CHEM 101 Fall 09 Exam 1 (a) On the answer sheet (scantron) write your name, student ID number, and recitation section number. Choose the best (most correct) answer for each question and enter it on your answer sheet. 1. Please choose the letter a as your answer for this question. Potentially useful data: Avogadro s number: 6.022 x 10 23 Speed of light: c = 3.00 x 10 8 m/s Planck constant: h = 6.626 x 10-34 J s E = hc/λ = hν 2. All of the following properties of a substance can aid in its identification except: a. density. b. temperature. c. reactivity. d. melting point. e. boiling point. 3. Which of the following is a chemical property of iron? a. Iron conducts heat. b. Iron conducts electricity. c. Iron melts at 1535 C. d. Iron can be bent into shapes. e. Iron rusts on exposure to water and oxygen. 4. Which is the best definition of a pure substance? a. A material that contains two or more types of atoms. b. A material in the gas phase. c. A material whose properties cannot be changed by further physical separation. d. A material whose properties have been measured. e. A material that has been heated. 5. All atoms of a given element are chemically identical. This is an example of: a. The Law of Conservation of Mass. b. Dalton's Atomic Theory. c. The Law of Constant Composition. d. The Law of Multiple Proportions. e. The Law of Conservation of Energy. Page 1 of 5
6. The Millikan oil drop experiment was used to determine a. whether the atom was radioactive. b. the electron distribution in the atom. c. the atomic number of an atom. d. the charge of an electron. e. the nuclear character of the atom. 7. Calculate the number of grams in 0.928 moles of nitrogen molecules (N 2 ). a. 14.0 g b. 28.0 g c. 13.0 g d. 26.0 g e. 30.2 g 8. How many grams of argon (Ar) contain the same number of atoms as 27 g of aluminum (Al)? a. 18 g b. 27 g c. 31 g d. 40 g e. 67 g 9. How many hydrogen atoms are in a 27.0 g sample of water (H 2 O)? a. 1.50 b. 2.99 c. 4.98 10-24 d. 1.81 10 24 e. 2.93 10 26 10. Which sample contains the greatest number of atoms? a. 50 g Ba b. 50 g Br c. 50 g Ca d. 50 g Ti e. 50 g P 11. Which element can be classified as a transition metal? a. Ar b. N c. F d. Co e. Rb Page 2 of 5
12. Which of the following is not an ionic compound? a. TiO 2 b. KMnO 4 c. CH 4 d. Na 2 SO 3 e. Ca(CH 3 COO) 2 13. What are the products of the dissolution of NaH 2 PO 4 (s) in water? a. NaH 2 3+ + PO 4 3- b. Na + + 2H + + P + 4O 2- c. Na + + H 2 + P + 2O 2 d. Na + + H 2 PO 4 - e. Na + + H + + P + O 4 2-14. Determine the number of molecules in 325 mg of aspirin, C 9 H 8 O 4. a. 1.81 10-3 b. 1.09 10 21 c. 3.34 10 23 d. 1.09 10 24 e. 3.34 10 26 15. In the reaction given below, how many grams of sodium metal are consumed if 2.02 g of hydrogen gas are produced? 2 Na(s) + 2 H 2 O(l) 2 NaOH(aq) + H 2 (g) a. 92.0 g b. 5.75 g c. 11.5 g d. 23.0 g e. 46.0 g 16. Classify the following reaction. 2 Al(s) + 3 CuSO 4 (aq) Al 2 (SO 4 ) 3 (aq) + 3 Cu(s) a. combination b. decomposition c. combustion d. dissolution e. displacement Page 3 of 5
17. The Roman numerals in the reaction given represent the coefficients in the balanced chemical equation. What are the values of the coefficients? I II III IV a. 1 2 1 2 b. 1 3 1 2 c. 2 3 2 4 d. 2 5 2 2 e. 4 6 4 8 I CH 3 OH + II O 2 III CO 2 + IV H 2 O 18. How many moles of ammonia will be formed from the complete reaction of 45.0 g of H 2? N 2 + 3 H 2 2 NH 3 a. 11.1 mol b. 14.9 mol c. 16.7 mol d. 7.43 mol e. 22.3 mol 19. How many grams of MgI 2 are produced by the reaction of 25.0 g of Mg with 25.0 g of I 2? Mg + I 2 MgI 2 a. 9.20 g b. 18.4 g c. 27.4 g d. 49.0 g e. 195 g 20. Which substance gets reduced in the reaction below? Na 2 SO 4 + 4 C Na 2 S + 4 CO a. CO b. C c. Na 2 S d. Na 2 SO 4 e. this is not an oxidation-reduction reaction 21. What is the oxidation number of P in PO 4 3-? a. +5 b. +3 c. -2 d. -3 e. -5 Page 4 of 5
22. Which of the following reactions are oxidation reduction reactions? I) Ca + 2 H 2 O Ca(OH) 2 + H 2 II) CaO + H 2 O Ca(OH) 2 III) Ca(OH) 2 + H 3 PO 4 Ca 3 (PO 4 ) 2 + H 2 O IV) Cl 2 + 2 KBr Br 2 + 2 KCl a. I and II b. II and III c. I and IV d. III and IV e. I and III 23. Determine the volume of solution that contains 15.0 g of AgNO 3 if the solution is 0.375 M. a. 31.5 ml b. 33.1 ml c. 235 ml d. 447 ml e. 956 ml 24. Dental lasers are based on neodymium yttrium aluminum garnet (Nd-YAG) crystal, with an emission wavelength of 1066 nm. What is the frequency of this laser? a. 2.81 10 5 Hz b. 2.81 10 14 Hz c. 3.20 10 18 Hz d. 3.20 10 2 Hz e. 3.55 10-15 Hz 25. Which statement below is false? a. The wavelength of light is the distance between two corresponding points in the wave pattern. b. The frequency of light is the number of waves that pass a given point in a second. c. The frequency of light increases as wavelength decreases. d. The higher the frequency of light, the greater its energy. e. The higher the frequency of light, the longer the wavelength. 26. Of the following, radiation has the longest wavelength and radiation has the greatest energy. gamma ultraviolet visible a. ultraviolet, gamma b. visible, ultraviolet c. gamma, gamma d. visible, gamma e. gamma, visible Page 5 of 5
CHEM101 Exam 1 Answer Section MULTIPLE CHOICE 1. ANS: A PTS: 0 2. ANS: B PTS: 1 3. ANS: E PTS: 1 4. ANS: C PTS: 1 5. ANS: B PTS: 1 6. ANS: D PTS: 1 7. ANS: D PTS: 1 8. ANS: D PTS: 1 9. ANS: D PTS: 1 10. ANS: E PTS: 1 11. ANS: D PTS: 1 12. ANS: C PTS: 1 13. ANS: D PTS: 1 14. ANS: B PTS: 1 15. ANS: E PTS: 1 16. ANS: E PTS: 1 17. ANS: C PTS: 1 18. ANS: B PTS: 1 19. ANS: C PTS: 1 20. ANS: D PTS: 1 21. ANS: A PTS: 1 22. ANS: C PTS: 1 23. ANS: C PTS: 1 24. ANS: B PTS: 1 25. ANS: E PTS: 1 26. ANS: D PTS: 1 Page 6 of 5