CHM101 Exams 1-3 Review Answer Key

CHM101 Exams 1-3 Review Potentially useful information: 1 inch = 2.54 cm (exactly) Activity Series 1 lb = 453.6 g 1 quart = 0.9464 L 4 quart = 1 gallon K = ºC + 273.15 Avogadro’s Number: 6.022 × 1023 E = hν (h = 6.626 × 10–34 J∙s) c = λν (c = 3.00 × 108 m/s) hc E=  109 nm = 1 m Gas pressure is inversely proportional to volume (P1V1 = P2V2) q = mCT (where q is heat, m is mass, C is specific heat, and T is change in temperature) Formulas of some common polyatomic ions: NO3–, HCO3–, CO32–, SO42–, PO43–, NH4+ All compounds containing any of the following are soluble: Na+, K+, Li+, NH4+, NO3–, CH3CO2– 1. Suppose the typical dose of epinephrine (at a particular concentration) administered to a patient under cardiac arrest is 0.1 milligram per kilogram of body weight. If a patient weighs 180 pounds, how much epinephrine should be administered? (Note: Possible answers are expressed to one significant figure.) A. 8 mg B. 20 mg C. 40 mg D. 8000 mg E. 8 × 106 mg 2. Which of the following statements regarding the nucleus of an atom is incorrect? A. B. C. D. E. The nucleus is the central core of the atom. The nucleus contains the electrons and the protons. The nucleus contains most of the mass of the atom. The nucleus contains the neutrons. The nucleus contains the neutrons and protons and most of the mass of the atom. 3. The isotope symbol for an ion that has 12 protons, 13 neutrons, and 10 electrons is: A. 13 12 Mg B. 13 12 Mg 2+ C. 25 12 Mg 2+ D. 25 12 Mg E. -1- 25 13 Al2+ 4. Which of these images represents a pure substance that is a compound? I. A. I B. II C. V II. III. IV. V. D. I and V E. I, IV, and V 5. If a balloon filled with helium were heated with a blow-dryer, the balloon would increase in volume. What would happen to the density of the helium in the balloon? A. B. C. D. E. The density would decrease. The density would increase. The density would remain the same. A chemical reaction would occur, so it is impossible to predict. The initial statement is incorrect. Helium is a very reactive element and would explode upon heating. 6. Which of the following statements regarding the figure is correct? Before A. B. C. D. E. After A chemical change occurs in which atoms rearrange to form a new compound. A chemical change occurs in which an ionic compound is formed from diatomic elements. A chemical change occurs in which no atoms rearrange to form a new substance. A physical change occurs in which no atoms rearrange to form a new substance. A physical change occurs in which atoms rearrange to form a new compound. 7. What is the correct name for Ca(NO3)2? A. B. C. D. E. calcium nitrite calcium nitrate calcium dinitride calcium(II) nitrite calcium nitride 8. How many sodium ions are in 245 g Na2SO4 (MM = 142.05 g/mol)? A. B. C. D. E. 1.72 Na+ ions 3.45 Na+ ions 2.86 × 10–24 Na+ ions 1.04 × 1024 Na+ ions 2.08 × 1024 Na+ ions -2- 9. Which of the following compounds is expected to have the highest melting point? A. H2O2 B. NO2 C. CH4 D. CO2 E. NaCl 10. Predict which of the following reactions will occur? (Hint: Consult the activity series on the front of the exam.) I. Ni(s) + FeCl2(aq)  NiCl2(aq) + Fe(s) II. 2Al(s) + 3NiCl2(aq)  2AlCl3(aq) + 3Ni(s) III. Fe(s) + CuCl2(aq)  FeCl2(aq) + Cu(s) A. I only B. II only C. III only D. II and III E. all three reactions will occur 11. When aqueous solutions of Pb(NO3)2 and KI are mixed a yellow solid forms. What is the net ionic equation for this reaction? A. B. C. D. E. K+(aq) + NO3–(aq) → KNO3(s) 2K+(aq) + (NO3–)2(aq) → K2(NO3)2(s) Pb(aq) + I(aq) → PbI(s) Pb2+(aq) + I–(aq) → PbI(s) Pb2+(aq) + 2I–(aq) → PbI2(s) 12. Calculate the molarity of a solution consisting of 240.0 g of NaOH (MM = 40.00 g/mol) in 2.50 L of solution. A. 0.266 M B. 0.66 M C. 2.40 M D. 6.00 M E. 15.00 M 13. Aluminum reacts with oxygen in a combination reaction to form aluminum oxide. What is the balanced equation for the reaction? A. B. C. D. E. Al(s) + O(g) → AlO(s) Al(s) + O2(g) → AlO2(s) 2Al(s) + 3O(g) → Al2O3(s) Al2(s) + O3(g) → Al2O3(s) 4Al(s) + 3O2(g) → 2Al2O3(s) 14. Iron metal reacts with chlorine gas according to the equation: 2Fe(s) + 3Cl2(g)  2FeCl3(s) If 35.0 g each of iron and chlorine react, how much FeCl3 (MM = 162.2 g/mol) will be formed? A. 53.4 g B. 68.0 g C. 80.0 g D. 102 g E. 155 g 15. Which of the following represents the electron configuration of As3−? A. [Ar4p3 B. [Ar]4s24p3 C. [Ar]3d104p3 D. [Ar]4s23d104p3 E. [Ar]4s23d104p6 -3- 16. Which of the following descriptions best describes the reaction shown in this image? A. B. C. D. E. A double-displacement reaction occurs between two molecular compounds. A single-displacement reaction occurs between two molecular compounds. A decomposition reaction occurs in which an ionic compound decomposes to form two nonmetals. A combination reaction occurs in which two nonmetals react to form a molecular compound. A combination reaction occurs in which a metal reacts with a nonmetal to form an ionic compound. 17. When 52.0 g of cold water was added to 75.0 g of water at 72.0 ºC, the final temperature was 35.0ºC. How much heat was gained by the cold water? (The specific heat of water is 4.184 J/g·ºC.) A. 37.0 J B. 3560 J C. 8050 J D. 11,600 J E. 19,700 J 18. Which of the following substances has both ionic and covalent bonding? A. NaCl B. Cl2 C. MgO D. NaNO3 E. SO2 19. Which of the following bonds is polar? A. H―H B. F―F C. Cl―Cl D. F―N E. P―P 20. Predict the molecular shape and give the approximate bond angle for the H2O molecule. A. B. C. D. E. linear, 180 trigonal planar, 120 tetrahedral, 120 trigonal pyramidal, 109.5 bent, 109.5 21. Identify the main group element, X, that could form the compound A. P B. B C. C D. F E. O 22. The volume of a given mass of gas is decreased from 5.0 L to 2.5 L. Which of the following best describes what will happen to the pressure of the gas? A. B. C. D. E. The pressure will remain the same. The pressure will decrease by a factor of two. The pressure will increase by a factor of two. The pressure will decrease by a factor of five. The pressure will increase by a factor of five. -4- CHM 101 Exams 1-3 Review Answers Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Answer A B C C A D B E E D E C E A E E D D D E A C  -5-