CHE 105 Final Exam Part A July 31, 2013

Transcription

1 CHE 105 Final Exam Part A July 31, 2013 University of Kentucky Department of Chemistry READ THESE DIRECTIONS CAREFULLY BEFORE STARTING THE EXAMINATION! It is extremely important that you fill in the answer sheet EXACTLY as indicated, otherwise your answer sheet may not be processed; ALL entries are to be made on SIDE 1 of the answer sheet. Use a #2 pencil (or softer); fill in the circles completely and firmly. Erasures must be complete. Use only the following categories: NAME: STUDENT NUMBER: TEST FORM: SPECIAL CODES: Print your name starting at the first space, LAST NAME first, then a space, followed by your FIRST NAME, then another space, followed by your MIDDLE INITIAL. Fill in the correct circles below your printed name corresponding to the letters of your name; for the spaces, fill in the top blank circle. This is VERY IMPORTANT! Under IDENTIFICATION NUMBER, put in your 8 DIGIT STUDENT ID NUMBER (do not use the 9 at the beginning of your number) beginning in column A and continuing through column H, column I will be blank, (do NOT use column J at this time); be sure to fill in the correct circles (a common error to be avoided is mistaking "0" for "1"). Fill in the "4" blank in the J column under IDENTIFICATION NUMBER (to indicate Examination IV). Use for course and section number; in positions K-P write in the following: Dr. Owen SIGNATURE: You MUST sign the examination answer sheet (bubble sheet) on the line directly above your printed name. Use your legal signature. Answering Questions: Starting with answer "1" on SIDE 1, fill in the circle indicating the one best answer for each of the 25 questions in this examination. Your score is the sum of the appropriate credit for each response. On the day following the examination, an examination key will be posted on Blackboard. Grading and Reporting: The examination scores will be posted in Blackboard as soon as possible after the examination. If an error has occurred in scoring your answers, inform your instructor within 48 hours of the posting of your score. BE SURE THAT YOUR TEST HAS 25 QUESTIONS, A PERIODIC TABLE, AND ONE SHEET OF SCRATCH PAPER. You may NOT use your own scratch paper during this examination. Cell phones, computers, and pagers are to be turned off and out of sight during the exam.

2 Questions 1-13 Exam 1 material (Chapter 1-3) 1. Which of the following statements best describe a chemical property? A. Ethanol is concentrated during distillation. B. Chromium metal is attracted to a magnetic field. C. Sodium sublimes to a gas during a Born-Haber process step. D. Acetic acid is neutralized by sodium hydroxide. 2. What is the answer to the following calculation using proper scientific notation and the appropriate number of significant figures? ( ) A C B D If an object has a density of g/cm 3, what is the density in μg/ml? A μg/ml C μg/ml B μg/ml D μg/ml 4. How long does it take light to travel ten parsecs? A parsec = meters. A years C years B years D years

3 5. How many protons, neutrons, and electrons are in the following compound? A. p = 35, n = 17, e = 17 C. p = 17, n = 18, e = 17 B. p = 17, n = 35, e = 17 D. p = 17, n = 18, e = Which of the following statements about isotopes is true? A. Isotopes of the same element do not have the same number of protons. B. Isotopes of the same element have the same mass. C. Some elements have 3 or more naturally occurring isotopes. D. Isotopes of the same element only differ in the number of electrons they contain. 7. Complete the following table: Atomic Number Mass Number Neutrons Atomic Symbol W = X = Y = Z = A. W = 321, X = U, Y = 72, Z = Sb B. W = 143, X = U, Y = 51, Z = Hf C. W = 143, X = U, Y = 51, Z =Sb D. W = 92, X = U, Y = 72, Z = Hf 8. How many moles are in 86.7 g of bromine? A moles C moles B moles D moles

4 9. How many atoms are in 92.5 g of fructose (C 6 H 12 O 6, molar mass = grams/mole)? A atoms C atoms B atoms D atoms 10. What is the mass percent of manganese in potassium permanganate (KMnO 4 )? A. 17.4% C. 52.1% B. 34.8% D. 45.7% 11. Selenium reacts with oxygen to form two different oxide compounds. If one of the oxide compounds is 37.8% oxygen by mass, what is the empirical formula of the compound? A. SeO C. SeO 2 B. SeO 3 D. Se 2 O What is the correct formula for aluminum sulfate? A. AlSO 4 C. AlSO 3 B. Al 2 S 2 O 8 D. Al 2 (SO 4 ) What is the correct name for IF 7? A. iodine fluoride C. moniodine fluoride B. iodide heptafluoride D. iodine heptafluoride

5 Questions Exam 2 material (Chapter 4-5) 14. How many grams of lithium nitride can be formed from 12.1 grams of lithium reacting with an excess of nitrogen? The molar mass of lithium nitride = g/mol. 6 Li(s) + N 2 (g) 2 Li 3 N(s) A grams C grams B grams D grams 15. How many grams of ZnS are produced when 315 ml of M ZnSO 4 react with 285 ml of M BaS? The molar mass of ZnS is g/mol. BaS(aq) + ZnSO 4 (aq) ZnS(s) + BaSO 4 (s) A g C g B g D g 16. Which compound is the most soluble in water? A. CaS C. CaSO 4 B. AgCl D. Ca 3 (PO 4 ) How much 2.00 M Ca(OH) 2 solution is required to neutralize 3.8 L of a 2.00 M HCl solution? A. 1.2 L C. 156 ml B. 1.9 L D. 2.6 L 18. The titration of 25.0 ml of sulfuric acid (H 2 SO 4 ) solution of unknown concentration requires 94.5 ml of 0.12 M LiOH to completely neutralize the acid. What is the concentration of the H 2 SO 4 solution? A M C M B M D M

6 19. What is the oxidation number of copper in CuNO 3? A. +1 C. +2 B. 1 D Identify the redox reaction(s) from the list below: I. 4 Li(s) + O 2 (g) 2 Li 2 O(s) II. Mg(s) + 2 HCl(aq) MgCl 2 (aq) + H 2 (g) III. Pb(NO 3 ) 2 (aq) + Na 2 SO 4 (aq) PbSO 4 (s) +2 NaNO 3 (aq) IV. NaCl(aq) + AgNO 3 (aq) AgCl(s) + NaNO 3 (aq) A. I C. I and II B. I, II, and III D. II, III, and IV 21. What is 1492 mm Hg in units of atm? A atm C atm B atm D atm 22. A fixed amount of gas occupies a volume of 10.0 L at a pressure of 667 torr. What is the volume when the pressure is increased by 179 torr at constant temperature? A L C L B L D L 23. What is the volume of 30.0 g of argon gas at 430 K and atm? A L C L B L D L

7 24. A g sample of gas occupies 125 ml at atm and 25 C. What is the molar mass of the gas? A g/mol C g/mol B g/mol D g/mol 25. How many grams of zinc metal are required to produce 2.00 L of hydrogen gas at STP according to the chemical equation shown below? Zn(s) + 2 HCl (aq) ZnCl 2 (aq) + H 2 (g) A g C g B g D g 26. A mixture of 18 g of neon and 25 g of krypton has a total pressure of 1.6 atm. What is the partial pressure of krypton? A atm C atm B atm D atm

8 Answer Key: 1. D 2. B 3. A 4. A 5. D 6. C 7. C 8. D 9. B 10. B 11. B 12. D 13. D 14. A 15. C 16. A 17. B 18. B 19. A 20. C 21. B 22. B 23. A 24. D 25. C 26. D