Fill in the circles as well. 3. In the box labeled "CLASS SECTION NUMBER", enter the appropriate number 8 am class = section 001 (Nafshun) 9 am class = section 002 (Nafshun) 12pm class = section 003 (Watson) 3pm class = section 004 (Ferguson) 4. There is no "TEST FORM NUMBER" ONLY ONE APPROVED NOTECARD IS ALLOWED ALL PHONES AND OTHER ELECTRONIC DEVICES OTHER THAN CALCULATORS MUST BE OFF You may keep this exam packet and your notecard when the exam period is complete. Show your ID and hand in the Scantron answer sheet to a TA at the end of the exam.

2 PTE K a [CH 3 COOH (aq)] = 1.80 x 10-5 (acetic acid) K a [CH 2 ClCOOH (aq)] = 1.40 x 10-3 (chloroacetic acid) K a [HCOOH (aq)] = 1.80 x 10-4 (formic acid) K sp [PbF 2 ] = 3.6 x 10-8 K sp [MgF 2 ] = 3.7 x 10-8 K sp [Cd(OH) 2 ] = 7.2 x K sp [PbI 2 ] = 1.4 x 10-8 K a [HF (aq)] = 1.80 x 10-5 (acetic acid) K a [C 6 H 5 COOH (aq)] = 6.30 x 10-5 (benzoic acid) K b [NH 3 (aq)] = 1.80 x 10-5 (ammonia) K b [CH 3 CH 2 NH 2 ] = 5.37 x 10-4 (ethylamine) K a [niacin (aq)] = 1.5 x 10-5

Spectrochemical series: CN - > NO 2 - > en > NH 3 > NCS - > division > H 2 O > OH - > F - > Cl - F = 96,485 C/mole e - R = 8.314 J/mol K N A = 6.02 x 10 23 S = k ln W h = 6.

3 Spectrochemical series: CN - > NO 2 - > en > NH 3 > NCS - > division > H 2 O > OH - > F - > Cl - F = 96,485 C/mole e - R = J/mol K N A = 6.02 x S = k ln W h = x J s/photon Gº rxn = -RT ln K G rxn = Gº rxn + RT ln Q c = 3.00 x 10 8 m/s E cell = E cell - ln Q Gº = -nf E cell G = H - T S E = 1 Amp = HNO 3 (g) N 2 H 4 (l) H 2 O(l) ΔG f (kj/mol)

4 Reduction Half-Reaction E º, volt Acidic Solution F 2 (g) + 2 e - 2F - (aq) O 3 (g) + 2 H + (aq) + 2 e - O 2 (g) + H 2 O(l) S 2 O 2-8 (aq) + 2 e - 2 SO 2-4 (aq) H 2 O 2 (aq) + 2H + (aq) + 2 e - 2 H 2 O(l) MnO - 4 (aq) + 8H + (aq) + 5 e - Mn 2+ (aq) + 4 H 2 O(l) PbO 2 (s)+ 4H + (aq) + 2 e - Pb 2+ (aq) + 2 H 2 O(l) Cl 2 (g) + 2 e - 2 Cl - (aq) Cr 2 O 2-7 (aq) + 14 H + (aq) + 6 e - 2 Cr 3+ (aq) + 7 H 2 O(l) MnO 2 (s) + 4H + (aq) + 2 e - Mn 2+ (aq) + 2 H 2 O(l) O 2 (g) + 4H + (aq) + 4 e - 2 H 2 O(l) IO - 3 (aq) +12H + (aq) + 10 e - I 2 (s) + 6 H 2 O(l) Br 2 (l) + 2 e - 2 Br - (aq) NO - 3 (aq) + 4H + (aq) + 3 e - NO(g) + 2 H 2 O(l) Ag + (aq) + e - Ag(s) Fe 3+ (aq) + e - Fe 2+ (aq) O 2 (g) + 2H + (aq) + 2 e - H 2 O 2 (aq) I 2 (s) + 2 e - 2 I - (aq) I - 3 (aq) + 2 e - 3 I - (aq) Cu 2+ (aq) + 2 e - Cu(s) SO 2-4 (aq) + 4H + (aq) + 2 e - 2 H 2 O(l) + SO 2 (g) Sn 4+ (aq) + 2 e - Sn 2+ (aq) S(s) + 2H + (aq) + 2 e - H 2 S(g) H + (aq) + 2 e - H 2 (g) 0 Pb 2+ (aq) + 2 e - Pb(s) Sn 2+ (aq) + 2 e - Sn(s) Co 2+ (aq) + 2 e - Co(s) Cr 3+ (aq) + e - Cr 2+ (aq) Fe 2+ (aq) + 2 e - Fe(s) Zn 2+ (aq) + 2 e - Zn(s) Al 3+ (aq) + 3 e - Al(s) Mg 2+ (aq) + 2 e - Mg(s) Na + (aq) + e - Na (s) Ca 2+ (aq) + 2 e - Ca(s) K + (aq) + e - K(s) Li + (aq) + e - Li(s) Basic Solution O 3 (g) + H 2 O(l) + 2 e - O 2 (g) + 2 OH - (aq) OCl - (g) + H 2 O(l) + 2 e - Cl - (aq) + 2 OH - (aq) O 2 (g) + 2 H 2 O(l) + 4 e - 4 OH - (aq) H 2 O(l) + 2 e - H 2 (g) + 2 OH - (aq)

1. Niacin, one of the B vitamins, has the following molecular structure: O O-H N What is the [H 3 O + ] of a 0.020M aqueous solution? 5.5 x 10-4 M 3.0 x 10-7 M 0.020 M 4.0 x 10-4 M 2.8 x 10-4 M 2.

5 1. Niacin, one of the B vitamins, has the following molecular structure: O O-H N What is the [H 3 O + ] of a 0.020M aqueous solution? 5.5 x 10-4 M 3.0 x 10-7 M M 4.0 x 10-4 M 2.8 x 10-4 M 2. Which statement about the ph curve is TRUE. The titration used M NaOH and ml of an acid. A) The acid could be M HCl. B) The acid could be M HCN. C) The acid could be M H 3 PO 4. D) The acid could be M HCN. E) The acid could be M HCl.

6 3. What would the ph of an aqueous solution made from calcium acetate, Ca(CH 3 COO) 2 be? Neutral, ph=7 Acidic, ph<7 Basic, ph>7 Need more information to determine 4. The ph of a buffer system which is M CH 3 COOH (aq) and 1.40 M CH 3 COONa (aq) is: A student titrates grams of KHP (potassium hydrogen phthalate; MW=204.2 g/mol) to the equivalence point with ml of NaOH (aq). The concentration of the NaOH solution is: 15.4 M 13.6 M M M M

7 6. Consider the reaction of ammonia (NH 3 ), and water. The conjugate acid is: H 2 O NH 3 HCOO - H + + NH 4 7. The concentration of NaOH in water is gradually increased without changing the volume significantly. Which of the following describes what happens to the concentrations of H 3 O + and OH -, the ph and the poh? Concentration of H 3 O + Concentration of OH - ph poh increases increases increases decreases increases decreases increases decreases decreases increases decreases increases decreases decreases decreases increases decreases increases increases decreases 8. The molar solubility of Ag 2 SO 4 in water is M. What is the value of K sp?

8 9. Which isomer is shown below? H 2 N H 2 N 2- Pt Cl Cl Cis Trans Fac Mer Not an isomer 10. Which of the following Ti 3+ complexes exhibits the shortest wavelength absorption in the visible spectrum? [Ti(H 2 O) 6 ] 3+ [Ti(en) 3 ] 3+ [TiCl 6 ] 3- [Ti(H 2 O) 6 ] 3+ [Ti(en) 3 ] 3+ [TiCl 6 ] 3- Cannot Determine All have the same wavelength absorption 11. How many unpaired electrons would you expect for the complex ion: [Mn(NH 3 ) 6 ] 3+? The Haber process for the production of ammonia is exothermic and involves the following equilibrium reaction: N 2 (g) + 3H 2 (g) 2NH 3 (g). Assuming ΔHᵒ and ΔSᵒ do not change with temperature predict the direction in which ΔGᵒ for this reaction changes with increasing temperatures. A. Moves towards the reactants B. Moves towards the products C. The reaction is not temperature dependent and ΔGᵒ will not change D. Values for ΔHᵒ and ΔSᵒ are needed to calculate ΔGᵒ

9 13. Which of the following statements involving the 3 rd law of thermodynamics is FALSE? It allows us to assign entropy values for substances at different temperatures Perfect crystalline solids have zero entropy at 0K. The standard molar entropy of elements is zero The standard molar entropy of a gas is greater than a solid The standard molar entropy increases with the number of atoms in a formula. 14. Which of the following processes have a ΔS > 0? CH 3 OH(l) CH 3 OH(s) N 2 (g) + 3 H 2 (g) 2 NH 3 (g) CH 4 (g) + H 2 O (g) CO(g) + 3 H 2 (g) Na 2 CO 3 (s) + H 2 O(g) + CO 2 (g) 2 NaHCO 3 (s) All of the above processes have a ΔS > Calculate the ΔG rxn for the following reaction (thermodynamic data at front of exam). 4 HNO 3 (g) + 5 N 2 H 4 (l) 7 N 2 (g) + 12 H 2 O(l) J kj kj kj kj 16. When the following redox reaction is balanced correctly in acidic solution you will have H + and H 2 O. Mn 2+ (aq) + BiO 3 - (s) Bi 3+ (aq) + MnO 4 - (aq) 14 H + and 7 H 2 O 7 H + and 7 H 2 O 7 H + and 14 H 2 O 8 H + and 4 H 2 O 2 H + and 1 H 2 O

10 17. An electrochemical cell consists of one beaker containing 1.0 M AgNO 3 (aq) into which dips a piece of metallic silver and a second beaker containing 1.0 M Zn(NO 3 ) 2 (aq) into which dips a piece of metallic zinc. The beakers are connected by a salt bridge containing 1.0 M KNO 3 (aq). Which of the following statements will be TRUE when a wire is connected between the two pieces of metal? Electrons will flow from the silver to the zinc. The cell voltage will be V. There will be no cell voltage as the overall reaction is non-spontaneous. The silver will plate out on the zinc. The value of n used to find ΔG for this cell has the value A student provides a current of 8.0 amps through a solution of Co 2+ (aq) for 6.00 hours. The voltage is such that cobalt metal is deposited at the cathode. The mass of cobalt deposited is: 12.2 g 24.4 g 62.1 g 52.8 g 105 g 19. What is the name of the following structure? 2,4-diethylheptane 4,6-diethylheptane 2,4-dimethylheptane 4,6-dimethylheptane 5-ethyl-3-methyloctane

11 20. The molecular formula of Vitamin C (shown below) is: is C 7 H 8 O 6 is C 7 H 6 O 6 is C 7 H 4 O 6 is C 6 H 4 O 6 is C 6 H 8 O Which of the following is NOT an isomer of 2-methyl-3-ethylheptane? 5-methylnonane 2-methyl-4-ethylheptane 2,2,3,4,4-pentamethylpentane 2,4-diethyl-3-isopropylpentane decane

12 22. Complete the following reaction: 23. Complete the following condensation reaction:

13 24. In a single step, CH 2 O is oxidized to: CH 3 CH 3 CH 3 OH benzene an amide HCOOH 25. Complete the following addition reaction:

14 26. Which of the following functional groups is not present in Amoxicillin? amine aldehyde carboxylic acid alcohol Amoxicillin 27. A β-sheet is an example of primary structure secondary structure tertiary structure quaternary structure an aldohexose

15 28. The following is the structure of galactose. Which of the following statements is false: Galactose is a monosaccharide Galactose is an aldohexose Galactose has 5 chiral carbons Galactose is a carbohydrate Galactose is an aldehyde 29. Consider the fat molecule below. Which of the following is false? H H H H C C O C O O O O H O It is a triglyceride it is saturated it contains cis bonds it contains trans bonds could undergo hydrogenation

16 30. What monomer was reacted to create the following addition polymer?

17 31. The organic product of benzene and in the presence of AlCl 3 is:

18 32. Carnosine is highly concentrated in muscle and brain tissues. Carnosine is the dipeptide: Pro-Glu Ala-Gly Gly-Ala Gln-His His-Gln 33. DNA forms a double helix structure. Which of the following statements explains how this helix forms? The sugar groups form hydrogen bonds between two complementary strands to form a helix. The phosphate groups from two strands wrap around one another to form a helix. The base groups form hydrogen bonds between two complementary strands to form a helix. The sugar and phosphate form a phosphoester linkage that bonds two complementary strands to form a helix. The sugar groups form hydrogen bonds between two complementary strands to form a helix.

19 34. Well, well, well... CH 223 is over. Time to... head home, work a summer job, and try to forget about chiral carbons. cry; possibly for hours. two words: Twitter and Skittles. refurnish my room to resemble Gilbert 124. I plan on reliving general chemistry every day of my life; for it has been a breathtaking experience I cannot live without. recover from the full-body discomfort brought on by the study of entropy. [Any response will receive full credit; even no response.] Questions 1 through 33 have five points attached (165 total). Any response to Question 34 will receive full credit (3 Points total); even no response. The point total for this exam is 168 points. See the grade sheet for grade computation details. Final exam keys, scores, and course grades will be posted on the CH 223 website as they become available. Have a great life. Go out there and do some really cool stuff :)

Chemistry 223 Spring 2012 Oregon State University Exam 2 May 24, 2012 Drs. Nafshun, Watson, Richardson

Chemistry 223 Spring 2012 Oregon State University Exam 2 May 24, 2012 Drs. Nafshun, Watson, Richardson Instructions: You should have with you several number two pencils, an eraser, your 3" x 5" note card,