2010_Midterm_1

# 2010_Midterm_1 - Key for Midterm 1 CHEM 287, 13 October...

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page 1 of 8 printer 7211 Key for Midterm 1 CHEM 287, 13 October 2010 Total points possible = 45 before scaling. Grade calculated as 100*(points obtained +10)/55 The exam questions can be in a variety of orders. The key is presented in only one order, so you really need to focus on the question, not where it was in the exam. Please do not casually ask for your exam. There are over 200 exams and they are not in alphabetical order. If you can’t remember what question you missed, please go through the exam as though you were taking it again and see what you get for the various questions. This is a valuable learning exercise.

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page 2 of 8 printer 7211 Final SCORE was scaled as 100* (Score +10)/55
page 3 of 8 printer 7211 1. Which of the following is the correct representation for the number 4.18512 (+/- 0.31799%). (0.0031799*4.18512 = 0.013308 so uncertainty lies in 2 nd decimal place. Problem 3-10, answer is d note 4.185 rounds up to 4.19 a. 4.185 (+/- 0.013) b. 4.18 (+/- 0.01) c. 4.2 (+/- 0.01) d. 4.19 (+/- 0.01) answer e. 4.184 (+/- 0.013) f. 4.1851 (+/- 0.0131) 2. Use these answers for this problem, not the ones in the stapled version Find the absolute uncertainty and express the answer with a reasonable number of significant figures. (+/- = plus or minus). The product – 1.00 gives 0.395145, propagated error is +/- 0.02917 so uncertainty is in the 2 nd decimal. Number must be rounded to 0.40) [(68390 (+/- 80)) * (2.04(+/-0.04) *10 -5 )] - (1.00 +/- (0.01) a. 0.394156 (+/- 0.002971) b. 0.39415 (+/- 0.00297) c. 0.3951 (+/- 0.0029) d. 0.39515 (+/- 0.030) e. 0.395156 (+/- 0.02971) f. 0.39 (+/- 0.03) g. 0.40 (+/- 0.03) answer h. 0.41 (+/- 0.03) i. 0.395 (+/- 0.030)

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printer 7211 Questions 3-7: Choose which of following chromatography types is best represented by the figure above. Each of these is worth 1 point Answer 3. ion exchange c 4. adsorption a 5. affinity e 6. partition b 7. molecular exclusion d a. b. c.
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## This note was uploaded on 07/15/2011 for the course CHEM 287 taught by Professor Burns during the Fall '08 term at McGill.

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2010_Midterm_1 - Key for Midterm 1 CHEM 287, 13 October...

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