University:
Purdue University
Course:
CHM 11200 | General Chemistry
Academic year:

2005
Views:

109

Pages:

3
Author:

faillithepo

Chemistry 123 Exam 3 November 21, 2005 KEY 1. For dinitrogen monoxide, the arrangement of atoms is N-N-O. In the Lewis structure with a double bond between NN and NO, the formal charges on N, N, and O, respectively, are (a) –1, +1, 0 (b) 0, –1, +1 (c) 0, +1, –1 (d) 0, 0, 0 (e) –2, +1, +1 2. All of the following have a linear shape except (a) CS2 (b) CH2 (c) I3 2+ – (d) O3 (e) OCS (order as written) 2– 3. What is the shape of SO4 ? (a) trigonal planar (b) trigonal pyramidal (c) seesaw (d) tetrahedral (e) T-shaped 14 10 4. All of the following can have the ground-state electron configuration [Xe]4f 5d except (remember – e- come out of 6s first!) 2+ (a) Hg (b) Tl + (c) Bi 5+ + (d) Au 4+ (e) Pb 2– 2– 2– 2– 5. Arrange the following elements in order of increasing ionic radius: Te , O , Se , S (a) Te 2– calcium > magnesium (c) magnesium > barium > calcium (b) magnesium > calcium > barium (d) magnesium < calcium < barium Arrange the following four electromagnetic spectral regions in order of increasing energy. visible ultraviolet infrared radio (a) visible < ultraviolet < radio < infrared (b) radio < ultraviolet < visible < infrared (c) radio < infrared < visible < ultraviolet (d) infrared < ultraviolet < visible < radio (e) infrared < visible < ultraviolet < radio 8. Determine the energy of a photon that has a wavelength of 645 nm. -48 (a) 1.43 × 10 -28 (b) 3.08 × 10 -25 (c) 1.99 × 10 -19 J (d) 3.08 × 10 J 14 J (e) 4.65 × 10 J J 9. Which of the following completely defines the set of azimuthal quantum numbers that can exist for n = 3? (a) l = 0 (b) l = 0, 1 (c) l = 0, 1, 2 (d) l = 0, 1, 2, 3 10. Which set of quantum numbers is not allowed? (a) n = 0, l = 0, ml = 0, ms = +1/2 (b) n = 1, l = 0, ml = 0, ms = +1/2 (c) n = 2, l = 1, ml = 1, ms = +1/2 (d) n = 3, l = 1, ml = 0, ms = +1/2 (e) n = 4, l = 3, ml = 0, ms = -1/2 11. Which statement is false? (a) Cations are smaller than their corresponding neutral atom. (b) Anions are smaller than their corresponding neutral atom. 2+ (c) Mg 2- 2+ is larger than Be . - (d) O is larger than F . - - (e) Br is smaller than I . 12. Which element has an electron affinity greater than zero? 2 (e) l = 0, 1, 2, 3, 4 Chemistry 123 Exam 3 Harwood/Fall05 KEY (a) Br (b) I (c) Te (d) As (e) Kr 13. Which molecule contains a triple bond? (a) C2H4 (b) CCl4 (c) H2O (d) N2 (e) O2 14. Which bond is longest? (a) C-O (b) C-P (c) C-H (d) C-C (e) C-N 15. Which of the following represents a non-polar covalent bond ? (a) O-O (b) C-O (c) NaCl (d) C-N (e) C=O 2- 16. Which statement properly describes the formal charges on the atoms in SO4 ? (a) +2 on sulfur, -2 on oxygen (b) +2 on sulfur, -1 on oxygen (c) +1 on sulfur, -1 on oxygen (d) -1 on sulfur, +2 on oxygen (e) -2 on sulfur, 0 on oxygen 17. How many resonance forms will ozone, O3 have? (a) -1 (b) 0 (c) 1 (d) 2 (e) 3 18. Label the hybridization at C#1, C#2, C#3, and C#4 in the molecule. C1 C2 C3 C4 2 sp 3 sp sp sp 3 2 sp sp 3 (c) sp sp sp 2 sp sp (b) sp 2 sp sp d sp 3 (a) sp 2 sp 3 sp (d) sp (e) sp 3 3 2 3 3 19. Determine the hybridization around the central atom in KrF4. 2 (a) sp (b) sp 3 3 (c) sp (d) sp d 3 2 (e) sp d 20. For which of the following molecules will the electron-pair geometry be different than the molecular geometry? (a) NH4 + (b) CO (c) CH4 (d) BH3 3 (e) H2O

Exam3 Answer Key