Alcohols & Carboxylic Acids

Question 1

general formula & functional grp alcohol

Answer 1

CnH2n+1OH, Hydroxyl -OH

Question 2

physical properties alcohol (1)

Answer 2

volatile (easily evaporated) liquids at rtp

Question 3

chemical properties alcohol (2)

Answer 3

combustion, oxidation (w/ bacteria & o2, acidified KMnO4)
- hydroxyl grp responsible for rxns

Question 4

oxidation w/ acidified KMnO4 (2)

Answer 4

1. reagents: acidified potassium manganate (vii) soln, KMnO4
2. conditions: heat

Question 5

oxidation w/ o2 & bacteria in air (4)

Answer 5

1. reagents: o2
2. conditions: presence of bacteria
   - alcoholic drinks turn sour after being exposed to air & bacteria bc formation of ethanoic acid
   - not suitable for large scale production of ethanoic acid

Question 6

test alcohol

Answer 6

add KMnO4
alcohol: turn colourless
acid: no change, remain purple

Question 7

production alcohol (2)

Answer 7

1. fermentation of glucose to produce ethanol
2. addition of steam to alkenes

Question 8

fermentation of glucose to produce ethanol (3)

Answer 8

1. reagents: C6H12O6
2. conditions: 37 C, absence O2, yeast, h2o
3. eqn: c6h12o6 -> 2 c2h5oh + 2 co2

Question 9

reasons for fermentation conditions (2)

Answer 9

1. absence o2: anaerobic respiration
   - if o2 present, aerobic respiration occurs -> co2 + h2o, ethanol may oxidise to carboxylic acid
2. temp 37 C: yeast works best at this temp
   - above this temp, enzymes denature

Question 10

general formula & functional grp carboxylic acid

Answer 10

CnH2n+1COOH, Carboxyl -COOH

Question 11

physical properties carboxylic acid (4)

Answer 11

weak acids
1. sour
2. conduct electricity dissolved in h2o
3, turn damp blue litmus paper red
4. VERY SOLUBLE in h2o

Question 12

chemical properties carboxylic acid (2)

Answer 12

combustion, common rxn as weak acid (+ reactive metal/carbonate/base)

Question 13

define condensation

Answer 13

rxn in which two/more reactants form larger molecule W/ LOSS of small molecule like h2o, hydrogen halide, nh3

Question 14

acidic hydrolysis of esters (3)

Answer 14

1. reagents: dilute acid like HCl
2. conditions: heat
3. def: a rxn in which a molecule is broken down into SMALLER molecules by addition of h2o

Question 15

esterification (4)

Answer 15

1. reagents:
2. conditions:
3. purpose h2so4:
4. naming esters: