Understanding Rubber: Natural vs. Vulcanized

What is a key characteristic of natural rubber?

• It is highly resistant to heat.

• It is easily oxidized.

• It has a high melting point.

• It is not elastic.

Why is natural rubber soft and less elastic?

• Because it has strong chemical bonds between molecules.

• Because it is highly cross-linked.

• Because it has weak forces of attraction between molecules.

• Because it is made of short polymer chains.

What is the purpose of vulcanization?

• To make rubber more flexible.

• To improve the rubber's elasticity and strength.

• To increase the rubber's melting point.

• To make rubber more soluble in water.

What is added to rubber during the vulcanization process?

• Oxygen

• Sulfur

• Chlorine

• Nitrogen

How does vulcanization affect the properties of rubber?

• It lowers the rubber's melting point.

• It decreases the rubber's resistance to heat.

• It makes rubber less elastic.

• It makes rubber more resistant to oxidation.

Which property is NOT improved in vulcanized rubber compared to natural rubber?

• Heat resistance

• Solubility in water

• Oxidation resistance

• Elasticity

What is a key difference between natural and vulcanized rubber?

• Natural rubber has a higher melting point.

• Vulcanized rubber has sulfur cross-links.

• Vulcanized rubber is less elastic.

• Natural rubber is more heat resistant.

What should be included in a diagram explaining vulcanized rubber?

• A depiction of sulfur cross-links.

• A representation of water molecules.

• A diagram of rubber dissolving in benzene.

• A chart showing temperature changes.

Why are sulfur cross-links important in vulcanized rubber?

• They allow the rubber to dissolve in organic solvents.

• They prevent the polymer chains from slipping past each other.

• They make the rubber more soluble in water.

• They decrease the rubber's elasticity.

What is the result of adding sulfur to rubber molecules?

• The rubber becomes less sticky.

• The rubber's melting point decreases.

• The rubber becomes more elastic and stronger.

• The rubber becomes more soluble in water.