WM

Question 1

physical properties of alcohols

Answer 1

polar due to polarised OH bond
hydrogen bonding present so higher BPs than corresponding alkanes
ability to mix with water due to hydrogen bonds

Question 2

effect of alcohol chain length on influence of OH group

Answer 2

as chain becomes longer, influence of OH group becomes less important
the larger the alcohol the more similar it is to its corresponding alkane
therefore solubility decreases as length increases

Question 3

primary alcohols

Answer 3

OH group attached to carbon which is bonded to only one other carbon
can be oxidised

Question 4

secondary alcohols

Answer 4

OH group attached to a carbon which is bonded to two other carbons
can be oxidised

Question 5

tertiary alcohols

Answer 5

OH group attached to a carbon which is bonded to three other carbons
cannot be oxidised due to no hydrogen atom on the carbon atom to which the OH group is attached

Question 6

oxidation of primary alcohols

Answer 6

aldehyde (no reflux and alcohol in excess)

aldehyde then carboxylic acid (reflux and oxidising agent in excess)

Question 7

oxidation of secondary alcohols

Answer 7

ketone and water formed (reflux with oxidising agent in excess)

Question 8

refluxing

Answer 8

safe method of heating flammable, volatile liquids

Question 9

dichromate ion as an oxidising agent

Answer 9

dichromate ion (orange)&raquo_space; chromate (III) ion (green)

Question 10

dehydration of alcohols

Answer 10

alcohols can lose a molecule of water to form an ALKENE

conditions: heated alumina (Al2O3) catalyst, or reflux with c. H2SO4

Question 11

nucleophilic substituion of alcohols

Answer 11

alcohols undergo nucelophilic substitution with halides in the presence of strong acid to produce haloalkanes

Question 12

esterification using alcohol and carboxylic acid

Answer 12

produces ester and water

very slow reaction unless a strong acid catalyst is used and is heated under reflux

Question 13

acid anhydride + alcohol&raquo_space;

Answer 13

ester + carboxylic acid

requires warming but produces high yield of ester

Question 14

phenol + acid anhydride&raquo_space;

Answer 14

ester + carboxylic acid

requires alkaline conditions

OH group in phenol is much less reactive so requires a more vigorous reagent to esterify it - acid anhydride

Question 15

purification of organic liquid products

Answer 15

during synthesis of organic liquids a crude product is usually produced
purified using separating funnel, drying agents or simple distillation

Question 16

test for phenol (and its derivatives)

Answer 16

go purple on addition of iron (III) chloride

Question 17

producing aspirin (2-ethanoyloxybenzoic acid) from salicylic acid

Answer 17

phenol group of salicylic acid reacts with acid anhydride

forms ester group

Question 18

producing oil of wintergreen (methyl 2-hydroxybenzoate) from salicylic acid

Answer 18

-COOH group on salicylic acid reacts with methanol (forms ester group)

Question 19

infrared spectroscopy

Answer 19

substances exposed to IR
molecules absorb IR of different frequencies
causes vibrational energy changes to occur within molecules

Question 20

bond deformation in infrared spectroscopy

Answer 20

diatomic molecules can only vibrate by stretching so they have just one vibrational infrared absorption

in more complex molecules, more bond deformations are possible (most involve more than two atoms)

Question 21

fingerprint region

Answer 21

region on infrared spectroscopy below 1500cm^-1
useful to compare spectra to find out if they are of the same compound
rarely used to identify functional groups

Question 22

mass spectrometry

Answer 22

used to find the atomic mass of elements and the relative abundances of isotopes in elements
can be used to identify more complex molecules

Question 23

molecular ion M+

Answer 23

heaviest ion in the mass spectra

corresponds to the original compound with one electron removed

Question 24

green chemistry

Answer 24

developing chemical products and processes that are as sustainable and environmentally friendly as possible

Question 25

key factors to consider for chemical processes:

Answer 25

cost, impact on environment, health and safety
changing reagents to improve atom economy may increase cost
changing reagents may raise new health and safety issues
reducing overall number of steps in process may reduce yield
lowered temperature may increase reaction time and hence cost