4.2

Question 1

alchohol general formulae

Answer 1

CnH2n+1OH

Question 2

boiling point of alcohols

Answer 2

increases as chain length increases, is higher than that of alkenes due to hydrogen bonding

Question 3

impact of branching on boiling point

Answer 3

branching reduces boiling point due to reduced surface contact

Question 4

solubility in water of alcohols vs alkenes

Answer 4

alkenes insoluble in water, alcohols are soluble in water because they are polar and from hydrogen bonds

Question 5

primary alcohol

Answer 5

OH group is attached to a carbon that is attached to one other carbon / has 2 hydrogens attached to it

Question 6

secondary alcohol

Answer 6

OH group is attaches to a carbon that is attached to 2 other carbons / has one hydrogen attached to it

Question 7

tertiary alcohol

Answer 7

OH group is attached to a carbon that is attached to 3 other carbons / has no hydrogens attached

Question 8

what is used to oxidise alcohols

Answer 8

potassium dichromate shown as K2Cr2O7 / H2SO4 or Cr2O7 ^-2 / H^+

Question 9

what does potassium dichromate look like

Answer 9

orange solution that turns green when reduced

Question 10

oxidation of tertiary alcohols

Answer 10

not oxidised under these contidions, for it to oxidise the C the OH is attached to must have a H

Question 11

oxidation of secondary alcohols

Answer 11

oxidise to form keytones

Question 12

ketones

Answer 12

functional group C=O not at the end of the chain, names end in -one

Question 13

oxidation of primary alcohols

Answer 13

oxidise once to from aldehydes under distillation and can oxidise further to form carboxylic acids under reflux

Question 14

aldehydes

Answer 14

C=OH functional group at the end of the chain end in -anal

Question 15

alcohols into alkenes and back

Answer 15

H2O can be removed from alcohols in the presence of heat and a H3PO catalyst. The OH is removed from one carbon and the H from the adjacent carbon forming a c=c bond

Question 16

alcohols into haloalkanes

Answer 16

the OH group can be substituted for a halide ion in the presence of a halide salt solution and acid catalyst

Question 17

nucleophylic substitution

Answer 17

the halo-carbon bond becomes polar leaving it open to attack by nucleophiles. The nucleophile uses its Lone pair to provide the electrons for a new bond displacing the halogen

Question 18

nucleophile

Answer 18

electron pair donor - will probably have a lone pair

Question 19

problems with CFCs / haloalkanes

Answer 19

in the atmosphere the halogen radical will react with ozone to from a halogen oxygen radical that reacts further with ozone. overall reaction O3 + O -> 2 O2

Question 20

infrared spectroscopy

Answer 20

works by firing IR radiation at a compound. Different bonds absorb different amounts and frequencies of IR radiation. Looking at the absorption spectra allows you to identify the bonds in compounds

Question 21

stages of spectroscopy

Answer 21

vaporisation, ionisation, acceleration, deflection, detection