A. In the fifth period, electrons are being added to the 5s, 5p and 5d subshells. B. All IVA elements have four unpaired electrons in their ground state electron configurations. C. The representative elements of the fourth period have valence electron in the 4s and 3p subshells. D. Electrons are filling the 5d subshell for the transition elements of the sixth period.
2. The element whose electrons have the ground state electron configuration: [Kr]5s24d105p2 1. is in group IIA of the periodic table. 2. is a transition element. 3. bears a similarity in chemical properties to the element lead. 4. has two unpaired electrons.
A. 3 and 4 B. 2 and 3 C. 1 and 2 D. 1 and 4
3. Which of the following ground state electron configurations are correct ? 1. Cr [Ar]4s13d5 3. Se [Ar]4s23d104p4 2. Ga [Ar]4s24d104p1 4. Ni [Ar]4s13d10
A. 1 and 4 B. 1 and 3 C. 2 and 4 D. 2 and 3
4. An M3+ ion has the electron configuration [Xe]4f145d5. Therefore the ion must be
A. Os3+ B. Ta3+ C. Ru3+ D. Au3+
5. Which of the following pairs have the largest species listed first ? 1. S2-, S- 4. Rb+, Sr2+ 2. Fe3+, Fe 5. Cl-, Br- 3. Rb, Ca 6. S, As
A. 1, 4, and 5 B. 3 and 6 C. 1, 3, and 4 D. 2, 5, and 6
6. The third period element whose first through sixth ionization energies are respectively, (in kJ/mol) 786.3, 1580, 3230, 4360, 16,000, and 20,000, most likely is
A. S B. Al C. Si D. Cl
7. Which of the following statements are true ? 1. Na is more reactive than K. 3. Ca is more reactive than K. 2. Cl2 is more reactive than Br2. 4. Li is more reactive than Mg.
A. 2 and 4 B. 1 and 3 C. 2 and 3 D. 3 and 4
8. Which of the following are true ? 1. All of the halogens react with hydrogen to form hydrogen halides. 2. CaO is a superoxide. 3. Be readily reacts with water to form Be(OH)2. 4. Na forms a peroxide when reacted with oxygen while Li does not.
A. 2 and 3 B. 1 and 2 C. 3 and 4 D. 1 and 4
9. The first ionization energy of P(g) is 1012 kJ/mol. The electron affinity of P(g) is -72 kJ/mol. What is the energy change for:
P+(g) + P (g) ---> 2 P(g)
A. -1084 kJ B. -940 kJ C. 1084 kJ D. 940 kJ
10. Which of the following Lewis symbols are correct ?
A. 1 and 4 B. 2 and 4 C. 2 and 3 D. 1 and 3
11. The correct order of the following species from smallest to largest lattice energy is: NaF NaCl MgO MgCl2
smallest ---------------------- largest
A. NaCl < NaF < MgCl2 < MgO
B. MgO < NaCl < MgCl2 < NaF
C. NaF < NaCl < MgO < MgCl2
D. NaF < NaCl < MgCl2 < MgO
12. Which of the following Lewis structures are incorrect ?
A. 2 and 4 B. 2 and 3 C. 3 and 4 D. 1 and 2
13. The ClO2- ion has ________ single bonds, ________ double bonds, and ________ lone pairs for its Lewis structure.
A. two single bonds, no double bonds and eight lone pairs. B. one single bond, two double bonds and six lone pairs. C. three single bonds, no double bonds and six lone pairs. D. two single bonds, no double bonds and ten lone pairs.
14. Which one of the following oxides of chlorine does not obey the octet rule ?
A. Cl2O B. ClO2 C. Cl2O5 D. Cl2O3
15. In which one of the following structures does nitrogen have a formal charge of -2 ?
16. Which one of the following bonds is the most polar bond ?
A. C-S B. Na-F C. Na-Cl D. O-F
17. Calculate an approximate enthalpy change for the reaction of H2 and C2H2 to form one mole of H3C-CH3 using the necessary bond energies listed below. C-H 414 kJ/mol C-C 348 kJ/mol C=C 611 kJ/mol C-=C 837 kJ/mol H-H 436 kJ/mol
A. +9.25 x 102 kJ B. -7.31 x 102 kJ C. -2.95 x 102 kJ D. -5.21 x 102 kJ
18. Which of the following are correct geometries of the indicated molecule ? (The bolded atom is the central atom). 1. IF5, seesaw 3. H2CO, trigonal planar 2. BF3, trigonal pyramidal 4. CF4, tetrahedral
A. 1 and 2 B. All are correct. C. 1, 3 and 4 D. 3 and 4
19. Which of the following species would be expected to exhibit linear geometries ? 1. NH2- 2. CS2 3. I3- 4. NO2-
A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4
20. Which of the following species would be expected to have a non-zero dipole moment ? 1. NO 2. SO32- 3. ClO4- 4. XeF4
A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4
21. In which of the following molecules species is the hybridization of the indicated atom correctly given ?
A. All indicated hybridizations are correct. B. 1 only is correct. C. 1 and 2 only are correct. D. 1 and 3 only are correct.
22. The molecule N2O (N-N-O connectivity) has
A. two sigma bonds and no pi bonds. B. two sigma bonds and one pi bond. C. one sigma bond and two pi bonds. D. two sigma bonds and two pi bonds.
23. Which one of the following statements is true ?
A. One may never put electrons in antibonding orbitals. B. Molecular orbitals are formed by combining atomic orbitals on the same atom. C. In sigma bonding molecular orbitals, electron density is concentrated between the nuclei. D. Molecular orbital theory predicts that the He2 molecule has two unpaired electrons.
24. Which of the following are paramagnetic according to molecular orbital theory ? 1. C22- 2. N2 3. O2 4. B2
A. 1 and 2 B. 2 and 3 C. 3 and 4 D. 1 and 4
25. Which one of the following has a bond order of 2 ?
A. C2 B. B2 C. Li2 D. O22-