2311quiz3 2008 - Chemistry 2311, Fall 2008 Student Name _...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemistry 2311, Fall 2008 1 Student Name ______________________________ Last Name of TA _______________ Quiz #3A (75 pts) 1. Sublimation a. Why are some solids more easily purified by sublimation than others? That is, what are the properties of compounds that sublime readily at atmospheric or reduced pressure? +2 pts High solid vapor pressure OR when heated transform directly from solid to vapor without becoming a liquid. b. Under what circumstance would you choose sublimation technique as a means to purify a solid instead of recrystallization? + 3 pts Compound to purify is easily sublimed whereas impurities are not. Can sublime without decomposition, 2. Consider the Friedel-Crafts reaction below with three of the possible products: CH 3 3 Br FeBr 3 3 3 + + 3 3 + A BC 3 3 a. Which of the products given would you expect to be the MAJOR product? 2 pts A B C b. Give two reasons to support your answer above. 4 pts From most stable carbocation (which results from hydride shift), also the 1,2,4 product(s) will be favored over the 1,2,3. c. What is the purpose of the iron III bromide? 2 pts Since I did not ask for mechanism students can discuss hydride shift and show cation in box or give one of mechanisms below. . Br FeBr 3 H Hydride shift Br 3 +FeBr 4 O R H 4 d. Accurately draw three sigma complex intermediates involved in the formation of Compound C .
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/20/2010 for the course CHEM 2311 taught by Professor Wissinger during the Spring '10 term at University of Minnesota Duluth.

Page1 / 4

2311quiz3 2008 - Chemistry 2311, Fall 2008 Student Name _...

This preview shows document pages 1 - 2. Sign up to view the full document.

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