{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

practice_exam_ii_s04_key

practice_exam_ii_s04_key - Exam II Page 2 of 11 Part I...

Info iconThis preview shows pages 1–10. 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 Document Right 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 Document Right 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 Document Right 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 Document Right Arrow Icon
Background image of page 8
Background image of page 9

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

View Full Document Right Arrow Icon
Background image of page 10
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Exam II Page 2 of 11 Part I: Multiple Choice, Concepts Circle the correct answer and enter your response on the cover - No partial credit 1. ‘ In the reaction C4H9€| (aq) + H20 (I) 9 C4H90H (aq) + HCI (aq) the concentration of C4H9C| changes from 0.0562 M to 0.0431 M in 85 sec. What is the average rate of decomposition over this interval? . ,3 , .1.54 x10'4 M/5 \n .2 ” ”ML—fl 2 ’- 80 ‘Qlfi ” 0‘ ngl B. 1.54 x 10‘4 moles l) 30 (fig «b > c. 1.54 x 10-4 moles/s D. 0.0154M 5‘: \VQACNQHA‘ MlS E. none of the above 2. If increasing the concentration of A in a chemical reaction causes no increase in the rate of the reaction, then we may say: $3 A. A is not involved in the reaction V 2 "QQERE B the reaction rate is zero order in A @the reaction rate is zero order in [A] 7 ’h D. the reaction rate is first order in [A] E. none of the above 3. The reaction A + B 9 C + D is second order in A and zero order in B. The value of k is 0.012 M‘1 min'l. What is the rate of this reaction when [A] = 0.125 M and [B] = 0.435 M? . -4 ' -1 - “2.. - 95’ l; :.:>1<010'gAMmr:in'1 V“ ’2 —QQ [9‘1 [.931 C. 1.3 M min"1 7:. ,% LAEL ‘ 1.9 x10'4 M min'1 : {O ‘ QO:\L©. \ZC L‘ . none of the above ‘ 1‘” l (5Xl6m‘l M/wa 4. The reaction has the rate law Rate = k[A][B]2. Which will cause the rate to increase the most? A. doubling [A] ZR. B. lowering temperature \Lfl @tripling [B] ELL D. quadrupling [A] 4-R E. none of the above \ZAVHKAL (\L. I b\4\\\v C) (AL) \ Exam II Page 3 of 11 5. The raTe consTanT aT 160 °C for The firsT order decomposiTion of ore is 0.032/min. The half—life of The reacTion is: A. 62.5 sec CE). 1300 sec ”EL/z ?‘ C. 5000 sec D. 111 sec E. none of The above 6. Molecules which are nonsuperimposable mirror images of each oTher are called: A. achiralomers (ED enanTiomer‘s C. diasTereomers D. cis/Transomers E. none of The above 7. The model for bonding in complex ions ThaT considers The meTal-ion/ligand bonding as an elecTrosTaTic aTTracTion of The meTal ion nucleus for ligand elecTrons, wiTh repulsions beTween ligand elecTrons and The elecTrons of The cenTr'al meTal ion, is called The: A. oTomic orbiTal Theory @crys’ral field Theory C. VSEPR Theory D. molecular orbiTal Theory E. none of The above 8. [CuCl4]2‘ absorbs lighT inThe blue parT of The visible specTrum, Thereby appearing To have The color: A. blue E. none of The above Exam II . Page 4 of 11 Part II: Short Answer Fill in the blank 9. (4 points) Draw the Lewis structures for the following molecules in the box provided. Identify the geometric and electronic shapes with respect to the underlined atoms. Clay“ Umkkdmvg :2 SCQJW ‘f 3% Geome fShape: 3C CSUUL, QQQ/qujx D Electrcgcjihape‘ Qdmemdmg 10. (12 points) Data for the reaction A + B 9 C are given below. Find the rate constant (k), the exponents (m and n) for this system where rate = k [A]"‘ [3]", and which plot will give a straight line. Don't forget the units! Experiment |A| M |B| M Initial rate M/s 1 0.030 0.060 2.5x10-5 2 ’ 0.030 0.020 2.5x10—5 3 0.060 0.060 10.0x10-5 r3- _ Q‘QBOv'M £210.32: [‘1 0.030 * LCMO" * a“ 3 AV / «A: Z r m 0.050 “A “1.52am 5 7 [Cu/F c) 010 "' Zr? “(gs “ ._ 3 ': \J V\ * O Exam II Page 7 of 11 Part III: Long Answer Please show all work - Partial credit 15. (16 points) An unknown transition metal complex, [MLX]3’, is isolated in a flask. The transition metal M and ligand L are unknown. The ligand is found to be neutral, and the metal is in the manganese group. The complex is low spin, slightly paramagnetic, and the solution color is between\@: anid yellow, ' Tb§ A. (2 points) What is the eleccfgonic configuration of the metal M? A4 B. (8 points) Using the information given above, determine the shape of the complex (octahedral, tetrahedral, or square planar). i "t “at.“ a \3. b ,_, C” G: 4H; ‘t— -i—~ Art it y 3d: 4dr} 3%— Lo \e:\’ 1 QFT A : Amzwo‘ggGD W+<+sogmgapgoeul D. (4 points) If a weaker field ligand was coordinated to M instead of L, would you expect the solution color to be yellow or orange? my aim *i ® ED 6%: ,,#,, j Exam II Page 8 of 11 16. (24 points) The following rate law has been determined for the decomposition of ozone in the reaction 2 03 (9) a 3 Oz (9) Rate of decomposition of 03 - k [03]2 2/fi IHMS LL We GAIWSLUQK' ,/ “k0 . QMJV E . The following mechanism has been proposed: Step 1 03 <$ 02 + 0 (fast) Step 2 O + 03 9 02 + 02 (SIOW) Derive the rate law and confirm that it matches the observed rate law. A. (6 points) Write the forward (r1) and reverse (rl') rates for Step 1 and the forward (r2) rate for Step 2 in the space provided below. Exam II Page 9 of 11 # 16 Continued... C. (6 points) Use the pseudo steady—state hypothesis (steady-state approximation) to find an expression for the intermediate. V QWCLI\ 7: ”(\:Q°LRX~Q USN r @ / y_‘_ r @ “l2 Log-1‘7 filo [BEIGE JVQQ EKG} is? All “A @ W ww/If— D. (3 points) Write an expression for the rate of decomposition of 03. Hint: Step 2 is the slow step. (dug. “:— C1. '33 “klllgllagl E. (7 points) Substitute the expression for the intermediate (part C) into the expression for the rate of decomposition of 03. Hint: Step 2 is the slow step— you will use the fact that r2 << H to simplify your overall expression \.~l~Je_ gas We, 1‘0.th dewgfi-‘M K V << n £03 3W3 SIMQ V SS Im Exam II Page 10 of 11 Spec’rrochemical Series: CN‘>CO>flOg3en>NH3>SCN>HzO>QNO'>0x2“>OH'>F‘>§CN'>CI'>Br'>I‘ Consfan'l's: R = 8.3145 J / mol K F = 96,485 (2/ mol 8' R = 0.03206 L am / mol K c = 2.9979 x10a m / s h = 6.626 x10‘34 J" 5 Equations: A = h c /A (first order) (zero order) (second order) In [A]? = In [AL - kt [AL = [61° - :0 [A];1 = [Ala-1+ m 1’1/2 = (In 2) / k 1’1/2 = [AL/2k 1'1/2 = 1 / (HAL) — Ba 6 E _ E_a L_L k = A3 RT k R T T’ 560 ' / Name E Student ID Number Lab TA Name and Time Dr. Bryan Enderle Spring 2004 CHEMISTRY 2C Exam II Instructions: CLOSED BOOK EXAM! No books, notes, or additional scrap paper are permitted. All information required is contained on the exam. Place all work in the space provided. Thank you for reading the instructions. If you require additional space, use the back of the exam. (1) Read each question carefully. (2) There is no partial credit for the problems in Part I and Part II. (3) The last page contains a periodic table and some useful information. You may remove this for easy access. (4) Graded exams will be returned in the discussion sections next week. (5) If you finish early, RECHECK YOUR ANSWERS! U.C. Davis is an Honor Institution p ible p: i l b s 0-7 -m- Total Score (100) EXQMLL Kh‘f ESVKle'oKOOCl- Exam II Page 5 of 11 11. (16 points) Matching: in the column marked “Answer," fill in the statement number that / best describes the element. Statement — Which element is it? 1. This element is found in biomolecules, explosives, air, fertilizer, and rocket fuel. with heavy noble gases. table. ion exchange. 5. This metal chloride, like aluminum chloride, forms a structure in which the chlorine atoms lie in two perpendicular planes. 6. This fourth row metal can be identified by a flame test. 7. This metalloid is found in the 4Th row of the periodic table. 8. This metal, found in salt water, is soft enough to cut with a knife. 4..i\.r\\vx_;_;, r‘b \ L‘KIIVD LLLJ'T Exam II . Page 6 of 11 12. (4 points) Reactions: fill in the blank with the appropriate molecule. Ca+H2-9 m 2A|+3/ZOE-> m 13. (3 points) Indicate if the following molecules have optical iSOmers. Please answer “yes" or ll If no. m Optical Isomers (yes or no)? 14. (5 points) Draw the five d orbitals below. Please label each orbital and include the axis. ® 3 éx—tq’ Ql‘ $1 ©®® ...
View Full Document

{[ snackBarMessage ]}