Chem 1C - Spring 2010 - FINAL EXAM ON YOUR SCANTRON: BUBBLE IN YOUR 7 DIDGIT PERM (Leaving the last three digits blank) BUBBLE IN THE VERSION: WRITE YOUR NAME AT THE END, HAND IN ONLY THE SCANTRON. INFORMATION ΔT = K b m solute ΔT = K f m solute Π = MRT P soln = X solvent Po solvent P TOTAL = P A + P B XA = (na + nb)/na P = k H X ln(p vap )= - (ΔH vap /R)(1/T)+C Q heating = S sp.heat Mass ΔT Q phase change = ΔH (# Mols) λυ = c E = hυ n λ = 2 d sin θ h = 6.626 x 10-34 J s c = 3.0 x 10 8 m/s R = 0.08206 L atm mol -1 K -1 1.0 atm = 760 Torr 1
1. Which of the following sets of quantum numbers describes a 3d electron: n l m l m s 1 0 0 +½ 2 0 0 -½ 4 2 +2 +½ 3 2-2 -½ 2 1 0 -½ 2. Which of the following atoms is the most electronegative: K F Mg C Cs 3. Which of the following statements is correct: A double bond is composed of two σ bonds A triple bond is composed of three π bonds Multiple bonds are stronger than single bonds Single bonds are stronger than multiple bonds Single bonds are shorter than multiple bonds 4. Given this graph, what is the boiling point of carbon tetrachloride? 0 o C 20 o C 77 o C 95 o C 100 o C 2
5. Which of the following molecules has the shortest carbon-oxygen bond length: CH 3 OH CO CO 2 2- CO 3 They are all equal 6-7. Predict the molecular structure and the angle closest to the bond angles for SF 6 6: shape 7: bond angle linear 90 o square planar 107 o tetrahedral 45 o C trigonal planar 120 o octahedral 180 o 8. In which of the following processes will energy by released (in the form of heat)? sublimation melting vaporization condensation none of these For questions 9-14 consider phenylalanine, pictured here: O a O H NH 2 9. What type of molecule is this? amino acid ester coordination complex salt diatomic 3
10. In this diagram all carbon atoms and most hydrogen atoms are omitted. What is the molecular formula of this molecule? H 3 NO 2 C 9 H 3 NO 2 C 6 H 8 NO 2 C 9 H 11 NO 2 C 9 H 11 NO 11 11. What is the hybridization of the carbon atom labeled α? sp3 it is not hybridized sp d2sp3 sp2 12. What is the hybridization of the carbon atoms that form the six membered ring? sp3 it is not hybridized sp pd sp2 13. How many electrons are involved in π bonding? 0 2 4 6 8 14. What is the approximate C-O-H angle between the 2 bonds of the oxygen atom indicated in the figure? 180 o 90 o 120 o 0 o 109 o 4
Question 15-17 refer to the following complex: [Co(NH 3 ) 6 ]Cl 3 15. What is the geometry? linear trigonal planar tehtrahedral trigonal bipyramidal octahedral 16. What is the name? hexaaminocobalt(vi)chloride teraminocobalt(iii)chloride hexaaminocobalt(iii)chloride tetrachlorocobalt(iii)amine hexaaminocobalt(ii)chloride 17. How many d electrons does it have? 3 4 5 6 7 18. Which of the following is paramagnetic: C 2 N 2 F 2 O 2 H 2 19. CO 2 is a greenhouse gas because it absorbs heat radiation from the earth. It has the following Lewis structure ::O=C=O:: Which is a true statement: CO 2 has a measurable permanent dipole CO 2 has no measurable permanent dipole but it can have a dynamic dipole (from a bending vibration) CO 2 never has any dipole (and so it never absorbs IR radiation) all of the above none of the above 5
20. A 10 g sample of a large biomolecule was dissolved in 100 g of carbon tetrachloride (boiling-point constant 5 C kg/mol). The boiling point of this solution was determined to increase by 1 C. What is the molar mass of the biomolecule? 10 g/mol 100 g/mol 200 g/mol 500 g/mol 1000 g/mol 21. Which has the most polar bond? H-Cl O-O H-I H-H All the same 22. Suppose in each atomic orbital there could be not 2 but 3 electrons. Which would be the first rare gas instead of He? H He Li Be Ne 23. A solution contains 46 g of ethanol (C 2 H 5 OH), 32 g of methanol (CH 3 OH) and 54 g of water. What is the mole fraction of the water? 0.32 0.46 0.6 1 2 24. Which of the following has the highest boiling point? H 3 C-O-CH 3 (dimethyl ether) C 4 H 10 (butane) CO 2 CH 4 (methane) HO-CH 3 (methanol) 6
25. How many geometrical and linkage isomers of Co(NH 3 ) 4 (NO 2 ) 2 appear in the figure below? 1 2 3 4 5 26. A salt A x B y, when dissolved in water dissociates completely as follows: A x B y xa +yb. Dissolving 1 mol of a A x B y, in 1 liter of water (K f =1.86 o C kg/mol) lowers the freezing point to - 5.58 o C. Which of the following can represent its empirical formula? AB A 2 B A 3 B A 2 B 3 A 2 B 2 27. When a vapor condenses which of the following is a true statement? The gibbs free energy, ΔG increases The entropy, ΔS, decreases The entropy, ΔS increases The enthalpy, ΔH increases None of the above 7
28. How many resonant structures are there for CO 3 2 0 1 2 3 4 29. The unit cell in a certain lattice of atoms X and Y consists of a cube formed by an X at each corner of the cube, a Y at the center of the cube and a Y at the center of each face. The empirical formula of the compound is: XY 4. X 5 Y 6. X 5 Y 3. XY. X 2 Y 2. 30-31. What are the bond angles for the following molecules: 30. SeO 2 31. SeO 3 90 o 90 o 109.5 o 109.5 o 120 o 120 o 180 o 180 o 360 o 360 o 32. Which of the following is paramagnetic? [CoF 6 ] 3 (strong field) [Co(NH 3 ) 6 ] 3+ (strong field) [Zn(H 2 O) 6 ] 2+ [Co(F) 6 ] 3 (weak field) none of these 33. The color of a transition metal complex results from bending vibrations. stretching vibrations. transition of an electron between d orbitals. transition of an electron between an s and a p orbital. nuclear magnetic resonance. 8
34. Consider the following amino acids: amino acid name R-group glycene Gly H alanine Ala CH 3 cysteine Cys CH 2 SH Which of these amino acids are optically active (have stereoisomers)?. Gly and Ala Ala and Cys Gly and Cys All three of these amino acids none of these amino acids 35 How much energy does it take to boil 18 grams of water, starting at 25 o C (Specific heat capacity S water = 4.46 J/g o C and ΔH vap = 40.7 kj/mol)? 44.9 J 46730 J 10 6 J 18 x 10 6 J 46.73 J 36. Which are arranged in order of increasing intermolecular forces? CsBr < CO < CH 3 OH < I 2 < Cl 2 CO < Cl 2 < I 2 < CH 3 OH < CsBr I 2 < Cl 2 < CO < CH 3 OH < CsBr Cl 2 < I 2 < CO < CsBr < CH 3 OH Cl 2 < I 2 < CO < CH 3 OH < CsBr 37. Which of the following have bond order 0.5: + H 2, H 2 and H 2 H 2, H + + 2 and He 2 H 2 and He 2 B 2 and Li 2 O 2 9
38. A 0.1 molar solution of NaCl at 244 o K has an osmotic pressure of: 0.5 atm 1 atm 760 atm 4 atm 7 atm 39. How many isomers of C 5 H 12 are there? 1 2 3 4 5 40. For propene in which one hydrogen is replaced by a chlorine atom (C 3 H 5 Cl), how many possible isomers are there? 1 2 3 4 5 41. Smaller intermolecular forces in a liquid lead to Higher vapor pressure smaller viscosity lower boiling point (b) and (c) all of the above 42. The configuration (σ2s) 2 (σ2s*) 2 (σ2p) 2 (π2p) 4 (π2p*) 4 is the molecular orbital description for the valence shell ground state of Li 2+ 1- N 2 O 2 2 O 2 C 2 10
43. In a diffraction experiment with 1 nm X-rays the first order (n=1) diffraction angle is 30 o. What is the distance between the atoms that produce the diffraction? 0.1 nm 0.5 nm 1 nm 5 nm 10 nm 44. Which of the following could be the boiling point of water on Mount Everest? 0 0 C 90 0 C 100 0 C 105 0 C 200 0 C 45. In ethene, C 2 H 4 the valence orbitals of the carbon atoms are hybridized as follows: not hybridized sp sp2 sp3 dsp 46. The sequence of amino acids in a polypeptide chain determines which type of protein structure? primary structure secondary structure tertiary structure quaterniary structure globular structure 47. Which of the compounds below is an example of an ionic solid? diamond SiO 2 graphite CaCO 3 C 25 H 52 11
48. At a given temperature, the vapor pressure of heptane is 100 torr and the vapor pressure of octane is 40 torr. Assuming ideal behavior, what is the vapor pressure of a solution that contains three times as many moles of heptane as octane? 140 torr 100 torr 85 torr 75 torr 45 torr 49. Consider the following codons: CUA codes for Leu, AGC codes for Ser, and AAG codes for Phe. What tripeptide is coded for by the following DNA sequence: TTCGATTCG? Phe-Leu-Ser Leu-Phe-Ser Leu-Ser-Phe Ser-Phe-Leu Phe-Ser-Leu 50. A perfume bottle lists the following ingredients: methylphenylpropanal, propanol, methyl-butanone, water. The perfume contains molecules of the following types: alcohol aldehyde ketone all of the above none of the above BONUS: Oxygen is transported between the heart and lungs of mammals which type ofmolecule? hemoglobin myoglobin chlorophyll cytochrome prophyrin Don t forget: perm number name - version Have a great summer! 12
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