14) Alcohols

Question 1

What is the functional group of an alcohol?

Answer 1

-OH

Question 2

Are alcohols polar or non-polar molecules?

Answer 2

polar

Question 3

Alcohols have a _ boiling point and _ volatility than alkanes. Why?

Answer 3

higher
lower
able to hydrogen bond, which requires more energy to overcome

Question 4

As chain length increases the effect of the -OH group _

Answer 4

decreases

Question 5

Alcohols are _ soluble in water than alkanes

Answer 5

more

Question 6

Give a word equation for the combustion of an alcohol

Answer 6

alcohol + oxygen -> carbon dioxide + water

Question 7

primary alcohol -> aldehyde + water

Answer 7

+ [O]
K2Cr2O7/H2SO4
distil
oxidation

Question 8

primary alcohol -> carboxylic acid + water

Answer 8

+ 2[O]
K2Cr2O7/H2SO4
reflux
oxidation

Question 9

secondary alcohol -> ketone + water

Answer 9

+ [O]
K2Cr2O7/H2SO4
reflux
oxidation

Question 10

What does [O] represent?

Answer 10

oxidising agent

Question 11

What will you see when performing the oxidation of alcohols with K2Cr2O7/H2SO4? Why?

Answer 11

colour change from orange to green

Cr2O7 2- -> Cr 3+

Question 12

Define dehydration

Answer 12

any reaction in which a water molecule is removed from the starting material; an example of an elimination reaction

Question 13

alcohol -> alkene + H2O

Answer 13

conc. H3PO4 and heat under reflux

dehydration

Question 14

alcohol -> haloalkane

Answer 14

+ hydrogen halide (made in situ with sulfuric acid and a sodium halide)
reflux
substitution