Esters, Fats and Oils

Question 1

Ethanol+propanoic acid forms what ester?

Answer 1

Ethyl Propanoate

Question 2

Ethyl butanoate + water forms what

Answer 2

Butanoic acid and Ethanol

Question 3

Ethyl butanoate + Sodium hydroxide forms what

Answer 3

Ethanol and Sodium butanoate

Question 4

State some uses of Esters

Answer 4

Many esters are used as flavourings and in perfumes

Question 5

What is another name for glycerol

Answer 5

Propane-1,2,3-triol

Question 6

What are long chain carboxylic acids called

Answer 6

Fatty acids

Question 7

How are fats and oils formed

Answer 7

They are formed from the combination of 3 moles of fatty acids : 1 mole of glycerol

Question 8

What is the ratio of fatty acid to glycerol in their formation

Answer 8

3:1

Question 9

What are fats and oil at room temp.

Answer 9

Fats are solid while oils are liquids

Question 10

How are emulsifiers made from edible oils

Answer 10

By reacting edible oils with glycerol

Question 11

Explain fully how emulsifiers prevent non-polar and polar liquids from
separating into layers.

Answer 11

The emulsifier has two parts that are Hydrophobic and Hydrophilic

The hydrophobic part dissolves in nonpolar liquid while the hydrophilic part dissolves in polar liquids

Question 12

What is the function of an emulsifier

Answer 12

They prevent the non polar and polar liquids separating (into layers)

Question 13

Explain why antioxidants are added to foods

Answer 13

To prevent unwanted oxidation or to stop foods from acquiring a rancid flavour

Question 14

How are soaps made

Answer 14

They are made from the Hydrolysis of fats and oils

Question 15

State cleansing action of soaps

Answer 15

The soap molecule separates into soap ion and sodium ion when in water
The hydrophilic heads face out into the water
The hydrophobic tails dissolves in a droplet of grease
The dirt or greece is held inside a ball and suspended inside the water

Question 16

How are esters formed

Answer 16

by reacting an alcohol with a carboxylic acid

Question 17

What are miscells

Answer 17

They are greece droplets

Question 18

What is an emulsion

Answer 18

An emulsion contains small droplets of one liquid, dispersed in another liquid.

Question 19

Describe an emulsifier

Answer 19

It has two ends which are:
A hydrophilic (water loving) Head
A hydrophobic (water hating) Tail

Question 20

What do hydrophilic forms

Answer 20

They form bonds with water but not with oils

Question 21

What do hydrophobic forms

Answer 21

They form bonds with oils but not with water

Question 22

Why does palm oil have a higher melting point than olive oil

Answer 22

This is because palm oil has significantly more saturated fatty acid content.

Question 23

Name two products formed when fats and oils react with sodium hydroxide

Answer 23

A soap and glycerol

Question 24

What reaction can produce salts from fats and oils

Answer 24

Alkaline Hydrolysis

Question 25

Glycerol can be obtained from fats by which process?

Answer 25

Hydrolysis

Question 26

Describe the parts of a soap molecule

Answer 26

The tail of the molecule is nonpolar and hydrophobic while the head is ionic and hydrophilic

Question 27

Why is concentrated sulphuric acid used in esters reactions?

Answer 27

It acts as a catalyst for the reaction

Question 28

Esters have relatively ___ boiling points allowing them to evaporate easily

Answer 28

LOW

Question 29

Fats are formed from ——— fatty acids

Answer 29

Saturated

Question 30

What happens when a fat is heated

Answer 30

Intermolecular forces are broken and the fat melts

Question 31

Why does coconut oil have a higher melting point than olive oil.

Answer 31

London dispersion forces between coconut oil are stronger than in olive oil