CHM 2045 F18 Test 3 Review Questions with answers PDF

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CHM 2045 F18

Test 3 Review Questions Form A

1. Determine the electron geometry (eg) and molecular geometry (mg) of SF4. A. eg=trigonal bipyramidal, mg=trigonal bipyramidal B. eg=tetrahedral, mg=tetrahedral C. eg=trigonal bipyramidal, mg=see-saw D. eg=octahedral, mg=trigonal bipyramidal E. eg=octahedral, mg=octahedral 2. How would you describe the molecular polarity of SeCl6? A. Nonpolar, because Se-Cl is a nonpolar bond and there is no lone pair on Se B. Nonpolar, because Se-Cl is a polar bond but the geometry is symmetric C. Polar, because Se-Cl is a polar bond although the geometry is symmetric D. Polar, because Se-Cl is a polar bond and there is a lone pair on Se E. Polar, because Se-Cl is a nonpolar bond but there is a lone pair on Se

3. What is the hybridization of the central atom in BrF5? A. sp

B. sp2

C. sp3

D. sp3d

E. sp3d2

4. Describe a pi bond. A. B. C. D. E.

s orbital overlapping with d orbital end to end overlap of two s orbitals p orbital overlapping with f orbital overlap of any two hybrid orbitals side by side overlap of two p orbitals

5. Consider the Lewis structure for formic acid (CO2H2). Determine the hybridization of the carbon atom. Then determine the total number of sigma (σ) and pi (π) bonds in the molecule. A. Carbon hybridization= sp3, 3 σ bonds; 2 π bonds B. Carbon hybridization= sp3, 4 σ bonds; 1 π bond C. Carbon hybridization= sp2, 4 σ bonds; 1 π bond D. Carbon hybridization= sp2, 3 σ bonds; 1 π bond E. Carbon hybridization= sp2, 3 σ bonds; 2 π bonds

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CHM 2045 F18

Test 3 Review Questions Form A 6. Place the following in order of increasing A-Se-A bond angle, where A represents the outer atoms in each molecule. Cl Cl F

Se

F

Cl Se

Cl

O

Se

O

Cl Cl

A. SeCl6 < SeF2 < SeO2 B. SeF2 < SeO2 < SeCl6 C. SeF2 < SeCl6 < SeO2 D. SeO2 < SeF2 < SeCl6 E. SeCl6 < SeO2 < SeF2

7. Consider an atom of Zirconium (Zr) where the electrons are in the ground state. How many electrons would be in orbitals that are spherical in shape? A. 2

B. 10

C. 17

D. 20

E. 25

8. Consider the portion of the orbital filling diagram below

Assuming each orbital is degenerate, which electron configuration could this correspond to? A. 2p

B. 2d

C. 3d

9. Choose the electron configuration for Cr3+. A. [Ar] B. [Ar]4s13d 2 C. [Ar]4s23d 6 D. [Ar]4s23d1 E. [Ar]3d 3

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D. 3f

E. 5s

CHM 2045 F18

Test 3 Review Questions Form A 10. Give the set of three quantum numbers that could represent the last electron added to the Sr atom. A. n = 5, l = 0, ml = 0 B. n = 4, l = 1, ml = 1 C. n = 5, l = 1, ml = 0 D. n = 4, l = 1, ml = -1 E. n = 5, l = 2, ml =1

11. Which element will have the largest first ionization energy? A. Ca

B. Mg

C. Be

D. Na

E. K

12. Consider the following substances, the central atom of which has to violate the octet rule to obtain the best Lewis structure? A. N2

B. NH4+

C. CF4

D. H2O

E. XeO3

13. The atomic radius of main-group elements generally increases down a column because____. A. B. C. D. E.

effective nuclear charge decreases down a column the mass of an atom increases down a column the highest principal quantum number of the valence orbitals increases effective nuclear charge increases down a column both effective nuclear charge increases down a column and the principal quantum number of the valence orbitals increases

14. Choose the best Lewis structure for OCl2. A.

B.

C.

D.

E.

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CHM 2045 F18

Test 3 Review Questions Form A 15. By using Born Haber cycle for the formation of silver chloride (AgCl), calculate the lattice energy of silver chloride in kJ from the following data:  Sublimation of Ag(s): 284 kJ  1st ionization energy of Ag(g): 731 kJ  Bond energy of Cl2(g): 244 kJ  1st electron affinity of Cl(g): −349 kJ  Enthalpy of formation of AgCl(s): −127 kJ A. 661

B. −783

C. −915

D. −1037

E. −1676

16. Place the following compounds in order of decreasing magnitude of lattice energy. K2O Rb2S Li2O A. K2O > Li2O > Rb2S B. Rb2S > K2O > Li2O C. Rb2S > Li2O > K2O D. Li2O > Rb2S > K2O E. Li2O > K2O > Rb2S 17. Choose the covalent bond that is the shortest. A. C‒N

B. O≡N

C. O=N

D. C≡N

E. C=N

18. Which of the following statements is TRUE? A. An orbital that penetrates into the region occupied by core electrons is less shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy. B. An orbital that penetrates into the region occupied by core electrons is more shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy. C. It is possible for two electrons in the same atom to have identical values for all four quantum numbers. D. Two electrons in the same orbital can have the same spin. E. None of the above are true.

19. Which two elements have the same ground-state electron configuration?

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CHM 2045 F18

Test 3 Review Questions Form A

A. Cl and Ar B. Cu and Ag C. Pd and Pt D. Fe and Cu E. No two elements have the same ground-state electron configuration.

20. For the successive ionization of an atom of Nitrogen, where would the first large increase in ionization energy be observed? A. B. C. D. E.

Between E1 and E2 Between E2 and E3 Between E4 and E5 Between E5 and E6 Between E7 and E8

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