microdistillation

Question 1

what are the components of a micro distillation apparatus (5)?

Answer 1

-air condenser
-thermometer
-hickman head
-conical vial
-brick

Question 2

what is the purpose of the air condenser in a micro distillation apparatus?

Answer 2

cools hot vapors which allows them to condense back into their liquid state

Question 3

what is the purpose of the thermometer in a micro distillation apparatus?

Answer 3

measure the temperature of the reaction

Question 4

what is the purpose of the hickman head in a micro distillation apparatus?

Answer 4

serves as a receiving flask for distilling product

Question 5

what is the purpose of the conical vial in a micro distillation apparatus?

Answer 5

still pot for a microdistillation reaction

Question 6

what is the purpose of the brick in a micro distillation apparatus?

Answer 6

heats the sample in microdistillation and holds the thermometer

Question 7

what is dehydration?

Answer 7

process by which water is removed from a molecule, typically through the E1 elimination pathway

Question 8

describe the process of dehydration

Answer 8

-an alcohol is protonated by a strong acid, converting the poor leaving group (R-OH) to a much better leaving group (R-OH2+)
-H2O+ leaves to form a carbocation
-an adjacent hydrogen is removed, pushing electron density towards the carbocation and producing a new pi bond

Question 9

why did this reaction of an alcohol with sulfuric acid elicit an EI reaction compared to the reaction of an alcohol and hydrochloric acid eliciting an SN1 reaction?

Answer 9

-hydrochloric acid produces a nucleophilic chloride ion which can undergo SN1
-sulfuric acid is non-nucleophilic and cannot partake in the SN1 pathway

Question 10

how can we further favor the reaction of an alcohol and sulfuric acid towards the E1 pathway?

Answer 10

adding heat to the mixture because heat favors elimination

Question 11

why was microdistillation used to isolate the product in this weeks lab?

Answer 11

the volume of the sample was less than 5 mL

Question 12

how does an air condenser work?

Answer 12

utilizes ambient temperature to condense the hot vapor

Question 13

what does the bromine test look for?

Answer 13

the presence of pi bonds in a molecule

Question 14

what will happen in a bromine test if there are no pi bonds?

Answer 14

the brown color of the solution will persist

Question 15

what will happen in a bromine test if there are pi bonds?

Answer 15

the bromine will add across the bond, and the brown color of the solution will disappear, leaving a colorless solution

Question 16

draw a complete arrow pushing mechanism for the formation of cyclohexene from cyclohexanol using sulfuric acid

Answer 16

draw