4 Organics 2 COPY

Question 1

Use the method below to name the ester made from ethanol and methanoic acid

Answer 1

ethyl methanoate

Question 2

Esters are very volatile (evaporate easily) and smell or taste sweet. What are esters used for?

Answer 2

fragrances in perfumes OR flavourings in food

Question 3

Name the homologous series

Answer 3

carboxylic acid

Question 4

How do you know that the formation of ethanoic acid from ethanol is oxidation?

Answer 4

ethanol has gained oxygen

Question 5

What type of reaction is shown below?

Answer 5

Complete combustion of ethanol

It is an exothermic reaction

Question 6

What are products for the reaction between ethanoic acid and sodium carbonate

Answer 6

metal carbonate + acid –> salt + water + carbon dioxide

Question 7

Name the ester

Answer 7

ethyl hexanoate

Question 8

Name the ester

Answer 8

ethyl butanoate

Question 9

What conditions are needed to oxidise ethanol

Answer 9

potassium dichromate VI - oxidising agent

conc. sulfuric acid - catalyst

heat

NOT|E: mixture will turn from yellow to green

Question 10

Describe how to safely make and smell an ester from ethanoic acid and propanol

Answer 10

1. Place six drops of concentrated sulfuric acid into a test tube
2. Add 1 cm³ of ethanoic acid
3. Add 1 cm³ of propanol
4. Swirl gently and add the test tube to a hot water bath
5. Leave for 5 minutes
6. Pour the mixture into a beaker of sodium carbonate to neutralise the concentrated acid
7. Carefully waft the fumes towards your nose to identify the sweet ester smell

Question 11

Name the ester

Answer 11

ethyl propanoate

Question 12

Name the functional groups which are identified on this molecule

Answer 12

red = carboxylic acid (COOH)

green = ester (RCOOR’)

Question 13

Name the two homologous series

Answer 13

alkane

AND

alcohol

Question 14

What is the function of potassium dichromate (VI) in the oxidation of alcohols

Answer 14

potassium dichromate (VI) is the oxidising agent

It supplies oxygen [O]

It, itself is reduced

Question 15

Name the products made from:

sodium carbonate and ethanoic acid

AND potassium metal added to propanoic acid

Answer 15

sodium hydroxide + ethanoic acid –> sodium ethanoate + water + carbon dioxide

potassium + propanoic acid –> potassium propanoate + hydrogen

Question 16

Identify the homologous series

Answer 16

ester

Question 17

Why is ethanoic acid a weak acid?

Answer 17

ethanoic acid does not fully dissociate into H+ ions

Only 4 in 100 molecules dissociate - less H+ ions = weaker acid

Question 18

Name the homologous series depicted below

Answer 18

Carboxylic acid

Question 19

What type of reaction is esterfication?

Answer 19

Condensation reaction

(water condenses out) leaving a carbon-oxygen bond between the carboxylic acid and alcohol

Question 20

Use the method below to name the ester made from propan-1-ol and butanoic acid

Answer 20

propyl butanoate

Question 21

Use the method below to name the ester made from

butan-1-ol and propanoic acid

Answer 21

butyl propanoate

Question 22

What are the observations and products formed when magnesium is added to ethanoic acid

Answer 22

slight fizzing (as ethanoic acid is a weak acid)

magnesium ethanoate + hydrogen

Test for hydrogen- flaming splint goes squeaky pop

Question 23

Name the identified functional groups on this molecule

Answer 23

OH = alcohol

COOH = carboxylic acid

Question 24

What would happen if fermentation of glucose was carried out in the presence of oxygen or aerobically?

Answer 24

ethanol would oxidise to ethanoic acid

Question 25

Name this salt

Answer 25

sodium ethanoate