Correct answer is asterisked . CHEM1010 - Fundamentals of Chemistry - Semester 1 2012 SECTION A: MULTIPLE CHOICE QUESTIONS The electron configuration diagrams below labeled A and B represent two possible configurations for element 6, carbon. Questions 1 and 2 refer to these diagrams: B A 1s 2s 2py 2px 2pz 1 Is 2s 2py 2px 2pz 1) Which one of the following statements about the configurations A and B is TRUE? * - (A) Configuration A represents the lowest energy electron configuration of carbon. (B) Configuration B represents the lowest energy electron configuration of carbon. (C) Configurations A and B are of equal energy and the atom would exist in equilibrium between the two. (D) Neither of these configurations represents the lowest energy electron configuration of carbon. (E) Carbon has two valence electrons. 2) Which one of the following statements about the configurations A and B is FALSE? (A) Of the two electrons in the 1s orbital, one must have a spin quantum number of 1/2 and one must have a spin quantum number equal to -1/2. (B) Hund's Rule allows us to determine which of these is the lowest energy configuration. (C) The 2p orbitals are higher in energy than the 2s orbital because of the shielding effects of the electrons in the 2s orbital and the fact that the 2s electrons penetrate to the nucleus more effectively than the electrons in the 2p orbitals. (D) The electrons in the 2s orbital are valence electrons even though they are in an orbital with a slightly lower energy than the highest energy electrons. Configuration B violates the Pauli Exclusion Principle. * -> (E) Question 3 next page Page 1 of 10
CHEM1010 - Fundamentals of Chemistry - Semester 1 2012 3) Which one of the following set of quantum numbers could correctly describe an electron in one of the 2p orbitals above? * 1 1 (A) n= 2 1=2 m1=2 mg = +1/2 (B) n=2 1=0 (C) n=2 1=1 m1= 0 Ms = +1/2 m?=1 m$ =- 1/2 (D) n=2 1=1 (E) n=2 1= 1 m1=1 Ms = 1 m?=2 mg = - 1/2 Questions 4 and 5 refer to the Lewis structure of CIF3 4) Taking into account any lone pairs on the central atom (CI), what geometry is adopted by CIF3? * > (D) Trigonal bipyramidal (A) Linear (B) Trigonal planar (C) Tetrahedral (E) Octahedral 5) What is the approximate angle between the lone pairs of electrons on the central atom (C1) in CIF3? (A) 180° * (B) 120° (C) 90° (D) 45° (E) There is only one lone pair in CIF3 Questions 6, 7 and 8 refer to capsaicin, the molecule responsible for the hot spiciness of chillies. The abbreviated structure of capsaicin is given below. Most of the hydrogen atoms have been omitted from the diagram of the structure. Note: This diagram is not a Lewis structure. H3CO. V ZI b a .CH 3 HO Capsaicin CH 3 Question 6 next page Page 2 of