Esters

Question 1

How are esters formed?

Answer 1

When you mix an alcohol and a carboxylic acid.

Question 2

What else is usually used in the formation of an ester?

Answer 2

An acid catalyst (e.g. concentrated sulfuric acid).

Question 3

What is the word equation for an ester formation?

Answer 3

alcohol + carboxylic acid → ester + water

Question 4

What do their names end in?

Answer 4

oate.

Question 5

What forms the first part of the esters name?

Answer 5

The alcohol.

Question 6

What forms the second part of the esters name?

Answer 6

The acid.

Question 7

What forms when methanol reacts with propanoic acid?

Answer 7

Methyl propanoate + water (is produced).

Question 8

What are esters used in?

Answer 8

perfumes.

Question 9

Why are esters ideal for perfumes?

Answer 9

• They have pleasant smells (usually sweet and fruity)

- They are volatile (meaning the evaporated molecules can be detected by smell receptors in your nose).

Question 10

Why does an esters volatility make it potentially dangerous?

Answer 10

As many esters are flammable/highly flammable.

Question 11

What happens when you try to mix an ester with water?

Answer 11

They don’t mix very well (they aren’t as soluble as alcohols or carboxylic acids).

Question 12

What do esters mix well with?

Answer 12

• Alcohols.

- Other organic solvents.

Question 13

What is the functional group of esters?

Answer 13

-COO.

Question 14

What else are esters used to make?

Answer 14

• Flavourings.
• Aromas.
• Ointments.
• Solvents.

Question 15

Why are esters used in flavourings and aromas?

Answer 15

E.g. there are some esters that smell or taste like rum, apple, orange, banana, grape, pineapple etc.

Question 16

What happens when esters are used in ointments?

Answer 16

E.g. they give deep heat its smell.

Question 17

What are esters used for solvents in?

Answer 17

• Paint.
• Ink.
• Glue.
• Nail varnish remover.

Question 18

What are the disadvantages of esters?

Answer 18

• Inhaling fumes from some esters irritates mucous membranes in the nose and mouth.
• Ester fumes are heavier than air and very flammable.
• Some esters are toxic, especially in large doses.
• Some people worry about the health problems associated with synthetic food additives (esters).

Question 19

What are the advantages of esters?

Answer 19

• They aren’t as volatile or as toxic as some other organic solvents.
• They don’t release nearly as many toxic fumes as some of the organic solvents.
• So they have replaced solvents such as toluene in many paints and varnishes.