Esters,fat and oils

What is an ester?

a molecule containing an ester link -COO-

What are esters used as? And why?

• flavourings and fragrances as many have pleasant, fruity smells

• solvents for non-polar compounds that do not dissolve in water

How are esters formed?

by a condensation reaction between an alcohol and a carboxylic acid

What is a condensation reaction

When two molecules are joined together with the elimination of a small molecule

What happens when an ester link is formed by the reaction between a hydroxyl group and a carboxyl group?

The small molecule eliminated is water

Esters can be ________ to produce an alcohol and a carboxylic acid.

Hydrolysed

What is a hydrolysis reaction?

When a molecule reacts with water to break down into smaller molecules

What are fats and oils?

concentrated source of energy

What are fats and oils essential for?

the transport and storage of fat-soluble vitamins in the body

How are edible fats and oils formed?

from the condensation of glycerol (propane-1,2,3-triol) and three carboxylic acid molecules

the carboxylic acids are known as ________ and are _________ or __________ straight-chain carboxylic acids

• fatty acids

• saturated

• unsaturated

bromine solution can be used to test fats and oils for the _____________.

degree of unsaturation

The higher the _________ the lower the __________?

• unsaturation levels

• melting point

How are bromine molecules added to fats and oils in an addition reaction?

There added across the carbon-carbon double bonds

Which has the lower melting points: edible oils or edible fats?

Edible oils

Double bonds in fatty acids prevent what? and what does this mean?

• Oil molecules from packing closely together

• The greater the number of double bonds present the weaker the van deer walls forces of attraction

the hydrolysis of triglycerides produces what?

one molecule of glycerol and three molecules of fatty acids which can be identical to or different from each other

Fatty acids always contain?

Even numbers of carbon atoms

What does the conversion of oils into hardened fat involve?

the partial removal of unsaturation by the addition of hydrogen