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What is a difference between vulcunised rubber and unvulcunised rubber ?

• Vulcunised rubber are more elasticity than unvulcunised rubber

• Vulcunised rubber are less resistant to high heat while unvulcunised rubber are resistant to high heat

• Vulcunised rubber are easier to be oxidised while unvulcunised rubber more resistant towards oxidation

• The hardness of vulcunised rubber are soft while the hardness of unvulcunised rubber are hard

How does the process of vulcanization affect the properties of rubber?

• It makes the rubber softer and less durable

• It increases the strength and elasticity of rubber

• It decreases the resistance to chemicals in rubber

• It has no impact on the properties of rubber

What happen to the double bond during vulcanization process?

• The single bond between carbons found in rubber molecules will react with sulphur cross-links .

• The double bond between carbons found in rubber molecules will react with sulphur cross-links .

• The triple bond between carbons found in rubber molecules will react with sulphur cross-links .

• The double bond between carbons found in rubber molecules will react with carbon cross-links .

What is the characteristic of unvulcanisation rubber?

• Less elastic

• Very elastic

• High elasticity

• Low elasticity

How to tell if rubber is vulcanized?

• It's less dense and heavier, and when exposed to mechanical stress, vulcanized rubber will return to its original shape once the stress is removed.

• It's denser and heavier, and when exposed to mechanical stress, vulcanized rubber will return to its original shape once the stress is removed.

• It's denser and lighter, and when exposed to mechanical stress, vulcanized rubber will return to its original shape once the stress is removed.

• It's denser and heavier, and when exposed to mechanical stress, vulcanized rubber will not return to its original shape once the stress is removed.

Which of the following is true about vulcanized and unvulcanized rubber?

• Vulcanized rubber is less elastic than unvulcanized rubber

• Vulcanized rubber become soft and sticky easily compared to unvulcanized rubber

• Vulcanized rubber is stronger than unvulcanized rubber

• Vulcanized rubber is more easily oxidised than unvulcanized rubber

A student carried out an experiment to investigate the

elasticity of natural rubber and vulcanised rubber by

using the same sized rubber strips. Which strip will snap first if the mass of the weight continues to increase?

• M

• N

What should be done to natural rubber to produce tyres that are harder and more heat resistant?

• heat with sulphur

• add iron wire

• add ammonia solution

• add ethanoic acid