Rubber

Which substance is a natural polymer?

• polythene

• polyisoprene

• polypropene

• polyvinyl chloride

A rubber tapper finds that latex coagulates after several hours. What substance should be added into the latex to prevent it from coagulating?

• Formic acid

• Sodium chloride solution

• Ammonia solution

• Nitric acid

Charles Goodyear (December 29, 1800 – July 1, 1860) was an American self-taught chemist and manufacturing engineer who developed vulcanized rubber.

Nowadays in industrial vulcanization, latex is heated or exposed to _______________ to produced vulcanized rubber.

• ammonia solution

• disulphur dichloride

• concentrated hyrdochloric acid

• methanoic acid

The aircraft tyres are made from vulcanized rubber. What property of vulcanized rubber makes it suitable to be used for making these aircraft tyres?

• it resist to oxidation

• it is harder and stronger

• it can maintain their elasticity

• it can take the tremendous stress and strength

Substance P turns white latex milk into yellow solid. What is substance P?

• Ammonia solution

• Ethanoic acid

• Potassium hydroxide solution

• Potassium chloride solution

A lorry wants to transfer latex from a rubber estate to a rubber factory. Which substance can be added to the latex to prevent it from coagulating?

• Distilled water

• Tetrachloromethane

• Acetic acid

• Diluted sodium hydroxide solution

Which of the following is the correct structure of vulcanised natural rubber?

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Which of the following is the monomer of natural rubber?

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The protein membrane of natural rubber is surrounded by negative charge. What is the name of a process if the natural rubber is added with ethanoic acid?

• Vulcanisation

• Polymerisation

• Coagulation

• Hydrogenation

Which of the following is not the property of natural rubber?

• Sensitive to heat

• Elasticity decreases over time

• Easily oxidized by air

• Hard and brittle