6.4

Question 1

what is the general formula for alcohols

Answer 1

CnH2n+1OH

Question 2

describe chlorination

Answer 2

use phosphorous chloride
vigorous at room temperature

Question 3

describe chlorination of tertiary alcohols

Answer 3

mix with concentrated HCl at room temperature

Question 4

describe bromination

Answer 4

use potassium bromide and 50% concentrated sulfuric acid

Question 5

describe iodination

Answer 5

use red phosphorus and iodine
heat under reflux

Question 6

describe dehydration to alkenes

Answer 6

heating the alcohol with phosphoric acid

Question 7

define ketones

Answer 7

a homologous series of organic compounds formed by oxidation of secondary alcohol

Question 8

define aldehyde

Answer 8

homologous series of organic compounds formed by the partial oxidation of primary alcohols

Question 9

is a ketone or an aldehyde more easily oxidized

Answer 9

aldehyde

Question 10

what is an aldehyde oxidized to

Answer 10

carboxylic acid

Question 11

define carboxylic acid

Answer 11

homologous series of organic compounds formed by the complete oxidation of primary alcohols

Question 12

what do primary and secondary alcohols form when they are oxidized

Answer 12

secondary alcohol -> ketone
primary alcohol -> aldehyde -> carboxylic acid

Question 13

what are the reagents for oxidation of alcohols and how are they represented in an equation

Answer 13

potassium dichromate (VI)
dilute sulfuric acid
[O]
colour change - orange -> green

Question 14

what is heating under reflux

Answer 14

heating a reaction mixture with a condenser fitted vertically

Question 15

what is distillation with addition

Answer 15

heating a reaction mixture but adding another liquid and distilling off the product as it forms

Question 16

what could be contaminating organic compounds

Answer 16

unreacted starting materials
other organic compounds
inorganic reagents
inorganic products
water

Question 17

what techniques can be used to purify an organic mixture

Answer 17

simple distillation
fractional distillation
solvent extraction
drying

Question 18

what are the issues with doing practical’s with organic substances

Answer 18

flammable
toxic
increased risk of leaks and contamination

Question 19

define simple distillation

Answer 19

used to separate liquids with very different boiling temperatures

Question 20

summarize simple distillation

Answer 20

heat in flask with condenser
lowest bp evaporates first and is passed to the condenser
thermometer monitors temperature
if temp remains steady a compound is being distilled

Question 21

define fractional distillation

Answer 21

used to separate liquids with similar boiling temperatures

Question 22

summarize fractional distillation

Answer 22

same apparatus as simple distillation with a fractionating column filled with glass beads so the vapor can condense and evaporate repeatedly which provides better separation

Question 23

define solvent extraction

Answer 23

used to separate a liquid from a mixture by causing it to move from the mixture to the solvent

Question 24

what does immiscible mean

Answer 24

doesn’t mix

Question 25

summarize solvent extraction

Answer 25

place reaction mixture in a separating funnel
stopper and gently shake
allow contents to settle
open tap and allow the lower layer to drain

Question 26

state some good drying agents and why they are effective

Answer 26

anhydrogenous salts (calcium sulfate, magnesium sulfate, calcium chloride)
doesn’t react with the organic compound
adsorbs the water as water of crystallization forming a hydrated salt

Question 27

summarize drying

Answer 27

drying agent added, swirled and left for a period of time
drying agent goes from powdery to crystalline and when the organic liquid has been dried more drying agent can be added and it will stay a powder
drying agent is removed by filtration on decantation

Question 28

how do impurities effect boiling points

Answer 28

more impurities the higher the bp