AP CHEMISTRY CHAPTERS 5 & 6 Problem Set #4. (Questions 1-13) Choose the letter that best answers the question or completes the statement.

Transcription

1 NAME: AP CHEMISTRY CHAPTERS 5 & 6 Problem Set #4 (Questions 1-13) Choose the letter that best answers the question or completes the statement. (Questions 1-2) Consider atoms of the following elements. Assume that the atoms are in the ground state. A. S B. Ca C. Ga D. Sb E. Br The atom that contains exactly two unpaired electrons. The atom that contains only one electron in the highest occupied energy sublevel. Which one of the following does NOT exhibit resonance? A. SO 2 B. SO 3 C. HI D. CO 3 2- E. NO 3 - In which of the following is there polar double bonding in a nonpolar molecule? A. SO 2 B. SiH 4 C. CO 2 D. CaO E. NO The bond energy of Br-Br is 192 kj/mole, and that of Cl-Cl is 243 kj/mol. What is the approximate Cl-Br bond energy (in kj/mole)? A B. 109 C. 218 D. 435 E Types of hybridization exhibited by the C atoms in acetylene, C 2 H 2, include which of the following: I. sp II. sp 2 III. sp 3 A. I only B. III only C. I and II D. II and III E. I, II, and III 7. Which of the following diatomic molecules has the shortest bond length? A. Li 2 B. Be 2 C. B 2 D. N 2 E. O 2

2 8. In a molecule in which the central atom exhibits dsp 3 hybrid orbitals, the electron pair arrangements form the shape of a(n) A. tetrahedral B. square pyramidal C. trigonal bipyramidal D. square planar E. octahdral 9. On the periodic table, as the atomic number increases from 3 to 10, what happens to the atomic radius? A. It decreases only. B. It decreases, then increases. C. It remains constant. D. It increases only. E. It increases and then decreases. 10. IONIZATION ENERGIES FOR ELEMENT Qt (kj mol -1 ) First Second Third Fourth Fifth 634 2,178 3,296 5,780 17, 935 The ionization energies for element Qt are listed in the table above. On the basis of the data, element Qt is most likely to be A. K B. Ca C. Ga D. Ge E. As Which of the following elements has the lowest electronegativity? A. Na B. Mn C. Cr D. Zn E. Ag Which of the following elements has no unpaired electrons in its ground state? A. Na B. Mn C. Cr D. Zn E. Ag All of the following statements about the oxygen family of elements are true EXCEPT: A. The electron configuration of the valence electrons of each atom is ns 2 np 4. B. The ionization energy decreases with increasing atomic number. C. The atomic radii increase with increasing atomic number. D. The only oxidation states exhibited by members of this family are +2. E. It contains both metals and nonmetals

3 (Questions 14-15) Determine if the following have resonance structures. If it is determined to have resonance, draw all the resonance structures. 14. nitrate ion 15. sulfate ion 16. Draw the complete Lewis structure (electron-dot diagram) for each of the three following molecules: CF 4 ; PF 5 ; SF 4 a. What is the F-C-F bond angle in CF 4? b. What is the geometric shape formed by the atoms in SF 4? (Questions 17-18) Describe the hybridized bonding in the following: 17. I SiH 4

4 19. XeOF 2 : Draw the Lewis Dot structure and list the molecular geometric shape(s) and bond angle(s). Also determine if the molecule will have a dipole moment. If one is present, use the arrow method to draw the dipole onto the Lewis structure. 20. Is it possible to have a. a nonpolar molecule that is made of polar bonds? EXPLAIN YOUR ANSWER. b. a polar molecular that is made of nonpolar bonds? EXPLAIN YOUR ANSWER. 21. Arrange the following atoms in order of DECREASING electronegativity: F, I, Xe, K EXPLAIN YOUR ANSWER. (Questions 22-23) Write the electron configuration and draw the orbital diagram for the following atoms. Also, determine if it is paramagnetic or diamagnetic. 22. I 23. Ho

5 24. Using the bond energy values in the appendix of your notes, calculate H for the following reaction H 2 O 2 + CH 3 OH --- H 2 CO 3 + 2H 2 O 25. Draw the Lewis Dot structure for the following. ALSO DETERMINE VSEPR GEOMETRIC SHAPES AND BOND ANGLES for C 2 Cl 4 (Questions 26-27) For the following, draw the Lewis Dot structure. Then determine if the molecule is polar and if so SHOW the dipole moment using the arrow method. 26. ICl 27. NH 3 Use the following structure to answer questions 16-23:

6 28. How many carbon atoms are sp 3 hybridized? 29. How many carbon atoms are sp 2 hybridized? 30. Which atom is sp hybridized? 31. How many σ bonds are in the molecule? 32. How many π bonds are in the molecule? 33. What is the N-N-N bond angle? 34. What is the H-O-C bond angle in the side group attached to the five-membered ring? 35. What is the hybridization of the oxygen atom in the CH 2 OH group?