Exam 4 Test Form A - LAB SECTION 808 F0 2%":21; "...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: LAB SECTION 808 F0 2%":21; " A The University of Arizona Chem. 151 Spring 2008 Wayne E. Wesolowski, PhD / Andrew J. Grall, PhD EXAM No. 4 THE FOLLOWING MUST BE COMPLETELY FILLED-IN OR YOUR EXAM WILL NOT BE GRADED. NAME: PRINT (clearly) my signature below certifies that I have used a calculator for numerical calculations only and that I have not done anything unethical while taking this exam- NAME—- SIGN THERE IS A 3-POINT PENALTY FOR ILLEGIBLE NAMES or Scantron corrections DIRECTIONS oDO NOT OPEN THE EXAM UNTIL INSTRUCTED TO DO SO. OYOU MUST USE PENCILS ON THE SCANTRONS OON YOUR SCANTRON w WRITE AND BUBBLE IN YOUR STUDENT ID STARTING ON THE LEFT — FOR THE ‘8’ AT THE BEGINNING, BUBBLE IN A ZERO oON YOUR SCANTRON —— WRITE AND BUBBLE IN YOUR LAST AND FIRST NAMES SEPARATED BY A SPACE oFILL IN THE CORRESPONDING FORM LETTER GKEEP ALL PAPERS IN FRONT OF YOU, ON YOUR DESK AT ALL TIMES. OCROSS OUT ANY SCRAP WORK THAT YOU DO NOT WANT INCLUDED IN YOUR ANSWERS. OFOR MULTIPLE CHOICE QUESTIONS, BUBBLE IN THE LETTER ON YOUR SCANTRON OF THE CHOICE THAT BEST ANSWERS THE QUESTION. UNLESS NOTED THERE IS ONLY ONE CORRECT CHOICE. IF MORE THAN ONE CHOICE IS SELECTED THE QUESTION WILL BE MARKED WRONG. SELECT THE CLOSEST NUMERICAL ANSWERS IF YOUR CALCULATION IS SLIGHTLY DIFFERENT. oFOR QUESTIONS MARKED “FREE ANSWER” or PARTIAL CREDIT -- INCLUDE ALL YOUR CALCULATIONS. IF YOU GIVE ONLY THE CALCULATED ANSWER, IT WILL BE GRADED AS ZERO CREDIT. OPOINT ALLOCATION FOR EACH QUESTION 13 INDICATED. oGIVE ANSWERS FOR CALCULATIONS TO THE CORRECT NUMBER OF SIGNIFICANT FIGURES oWI-IEN YOU HAVE FINISHED PUT THE SCANTRON SHEET INSIDE THE BOOKLET BEFORE HANDING IT IN. OHOLI) YOUR PICTURE ID UP TO YOUR FACE WHEN TURNING IN AN EXAM OWHEN FINISHED, LAST NANIES BEGINNING A—K, TURN IN YOUR TESTS IN FRONT — LAST NANIES L-Z, TURN IN YOUR TESTS IN THE BACK DO NOT WRITE IN THIS BOX D D I] E] 18 19 Page 1 Multigle Choice —— Choose the BEST answer to each question and bubble it in on the scantron. Each problem is worth 3 points. 1. This chemical equation is NOT balanced 2 Al + {anal ~—>G?A1Cl3 4- gm When balanced the coefficient of H2 is: A)1 B) 2 C9} m4 2. For the reaction 2C0 + 02 --+ 2C02, if 3.0 moles of CO; were produced, how many moles of 02 must have reacted? a r .5 mol B) 2 mo! C) 3 mol 1)) 6 mol 3. For the reaction 2H2 + 02 "-9 2H20, if 4.9 moles of H; are mixed with 4.0 moles of 02, how many moles of H20 could he produced? A) 2 mol @4 mol C) 8 mol D) 16 mol 4. The following drawing contain a microscopic representation of a mixture of hydrogen H2(CO) and oxygen 02 (00) in a closed flask. 9. 00 If these substances react according to the following chemical equation 00 2H2 + 02 a 2H20 which of the following images best represents the content of the flask at the end of the reaction? Page 2 5. The following solutions were tested using a conductivity apparatus and the results are recorded. water Observation: liht u u u 5 Acid: compound(s) would be correctly labeled as a nonelectrolyte? 20 and C5H1205(aq) B) CH3COOH(aq) - ) H20,HI D) H] (aq),LiOH(aq) E) all five solutions 6. The oxidation number for nitrogen in each of the following items respectively is: N204 A1(N03)3 N02 4, +5, +4 B) 0,3, 0 C) +s,+1s, +4 1)) +6,+3,+6 7. Which of the following solutions will have the highest electrical conductivity? .eyo .5/6 .270 A; 0.10 M A1C13 B) 0.15 M CaBrz C) 0.25M NaBr 0.20M Mg(N03)2 E) 0.25 M KCIO4 . w »W 8. Balance the following equation. CuBrg + QNaBI—L; '9 H2 + 21mm + B2116 + Cu The SUM of all the coefficients (both reactants and products) is: (Be sure to count coefficients that are ONE) A) 4 B) 6 C) 12 @8 E) 18 _ 4'3” 1- (,1- 1+ @ *32+ 9. In the reactlon 2Mn04 + 10C] +1611 9 SC]; + ZMn + 81120 The reducing agent is: A) Mno4l' 11' C) 111+ D) (:12 E) Mn2+ Page 3 10. In the foiiowing reaction, identify the element in which the oxidation number goes up. 49' — 43 — 45 — avg — A804 (at!) + N02 (3‘!) “9 A502 (at!) + N03 (3(3) A) As B) 0 D) None of them go up 11. If you mix 10.0 moles of A4 with 50.0 moles of B2, which reactant is the limiting reagent? A4 + 6B2 ‘9 4AB3 A) A4 C) Neither is limiting 12. Below is a collection of C02 and H20 molecules resulting from the complete combustion of a hydrocarbon (CxI-Iy). What is the empirical formula of the hydrocarbon? A) CH B 4H16 C) C4H16 016 ) H4 13. Write out the NET IONIC EQUATION for the reaction: Ba(OH)2(aq) + 2H2804(aq) «9 BaSO4(s)+ 2H20(£) (hint write out the entire reaction with ions E2 '5‘? Q fifiv-Q’fféf‘“ => qffl: r $110 graded points) The SPECTATOR IONS are: A) Ba”, SO42" B) $042311“ C) H1", 0H ‘“ r_ . ere are no spectators Page 4 14. 0.. . [Ci—CH3 0-1-1: 0 O 0 9 E: a? ” "xx. Cs .OH QHa-wc 0H CHg-C \ + ‘\-. O * fl -- cagwc‘b xv!” 03H30+ 92F:in ngeOs ficefiizgfisdme Peseta salicylic acid Acetic acid Salicylic acid 19.39th In a lab, you began the above experiment with 5.0 g of salicylic acid and an excess of acetic anhydride. After the reaction was completed, you isolated 6.7 g of crude aspirin. After recrystallization to purify the product, you ended up with 2.8 g of ‘pure’ aspirin. What was the overall percent yield of your experiment? (fl-111503 = 138.1 glmol; (3911304 = 180.2 glmol) A) 97% B) 56% @394: D) 103% E) 75% 15. Which of the following statements is NOT true about the relationship between A and C? @ogcmoogA C) 3.0 x 1015 molecules c1213 3: 1015 molecules A D) 3 mol C 12 mol A 2A+B93C+2D A) 30 mo] C l 20 molA 16. How would you classify the foliowing reaction? Solid calcium metal reacts with water to form calcium hydroxide and hydrogen gas. B) combustion C) precipitation dox 17. How would you classify the following reaction? A) acid-base 2NaBr(aq) + Pb(N03)z(aq) —> PbBrz(s) + ZNaN03(aq) B) combustion @cipitafion D) redox A) acid—base Page 5 Free answer —— Answer the question completely — Show your work! Partial credit may be given. 18. (12 pts) If HX is a strong acid and HY is a weak acid and H22 is a soluble non- electrolyte Draw a picture of what each would look like at the molecular level in a solution with water. Draw at least four of each item do NOT include the water. HX dissoived in water HY dissolved in water H22 dissolved in water 19. Classify the following substances. Use the appropriate word (in each box) from the top of each column. (12 pt) Ionic or molecular Strong, weak or (before added to now-electrolyte (in HCOOH(£) I ' Kw 01' Page 6 20. Write balanced global (molecular) equations and net ionic equations for the following reactions in aqueous solution. If no reaction occurs, write NR. (Don’t forget phase labels) (12 pts) A Na2C03(aq) + Fe(N03)2(aq) ‘5' _,.I lobal molecular euation flagr-rg} +FéCfi§fg) IE9 fife“: Cog/3%)"? Qffisrfi net ionic e nation q) + Ca(0H)2(aq) 9 . global (molecular) e nation -- fee} t» m5?) 9 net ionic e - nation 21. Some automotive airbags work by the explosive reaction (13 pts) 2NaN3 --> 2Na + 3N2 If 95.5 g of NaN3 are used, what is the theoretical yield, in GRAMS, of N2? If 45.0 g of nitrogen gas is actually recovered, What was the percent yield? NaN3= 65.01 glmol MMN; =28.01 g/mol) Cf ' /%4“:~7%M ?" a $~ @373 1 97.332; Theoretical yield (g) Percent yield Page 7 Periodic Tabie 1 $40 E00 §70 00 31B §3A §4A §5A EBA §7A 18A 51.000 34.003 WWMWW W m .. E ._. gs gs E7 E0 E9 110 14 . . . 12 {Li 2313 18 EC in go EF éNe ' £10.01 £12.01 §14.01 E1000 £19.00 $20.10 . r. W. 2...... {11 1 §13 E14 515 316 :17 £10 éNa gMgi 5A: §Si §P 15 gel 1M 22.99 E2431 1 £0.90 €20.09 230.97 E3207 55.45 39.95 g i 7 E19 {20 121 §22 E23 §24 Q25 :20 :27 320 29 .30 §31 [32 E33 E34 E35 130 ' Cr EMn éFe ECO 30“ 'C 32 Ga iGe gAs éSe Br 1Kr 34 §K §Ca 15c 111 V i , . . i " I 139.10 140.00 44.90 347.00 i50.94 152.00 354.94 355.05 §50.93 250.09 03.55 J0me 09.72 72.01 174-92 @835 39190 $83.30 . l . z - - 7 0.8 149 {so :51 552 €53 $5 = 0 ( M. . puma“. WWW.._......W mmwfi m..." ‘___.___ i % u i 37 :30 i i40mmi711 342 £43 {314 E45 ‘40 4 g g E .119 de iIn Sn 250 gm :1 §Xe i , 3 a = 1 ’ § gs *Rb is: . a 3 a i , , . . 9 100.4 ]107.9 3112.4 3114.0 9110.7 5121.0 5127.0 E1209 1131.3 1 _.__..._~._...._____.25..__..__.=..__.-H_m . 155 E50 m.wwem.wzwm Wm... WWW , 57* 172 273 g74 $75 {76 “£77 {78 39 v §2r £100 1M0 in: 010 §Rh IPd 05.47.07.020091391.22392.91195.94}(90) 1101.1;1029 ‘ fi i l 79 30 ’01 ‘02 g0 Cs §Ba ELa in Ta 1W Re 105 EIr g 1 . E03 E84 Egmjas Au [Hg TE Pb gBi 5P0 At ;Rn . 132.9 $137.3 130.9 3170.5 5100.9 $103.9 100.2 190.2 092.2 3195.1 197.0 g200.0 1204.4 1207.2 §209.0 E(200) .(210) R222) ; . v mel‘ . E g , . y . E r , 1 E 307 [00 E09191 1104 3105 ’100 1107 E100 E109 {In} 111 3112 3 g7 Err §Ra EAc am 100 €59 i011 @115 5m 1 g g g 0223) g220.0 E2270 [(201) §(262) 1(253) (202) 5(205) ' (259) 4272) ;(277) i ...
View Full Document

This note was uploaded on 06/12/2008 for the course CHEM 151 taught by Professor Staff during the Spring '08 term at University of Arizona- Tucson.

Page1 / 8

Exam 4 Test Form A - LAB SECTION 808 F0 2%":21; "...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online