Alcohols

Question 1

solubility of short chain alcohols (1-3C)

Answer 1

Because they have polar molecules due to the -OH group, they are soluble in H2O

Question 2

solubility of longer-chain alcohols

Answer 2

Not soluble in H2O as the long non-polar C chain makes the molecule non-polar

Question 3

melting and boiling point of alcohol

Answer 3

higher melting and boiling point than their corresponding alkanes due to stronger intermolecular forces between molecules

Question 4

how are c atoms numbered

Answer 4

to give the smallest number to the -OH group

Question 5

substitution reaction of alcohols

Answer 5

the -OH group is replaced by a halogen atom to form a haloalkane. regents such as PCl3 and PCl5 or SOCl2are often used to cause substitution by Cl

Question 6

oxidation reactions of primary alcohols

Answer 6

primary alcohols are oxidised to carboxylic acids using acidified dichromate (H+/Cr2O72-) or acidified permanganate (H+/MnO4-)

Question 7

elimination reactions of alchohols (dehydration)

Answer 7

when heated with concentrated sulfuric acid. the -OH group and an H atom on an adjacent C are removed (H2O) to form an alkene.

Question 8

dehydration reaction equation

Answer 8

alcohol arrow (conc H2SO4) alkene +H2O