SUPeR Chemistry CH 222 Practice Exam

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1 SUPeR Chemistry CH 222 Practice Exam This exam has been designed to help you practice working multiple choice problems over the material that will be covered on the first CH 222 midterm. The actual exams for each section of CH 222 will be different and you should not assume that this practice exam is representative of those exams. To get the maximum benefit out of this practice exam, treat it like a real exam. Give yourself one hour to take the test and do not use any outside resources except your calculator and a periodic table. Do not stop during the exam to look up answers. When finished, grade yourself using the answer key.

2 SUPeR Chemistry Practice Exam Page 2 Multiple Choice Select the one best answer. 1. Based on electronegativity trends in the periodic table, predict which of the following compounds will have the greatest % ionic character in its bonds. A. KF B. CCl 4 C. CS 2 D. CO 2 E. ICl 2. Which type of chemical bonds holds the atoms together within a water molecule? A. ionic bond B. nonpolar covalent bond C. polar covalent bond D. metallic bond 3. The lattice energy for ionic crystals increases as the charge on the ions and the size of the ions. A. increases, decreases B. increases, increases C. decreases, increases D. decreases, decreases 4. The lattice energy for CaF 2 is the energy change for which one of the following processes? A. CaF 2 (g) Ca 2+ (s) + 2F - (g) B. CaF 2 (s) CaF 2 (g) C. CaF 2 (s) Ca(g) + 2F(g) D. CaF 2 (s) CaF 2 (aq) E. CaF 2 (s) Ca 2+ (g) + 2F - (g) 5. Which of the following bonds is the most polar? A. H Cl B. H S C. H C D. H F E. H O 6. Complete this statement to make it correct Elements with first ionization energies and electron affinities generally form cations. A. low, very negative B. high, positive or slightly negative C. low, positive or slightly negative D. high, very negative

3 SUPeR Chemistry Practice Exam Page 3 7. The BrCl molecule may be represented by the electronic formula Br Cl represented as The polarity is best A. δ δ C. δ+ δ+ B. δ+ δ D. δ δ+ 8. Which type of hybrid orbital is used by carbon in CO 2? A. sp B. sp 2 C. sp 3 D. sp 3 d E. spd 2 9. Calculate (in kj/mol) the standard enthalpy change ΔH for the formation of ammonia, as represented by the reaction written below. N 2 (g) + 3H 2 (g) 2NH 3 (g) Bond N N N=N N N H H N H Bond energy (kj/mol) A B C D. 204 E In which one of the following molecules/ions does the central atom have a formal charge of +2? A. SF 6 B. SO 4 2- C. O 3 D. BeCl 2 E. AlCl Which pair is geometrically similar? A. SO 2 and CO 2 C. CO 2 and OF 2 B. PH 3 and BF 3 D. SO 2 and O 3

4 SUPeR Chemistry Practice Exam Page The bond type and molecular polarity of BrF 5 are Bond Type Polarity of Molecule A. polar nonpolar B. polar polar C. nonpolar polar D. nonpolar nonpolar 13. The structure of the CO 3 2 ion can be described in the Lewis formulation by the structures 2 2 O O O C C C O O O O O O 2 which means that A. two CO bonds are single bonds, the third CO bond is a double bond. B. three independent forms of the CO 3 2 ion co-exist in equilibrium. C. the electrons must be rapidly exchanging among the three forms. D. the CO 3 2 ion exists in only one form which is a composite or average of the three principal structures shown. 14. Which of the following molecules is nonpolar? A. NH 3 B. OF 2 C. CH 2 Cl 2 D. H 2 O E. BeCl 2

5 SUPeR Chemistry Practice Exam Page What is the electron configuration of Fe 3+? A. [Ar] 3d 6 4s 2 D. [Ar] 3d 5 B. [Ar] 3d 3 4s 2 E. [Ar] 3d 6 C. [Ar] 3d 4 4s A white crystalline compound is quite soluble in water and gives a solution that conducts an electrical current. When melted, the molten state also conducts an electrical current. From this evidence the bonding is A. ionic C. polar covalent B. metallic D. non-polar covalent 17. Which of the following atoms has the lowest 2 nd ionization energy? A. F B. O C. Na D. Mg E. Li 18. What is the shape of the ClF 2 ion as predicted by the VSEPR theory? A. linear D. T-shaped B. bent E. trigonal planar C. see-saw 19. The approximate H C H bond angle in ethylene, H 2 CCH 2 is A. 60 B. 90 C. 109 D. 120 E Which of the following characteristics apply to the molecule BF 3? 1) trigonal planar molecular geometry 2) one unshared pair of electrons on B 3) sp 2 hybridized boron atom 4) polar molecule 5) polar bonds A. 2, 4, and 5 D. 1, 3 and 5 B. 1, 3 and 4 E. 3, 4 and 5 C. 1, 2 and 3

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