94088180_5155_SHALABI-SOPHIA_A.pdf

94088180_5155_SHALABI-SOPHIA_A.pdf - CHEM 1L0...

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Unformatted text preview: CHEM 1L0 LAB (40301-40390) (Illlfll Practical (Spring Qtr 2013) - LETTER SIZE 5155 (2109) Assigned Seattll: Wow Do not alter this ooversheet in ANY way. Substantial delays and additional fees may apply. 1. Clearly print your Last Name. First Name and the Date 2. Clearly print your Student ID number in the boxes provided. Use large. dark numbers. These numbers are captured automatically during the scanning process. 3dButabulergg each number of your Student lD completely. The bubbles are used only if your written ID number is n ca . 4. Write your Name and Student ID number in the upper right corner of all following pages of your exam. r (‘7 . Last Name. First Name: S‘V“ OOH-i V J \ "JD *1 \ Q Date: iii/fl STUDENT ID; For Access UCI student. ieaveflrsr colwrm blank then enter your 7-digir Student ID number. 8 O O 0 0 O 0 O O 8 9 0 O O 0 O O O O 9 0 O 0 O 0 0 O 7 0 0 0 --—-———---—-—------——-—----- (T his space for Instructor/'1' A use only) ------'--------------—-——--—- Graded by: Total Correct: 1 ( 1 Enthalpy and Entropy of a Borax Solution, version 1 No prompts for observations are given. Use the heck, of the page if a data and/or results table is needed. Provide answers to all questions in italics. Sample calculations are required. Staple plots (if any) to this page. 1) In a 250-mL beaker, create a supersaturated solution of borax in 50-75-mL of DI water. Heat with stirring to 65 °C. 2] Allow the solution to cool to approximately _§0_°C and .3?“ a slow m'mz3 0“ loci-Pro keep the temperature constant for about 10 minutes. U m 0&0 out — Collect 5 m1. of solution. 0 Te bomb 6% ‘1" C. 0 . . O f“ . M WHC_\ER\10lw;oM-F,m p 3) Fill a buret with a 0.500 M HCl solution. Titrate the ' (ms-mm 0. 15:1? 1"- ‘m solution collected in step 2. . "T‘MH o h ' {U -3° 4) Repeat procedure for a solution cooled to 55 °C as directed in step 2. a 5) Neutralize with sodium bicarbonate and pour solutions down the drain. (m )iemm (bggeom Determine AH (kj/mol) and detennine A /mol-quor the dissolution of borax. Show all calculations. ( R = 3.3145J/K-mol) C loo e. on Tt’z‘mwn -. fiss- s: +113: 33\-.5K he: «(on-1)": \‘ 3M6 \nwV-ers—c, -1 —' - 3— vatli): Omsolt. 92"“? 0 (9° «5’ cell./ ‘l'O-Tlsnomoos M TWVU>=CQ.§¢115:373.< our (“use . W‘W‘S‘Z l flyooswfl f“ ivtz 0 €2.15” _j ASZKbX‘LB 7 f \ A5: LO-owfi'*3(<zsoe\q\ [39 .-, m.¢'m§_urj5"‘hmo\ % {0 Au : (orwcu‘fszam _. . -. ' . J4 .‘ H La- AH - hp qugkm‘ 19’- r‘fifljuu 531.1 *3— 0 M. /_\ Htam\f‘0_\ ——'fi Score: a] 00 9’3 ‘ Titration Curves No prompts for observations are given. Use the by}; of the page if a data and/or results table is needed. Sample calculations are required. Staple plots (if any) to this page. ' ' it“! Learnt: 9“ °”* “>1 ‘3 new»; our-xii cote:- Q4 NaOH solution. Use a funnel to fill buret with 0.10 M NaOH solution. . Set up the buret, stirplate, and pH probe - LU in the manner used for titration. 5' 1‘6 5 . Place about 100 mL of DI water into a “M“ WNW- WOW}? - , m 250 mL beaker. Add 8.0 mL of 0.10 M W— 3 acetic acid (CH3C02H) and 3 drops of Dnomfigg w\of_ Mead L183 +0 9mg heno hthalein indicator. . 1.‘ p P 5 2m S-ccs. 9—“ ‘1‘" m3 "PU. \5 “1-10\/ 0 «RBIL. . Place a stir bar in the beaker and adjust ’ the stirplate to the appropriate speed. Acfifi C Rc‘td‘ Clear I calm“: 7’ 0 \ndk‘k’m-r: Chant buxofugE . Adjust the titrant drop rate to 2 drops per MO H Gem aa- Ldmf U3‘ second and begin oolieeting data. Snob“ \Ix-Kci 0.5: (\W 30039 (3 . Afier finishing the experiment, clean and : return all equipment to proper storage {riot iv )9 If W ()‘E "W 4) U . 0n the titration plot and indicate the equivalence point, the pH range of the bufi'ering region. the pH = pK, point, ' and the pH range of phenolphthalem . Neutralize all solutions with sodium bicarbonate and . ur down the drain. Score: W/SO Computational Study of SCN' The following molecular orbital images are of SCN'. Answer the following questions with WIN- 1. What do the acronyms HOMO and LUMO represent? Provide a definition for each too. g Humfi '. anegx ocwpved“ on oi-egwqr 6(qu\ (“QWS’V L ”H Lumo . . ' \JLUJL] .. (3 "UCLA. 9 MOWW\CAT Ofloi L0” 9* U” 9 ‘w h“ Hewett-Jew 2. Provide one orbital for each of the following: ‘_ a. a bonding for SC and 0N bonds: __M_ ‘1‘”) b. 0’" bonding for S-C and C-N bonds: —\fixmflfl-_P\K__ c. If“ bonding for S-C and C-N bonds: ling!) " 1 2S, d. a bonding for s-c and C-N bonds: Him ao- ; g e. a bonding for just S-C bond: , \J‘ 0 m 0 ' Lo X f. a bonding for just C-N bond: ‘R g m0 " I ’Z/ Score: /50 3. Describe the type of bonding in the HOMO. ems/M swam} x (7 4. List the 3 pairs of degenerate orbitals. (Degenerate orbitals have the same energy, just different orientations in three dimensional space.) Pair #1: Pair #2: Pair #3: ‘H‘DMO " l LAG-w: lam- How-0‘5 ' WMO’U Lumb+\ fl '-‘\c;y~r'~r'\O-—’l ' \- UmQ 5. Which molecular orbitals‘are the result of the combination of “5" atomic orbitals? S Q’TBM‘\ C. 0‘” h\*0\ MY»? a—Lfl’i S 3 n 6 “\O \. 6. Draw the two major resonance structures of SCN-. Show all lone pair electrons and indicate which atom the formal charge exists on in each resonance structure. {éflew‘j we. E‘Si>§‘9;y L 7. Do the M0 images favor one resonance structure over the other? Explain your anmer identifying M05 as evidence. , O “91 b\c_ m0 dkmcyrel ~35 8. A student creates an IR spectrum for an equilibrium geometry of SCN‘: Frequency (you) 1 1.4 6.1!:th i Inverse ‘Y'e-«erero‘qu VS- ,UHfi-QP y = 0.7751x + 0.0029 R2 = 1 Titration Curves of NaOH and Acetic Acid '9“ zvtu ' %¢§u\‘q\9hbe Qb\ h"? [o Sophia SJSGIZG1321236:19 Untitled ...
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  • Winter '13
  • Dr.KimberlyEdwards
  • pH, student ID number

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