CHEMISTRY 110 EXAM 1 SEPTEMBER 20, 2010 FORM A 1. What are the correct numbers of protons, neutrons and electrons in a 39 K + ion? p n e A. 20 19 18 B. 20 19 19 C. 19 20 18 D. 19 20 19 E. 20 19 20 2. Which set of quantum numbers is not permissible for an electron in an atom? A. n = 6, = 1, m = 0 B. n = 3, = 2, m = 3 C. n = 3, = 2, m = 2 D. n = 1, = 0, m = 0 E. n = 4, = 3, m = 3
3. Of the atoms below, which one is the most electronegative? A. Si B. Cl C. Rb D. Ca E. S 4. Which of the following ionization processes requires the most energy? A. He He + + e B. Be Be + + e C. Na Na + + e D. Mg Mg + + e E. Fe Fe + + e 5. Which of the following statements is true? A. Ultraviolet light has a longer wavelength than infrared. B. Red light has a higher frequency than blue light. C. The wavelength of visible light is directly proportional to its frequency. D. X-ray has lower energy than microwave. E. Radio waves have a longer wavelength than visible light.
6. Which of the following could be an orbital diagram for a neutral carbon atom in an excited state? 1s 2s 2p A. ( ) ( ) ( ) ( ) ( ) B. ( ) ( ) ( ) ( ) ( ) C. ( ) ( ) ( ) ( ) ( ) D. ( ) ( ) ( ) ( ) ( ) E. ( ) ( ) ( ) ( ) ( ) 7. How many electrons have the quantum number m = 0 in the ground-state electron configuration of neon (Ne)? A. 2 B. 4 C. 6 D. 8 E. 10 8. What is the energy change when an electron in a hydrogen atom is promoted from n = 2 to n = 5? A. 276 kj B. 6.45 10 19 J C. 6.45 10 19 J D. 4.58 10 19 J E. 4.58 10 19 J
9. Consider the highest energy electron in the ground-state electron configuration of barium (Ba). Identify the shape of the orbital occupied by this electron. A. B. C. D. E. 10. How many unpaired electrons are there in the ground-state electron configuration of Co? A. 1 B. 2 C. 3 D. 4 E. 5
11. All orbitals in a given subshell have the same value(s) of the. i. quantum number n ii. quantum number iii. quantum number m iv. energy A. iii and iv B. i, ii, and iii C. i and ii D. ii and iv E. i, ii, and iv 12. Which one of the following is a true statement? A. Electronegativity is the ability of an atom in a molecule to lose electrons. B. Electron pairs are shared equally in a polar covalent bond. C. Transition metals lose their valence d electrons before valence s electrons. D. The effective nuclear charge increases as we move to the right across any row of the periodic table. E. Electron pairs are shared between atoms in an ionic bond.
13. Arrange the ions Te 2, I, Rb +, and Sr 2+ in order of decreasing size. A. Sr 2+ > Rb + > I > Te 2 B. I > Rb + > Te 2 > Sr 2+ C. Te 2 > I > Rb + > Sr 2+ D. Te 2 > Sr 2+ > I > Rb + E. Rb + > Sr 2+ > I > Te 2 14. In which of the following subshells of a Bi atom does an electron experience the greatest effective nuclear charge? A. 3f B. 3p C. 3d D. 3s E. 4s 15. Which one of the following elements has the most negative electron affinity? A. Na B. Mg C. S D. Cl E. Ne Go on to the next page
16. Element M reacts with chlorine to form a compound with the formula MCl 2. Element M is more reactive than magnesium and has a smaller radius than barium. Which one of the following can be element M? A. Sr B. K C. Na D. Ra E. Be 17. What is the ground-state electron configuration for the Fe 2+ ion? A. [Ar] 3d 6 B. [Ar] 4s 2 3d 4 C. [Ar] 3d 8 D. [Ar] 4s 2 3d 8 E. [Ar] 4s 2 3d 6 18. What is the formal charge on nitrogen in the best Lewis structures for the nitrate anion, NO 3? A. 1 B. 0 C. +1 D. +2 E. 2
----------------------------------------------------------------------------------------19. Which of the following is the best Lewis structure for ICl4? A. B. C. D. E. ----------------------------------------------------------------------------------------Go on to the next page
20. How many nonbonding electron pairs are on N and C in the Lewis structure of HCN (H bonded to C)? Nonbonding electron pairs on C N A. 0 1 B. 1 0 C. 1 1 D. 1 2 E. 2 1 21. List the following subshells found in a neutral many-electron atom in order of increasing electron energy. 4s, 3s, 4p, 3d, 5s A. 5s < 4s < 3s < 4p < 3d B. 3s < 3d < 4s < 4p < 5s C. 3s = 3d < 4s = 4p < 5s D. 3s < 4s < 3d < 5s < 4p E. 3s < 4s < 3d < 4p < 5s
22. The energy level diagram for a hypothetical one-electron atom is shown below. Which energy level represents the ground state and which transition corresponds to emission of light with the longest wavelength? A. ground state is E, transition is A E B. ground state is A, transition is A B C. ground state is E, transition is B C D. ground state is E, transition is D E E. ground state is A, transition is E A Go on to the next page
23. What is the frequency of the wave shown below assuming it is light (electromagnetic radiation)? A. 3.8 10 15 s 1 B. 0.19 s 1 C. 3.8 10 14 s 1 D. 1.9 10 14 s 1 E. 1.1 10 19 s 1 24. The energy of a pulse of green light (λ= 532 nm) is 1.92 10 3 J. How many photons are in the pulse? A. 3.63 10 3 B. 5.21 10 3 C. 5.14 10 15 D. 1.16 10 21 E. 1.57 10 24
25. Cl in nature is composed of two isotopes of 35 Cl (34.969 amu) and 37 Cl (36.966 amu). Based on the average mass of Cl, 35.453 amu, what is the content of 35 Cl in natural Cl? A. 24% B. 32% C. 68% D. 76% E. 132% 26. Which of the following ions can be drawn with only two equivalent resonance structures? (i) NO 2 (ii) NO 3 (iii) SO 3 2 (iv) BrO 3 A. (i) only B. (ii) only C. (ii) and (iii) D. (i) and (ii) E. (iv) Go on to the last page
27. Rank the following ions in order of decreasing N-O bond length: NO + NO 2 NO 3 A. NO + > NO 2 B. NO 3 > NO 2 C. NO 3 = NO 2 D. NO + > NO 3 E. NO + > NO 2 > NO 3 > NO + > NO + > NO 2 = NO 3 28. Which one of the following will have the largest lattice energy? A. TiF 2 B. TiCl 2 C. TiF 3 D. TiCl 3 E. TiCl 4 End of Test
FORM A 1. C 2. B 3. B 4. A 5. E 6. B 7. C 8. E 9. A 10. C 11. E 12. D 13. C 14. D 15. D 16. A 17. A 18. C 19. A 20. A 21. E or B 22. C 23. A 24. C 25. D 26. A 27. B 28. E CHEMISTRY 110 EXAM 1 SEPTEMBER 20, 2010 Answer Key