FAILING TO BUBBLE EVERYTHING CORRECTLY WILL PREVENT OR SIGNIFICANTLY DELAY PROCESSING OF YOUR EXAM!!

Transcription

1 Name Bubble on your scan sheet the Test Number and Test Form shown on the next page!! Principles of Chemistry I 3150: EXAM II Tuesday, 5:45PM October 30, 2018 Instructions: 1. Each student is responsible for following instructions. Read this page carefully pts. 2. Print your name on above. SIGN YOUR NAME on the scan sheet. Your signature on the scan sheet states your agreement with the following statement: I certify that I have not given or received aid on this exam, and that all work on the exam is entirely my own. 3. CODE your name (LAST NAME FIRST) on the computer answer sheet using an ordinary (No. 2 or HB) pencil. (No. 1 is also acceptable; No. 2½ or 3 is not.) It is very important to code the information correctly!! Use your full name as it is in UA s records, not any nickname. Fill as much of each name as will fit. 4. Put all calculations on the examination pages or scratch paper. Do not make any extra marks on the computer answer sheet!! 5. This exam consists of 35 multiple-choice questions worth 6 points each. For each multiple-choice question, choose the ONE best or correct answer and both write it on your exam paper and bubble it on the answer sheet. The computer answer sheet is the only one that will be graded! 6. Sorry, no answer to a question provided this time but keep reading the fine print in the future. Meanwhile, just remember: van der Waals is a gas law; van de Kamp s is fish sticks. 7. Unless otherwise stated in a question: atoms and molecules are in the ground state; solutions are aqueous; and substances are at 25 C and 1 atm (~100 kpa). 8. This exam booklet consists of 7 pages (including this one), a Periodic Table/Formula Sheet, and a sheet of blank paper. Please check to be sure that you have them all! KEEP YOUR EXAM BOOKLET AND ANSWER SHEET COVERED TO PROTECT THE INTEGRITY OF YOUR WORK! PROHIBITED DURING EXAM: cell phones, pagers, laptops, PDAs, headphones, hats worn low over the eyes Please put these items away until you have left the room. REALLY, REALLY important information about bubbling your scan sheet: You MUST use a No. 2 pencil to bubble your answer sheet. Sheets completed in ink can not and WILL NOT BE GRADED. Enter your first and last names as far to the LEFT as possible in the fields. WRITE the letters of your name in the boxes at the top of the columns. (Dr. Donovan can not read bubbles.) In the STUDENT ID field, enter two zeros, then your 7-digit UA ID number. (if your ID number has fewer than 7 digits, fill with zeros so that your number is as far to the right as it can go.) That is, enter ID Number as You MUST bubble 3150: in the Dept/Course/Section fields. You MUST bubble the TEST NUMBER AND TEST FORM shown above. FAILING TO BUBBLE EVERYTHING CORRECTLY WILL PREVENT OR SIGNIFICANTLY DELAY PROCESSING OF YOUR EXAM!! If you erase and change an answer, please try using the white plastic eraser at the front of the room to remove the old mark. The scanner is VERY sensitive to erased marks! Thanks. The Management Warning!!! Doing any of the following will result in earning a score of zero (0) for this test. using INK to complete the bubble sheet not entering your name on the answer sheet not signing your name to the answer sheet not entering the TEST NUMBER and TEST FORM as noted above

2 1A (1) 1 H Li Na K Rb Cs Fr (223) 2A (2) 4 Be Mg Ca Sr Ba Ra [226] 3B (3) 21 Sc Y Lu Lr (262) 4B (4) 22 Ti Zr Hf Rf (267) Activity Series of Metals Li(s) Li + (aq) + e K(s) K + (aq) + e Ba(s) Ba 2+ (aq) + 2e Ca(s) Ca 2+ (aq) + 2e Na(s) Na + (aq) + e Mg(s) Mg 2+ (aq) + 2e Al(s) Al 3+ (aq) + 3e Mn(s) Mn 2+ (aq) + 2e Zn(s) Zn 2+ (aq) + 2e Cr(s) Cr 3+ (aq) + 3e Fe(s) Fe 2+ (aq) + 2e Co(s) Co 2+ (aq) + 2e Ni(s) Ni 2+ (aq) + 2e Sn(s) Sn 2+ (aq) + 2e Pb(s) Pb 2+ (aq) + 2e H 2 (g) 2H + (aq) + 2e Cu(s) Cu 2+ (aq) + 2e Ag(s) Ag + (aq) + e Hg(l) Hg 2+ (aq) + 2e Pt(s) Pt 2+ (aq) + 2e Au(s) Au 3+ (aq) + 3e 57 La Ac [227] 5B (5) 23 V Nb Ta Db (268) 58 Ce Th INCREASING ACTIVITY 6B (6) 24 Cr Mo W Sg (271) 59 Pr Pa B (7) (8) Mn Fe Tc (98) 75 Re Bh (270) 60 Nd U Ru Os Hs (269) 61 Pm (145) 93 Np [237] N A = B (9) (10) Co Ni Rh Ir Mt (278) 62 Sm Pu (244) 46 Pd Pt Ds (281) 63 Eu Am (243) 1B (11) 29 Cu Ag Au Rg (281) 64 Gd Cm (247) 2B (12) 30 Zn Cd Hg Cn (285) 65 Tb Bk (247) 3A (13) 5 B Al Ga In Tl Nh (286) 66 Dy Cf (251) 4A (14) 6 C Si Ge Sn Pb Fl (289) 67 Ho Es (252) 5A (15) 7 N P As Sb Bi Mc (289) 68 Er Fm (257) 6A (16) 8 O S Se Te Po (209) 116 Lv (293) 69 Tm Md (258) 7A (17) 9 F Cl Br I At (210) 117 Ts (294) 70 Yb No (259) 8A (18) 2 He Ne Ar Kr Xe Rn (222) 118 Og (294) Note: notation such as g mol 1 is read grams per mole. T K = T C T F = 9 5 T C + 32 T C = 5 9 [T F 32] E = q + w q = mc T w = P V H = E + P V H = n H F (products) n H F (reactants) M 1 V 1 = M 2 V 2 H = nd(bonds broken) nd(bonds formed) M = mol/l 1 1 cal = J specific heat of water = J g 1 K h = J s c = m s 1 R H = J 1 c = ν E = hν E RH 2 n PV = nrt D = P RT M 1 1 r r n A B P V T = P V 2 2 T 1 2 B M M 1 R = L atm mol 1 K 1 atm 760 torr = 760. mmhg = kpa = 14.7 psi = mbar P i = X i P T P T = P i P 1 /P T = n 1 /n T 1 in 2.54 cm (exact) actual % yield = 100% BO = 1 theoretical 2 [#bonding e #antibonding * e ] A

3 Before going any further, enter TEST NUMBER 12 and TEST FORM B on your answer sheet. 1. Soluble metal hydroxides are (A) strong bases. (B) weak acids. (C) strong acids. (D) weak bases. 2. What are the primary products of the reaction of C 8 H 16 with excess O 2? (A) CO and H 2 O (B) CO and H 2 (C) CO 2 and H 2 O (D) CO 2 and H 2 (E) C, H 2, and CO 3. The products of a reaction have stronger bonds overall than the reactants. The reaction would be (A) endothermic. (B) exothermic. (C) impossible to predict in enthalpy. 4. Which metal(s) would react with a solution of Cr(NO 3 ) 3 in a redox displacement reaction? (A) Pt (B) Fe (C) both Pt and Fe (D) neither Pt nor Fe 5. Which gas sample would deviate the most from ideal behavior? (A) NO(g) at STP (B) NO(g) at 0 C, 100 atm (C) SO 2 (g) at STP (D) SO 2 (g) at 0 C, 100 atm 6. What is the oxidation number of nitrogen in the following, respectively? N 2 H 4, NCl 3, HN 2 O 2 (A) 2, +3, (B) +2, 3, +1 (C) 2, +3, +1 (D) +2, +3, +1 (E) +2, +3, 1 7. Which is correct for this reaction? Sn Cl Cl 2 + Sn oxidized reduced oxidizing agent reducing agent (A) Cl Sn 2+ Sn 2+ Cl (B) Sn 2+ Cl Cl Sn 2+ (C) Cl Sn 2+ Cl Sn 2+ (D) Sn 2+ Cl Sn 2+ Cl 8. Which ions would not precipitate when solutions of AgNO 3, BaBr 2, and Li 2 SO 4 are mixed together? (A) Ag +, Br, Li +, and NO 3 (B) Ba 2+, SO 4 2, Li +, and NO 3 (C) Ba 2+ and NO 3 (D) Li + and NO 3 (E) Li + and SO : Exam II 2 10/30/18

4 9. Which salt is formed by the reaction of a strong base with a weak acid? (A) ammonium nitrate (B) lithium phosphate (C) ammonium acetate (D) lithium chloride 10. What is the net ionic equation for the aqueous reaction of HF with NH 3? (A) F (aq) + NH + 4 (aq) NH 4 F(aq) (B) H + (aq) + OH (aq) H 2 O(l) (C) HF(aq) + OH (aq) F (aq) + H 2 O(l) (D) H + (aq) + NH 3 (aq) NH + 4 (aq) (E) HF(aq) + NH 3 (aq) NH + 4 (aq) + F (aq) Which reaction(s) would produce a gas among the products? I. CH 3 COOH(aq) + NaOH(aq) products II. H 2 SO 4 (aq) + Na 2 CO 3 (aq) products III. H 3 PO 4 (aq) + Na 2 SO 3 (aq) products (A) I only. (B) II only. (C) III only. (D) II and III. (E) I, II, and III. A polyatomic ion you were not required to learn is caprylate ion, C 7 H 15 COO. Knowing this, what is the name of C 7 H 15 COOH? (A) hydrocaprylate acid (B) caprylic acid (C) caprylous acid (D) hydrocaprylic acid (E) hydrogen caprylate ion What is the net ionic equation when solutions of CuNO 3 and CaCl 2 are mixed? (A) Cu + (aq) + Cl (aq) CuCl(s) (B) Ca 2+ (aq) + 2NO 3 (aq) Ca(NO 3 ) 2 (s) (C) 2Cu + (aq) + 2Cl (aq) + Ca 2+ (aq) + 2NO 3 (aq) Ca(NO 3 ) 2 (s) + 2CuCl(s) (D) there is no net ionic equation because no reaction occurs. The graph shows the distribution of molecular speeds of neon gas at two temperatures. Which curve describes the behavior of neon at the cooler temperature? (A) Curve 1 (B) Curve 2 (C) More information is required to solve this problem. What is the density (in g L 1 ) of CH 4 (g) at 14 C and 725 torr? (A) 0.65 g L 1 (B) 4.0 g L 1 (C) 13 g L 1 (D) 490 g L 1 (E) 10,100 g L 1 Molar Mass/g mol 1 CH : Exam II 3 10/30/18

5 Believe it or not, Dr. Donovan is on the Cleveland Indians cycling team for VeloSano to support cancer research (53 miles on July 21 without collapsing or even cramping up!). What is the final temperature (in C) of the air inside his tires, if the air inside started at 22.0 C and increased from 114 psi to 119 psi total pressure, assuming the volume of the tire did not change? (A) 34.9 C (B) 23.0 C (C) 22.0 C (D) 21.1 C (E) 9.6 C Which pressure is lowest? (A) 2.56 atm (B) 2260 torr (C) 31.4 psi (D) 263 kpa If the volume of a gas sample were doubled at constant temperature, the pressure would (A) remain constant. (B) be halved. (C) be doubled. (D) be squared. Under what conditions would NO(g) have the highest density? (A) low temperature, high pressure (B) low temperature, low pressure (C) high temperature, high pressure (D) high temperature, low pressure Consider two one-liter flasks: one contains N 2 gas at STP and the other contains C 3 H 8 gas at STP. Which quantity/quantities would be the same between the two flasks? I. density of gas II. average kinetic energy of gas molecules (A) I only. (B) II only. (C) both I and II. (D) neither I nor II. A process absorbs 22 kj of heat while it does 77 kj of work. What is E for this process? (A) 99 kj (B) 55 kj (C) +55 kj (D) +99 kj (E) none of these What would have to be done to the temperature (in K) of a sample of fixed moles of gas to keep its pressure constant if its volume were doubled? (A) The temperature would have to be kept constant. (B) The temperature would have to be be halved. (C) The temperature would have to be be doubled. (D) The temperature would have to be be squared. 3150: Exam II 4 10/30/18

6 23. What is the partial pressure of O 3 (in torr) in a mixture of 96 g O 3 (g) and 36 g He(g) that has a total pressure of 1.58 atm? (A) 218 torr (B) 327 torr (C) 600 torr (D) 874 torr (E) 982 torr For Questions 24-25, answer (A) for True or (B) for False. 24. The enthalpy of this reaction equals ΔH COMB for C 3 H 6 (g): 2C 3 H 6 (g) + 9O 2 (g) 6CO 2 (g) + 6H 2 O(l). 25. This reaction is expected to occur: PCl 5 + Cl 2 PCl ΔH for a chemical reaction results primarily from the difference in the in the products versus the reactants. (A) numbers of protons and neutrons (B) number of atoms (C) strengths of the chemical bonds (D) amount of heat Which is/are NOT state functions? I. enthalpy ( H) II. work (w) III. heat (q) (A) II and III only (B) I and III only (C) I only (D) I, II, and III (E) none of these The heat of fusion of dimethyl ether is +4.9 kj. Which value is reasonable for the heat of vaporization of dimethyl ether? (A) 22.4 kj (B) 3.7 kj (C) +4.2 kj (D) kj Use bond enthalpies to estimate ΔH for the following gas-phase reaction: (A) 91 kj (B) 37 kj (C) +37 kj (D) +91 kj (E) +651 kj Bond Enthalpies/kJ mol 1 CH 413 OH 467 CCl 339 CC 347 C=C 614 CO : Exam II 5 10/30/18

7 The van der Waals equation is shown. Which statement(s) must be TRUE about the van der Waals equation? 2 n a P + 2 V n b = nrt V I. a = 0 and b = 0 for an ideal gas. II. The term added to P adjusts for intermolecular attractions. (A) I only. (B) II only. (C) I and II. (D) Neither I nor II. If 44 ml of O 2 at STP were used, how many ml of N 2 at STP would be used? N 2 (g) + 2O 2 (g) + F 2 (g) 2NO 2 F(g) (A) 11 ml (B) 22 ml (C) 44 ml (D) 88 ml (E) It is impossible to tell without additional information. A scientist (not wearing a powdered wig) measured the volume of gas samples at constant pressure and temperature. Which set of data are most likely incorrect? Amount of gas/mol Volume/mL (A) (B) ,000 (C) ,000 (D) ,000 (E) ,000 Which graph best shows the relationship between volume and temperature of an ideal gas at constant pressure? V V V T T T (A) (B) (C) 34. What volume would be occupied by g of neon at 10.0 C and 1.06 atm? (A) 7.74 L (B) 22.4 L (C) 156 L (D) 219 L (E) 4420 L Continue reading 3150: Exam II 6 10/30/18

8 35. How many ml of O 2 would be generated at 402 C and 795 torr by the reaction of g Ba(ClO 4 ) 2? Ba(ClO 4 ) 2 (s) BaCl 2 (s) + 4O 2 (g) Molar Mass/g mol 1 (A) 1.81 ml Ba(ClO 4 ) (B) 205 ml (C) 344 ml (D) 819 ml (E) 1376 ml Check to see that you have entered 35 answers on your scan sheet. Make sure that you have bubbled everything correctly, including the ID number, Test Form, and Test Number. Proofread your work. You must return your scan sheet before leaving the room. MAKE SURE YOU HAVE ENTERED YOUR ANSWERS ON THIS PAPER so that you can check them against the key (hopefully posted online later today) and estimate your score. In addition, past tests make excellent study tools for the final exam. OUR CLASS WILL NOT MEET IN PERSON ON TUESDAY, NOVEMBER 6 (ELECTION DAY). If you did not yet vote and are eligible to do so, you must do so! Instead of in-person class, we will have a virtual class: Panopto recorded lecture, posted on Wordpress site: IF YOU ARE TAKING THE EXAM ANYWHERE OTHER THAN MGH 111 AT 5:45pm ON TUESDAY, OCTOBER 30, YOU MUST RETURN ALL PAGES TO THE PROCTOR. Sealed envelopes from the Testing Center or Access Office must be returned to the Chemistry Department office (KNCL 103) on Tuesday, October 30 in order to be graded! No one there? Slide under door. 3150: Exam II 7 10/30/18

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