Oils & Fats

Question 1

WHAT IS MEANT BY OILS AND FATS?

Answer 1

Esters produced through the reaction between fatty acids and glycerol

Question 2

WHAT DOES THE CHARACTERISTICS OF OILS OR FATS RELY ON?

Answer 2

Rely on the types of fatty acids involved in the esterification reactions with glycerol

Question 3

WHAT ARE THE DIFFERENCES BETWEEN OILS AND FATS?

Answer 3

OILS
Source:Plants
Physical state at rtp: Liquid
Melting point: Low 
Content of fatty acids: High % of unsaturated  fatty acids
Example:Palm Oil

FATS
Source: Animals
Physical state at rtp: Solid
Melting Point:High
Content of fatty acids: High % of saturated fatty acids
Example:Butter

Question 4

WHY OILS EXIST AS LIQUID AT ROOM TEMPERATURE?

Answer 4

Because it have low melting points

Question 5

DEFINE ESTERIFICATION REACTION.

Answer 5

Reaction between Glycerol and fatty acids to produce Fat.

Question 6

WHAT IS THE HOMOLOGOUS SERIES FOR FATTY ACIDS AND GLYCEROL?

Answer 6

Carboxylic Acids

Question 7

DESCRIBE SATURATED FATS AND GIVE SOME EXAMPLE OF SATURATED FATTY ACIDS.

Answer 7

-Contains saturated fatty acids
-Only have single covalent bond in the carbon chain (C-C)
EXAMPLES:
•Palmitic acid
•Lauric acid
•Stearic Acid

Question 8

DESCRIBE UNSATURATED FATS AND GIVE SOME EXAMPLE OF UNSATURATED FATTY ACIDS.

Answer 8

• Contain unsaturated fatty acids
• Have at least one double bond in the carbon chain (C=C)

EXAMPLE:
•Oleic acid
•Linoleic acid
•Linolenic acid

Question 9

Unsaturated fats contain unsaturated fatty acids that have at least one double bond in the carbon chain(C=C).What effect does it contribute to?

Answer 9

-Presence of double bonds causes unsaturated fats to have low melting points and exist as liquids

Question 10

HOW CAN UNSATURATED FATS BE CONVERTED INTO SATURATED FATS?

Answer 10

Through Hydrogenation reaction

Question 11

HOW HYDROGENATION OCCUR?

Answer 11

• Hydrogen gas is passed into hot oil
• Nickel is used as catalyst to speed up the process
• The double bond in the carbon chain is ‘opened’
• Hydrogen atoms are added to the carbon chain.
• Addition of hydrogen atoms to the carbon chain increases the molar mass that leads to increase in melting point and boiling point.

Question 12

EXPLAIN WHY MARGARINE EXISTS IN A SOLID FORM AT ROOM TEMPERATURE, EVEN THOUGH IT IS PRODUCED FROM OIL.

Answer 12

• Oils contain high percentage of unsaturated fatty acids
• The unsaturated fats undergo hydrogenation
• As Hydrogen atoms is added in the process, its molar mass increases
• As the molar mass increases, the melting point and boiling point also increase and margarine exists in a solid form

Question 13

BETWEEN OILS AND FATS, WHICH ONE CAN LAST LONGER AND CAN STAND FROM TURNING RANCID? WHY?

Answer 13

• Fats can last longer compare to oil
• This is because unsaturated fats are more susceptible to oxidation (likely to oxidise) compared to saturated fats
• Rancid is a result of oxidation

Question 14

WHAT ARE THE USES OF OILS AND FATS IN LIFE?

Answer 14

• To produce biofuels to be used by vehicles with diesel engines.
• Supply energy and helps the body to absorb important vitamins (A,D,E, and K)
• Main ingredients for soap making and personal care items
• Used to manufacture feeds for cattle to fulfil their nutritional needs

Question 15

WHAT ARE THE EFFECTS OF EXCESSIVE INTAKE OF OILS AND FATS IN OUR DIET?

Answer 15

• Heart disease

- Obesity