The substance often used for vulcanization of rubber is?

Step 1: Analyze the question The question asks which substance is used for vulcanization of rubber.

Step 2: Explain the concept Natural rubber (latex from the rubber tree, common in Edo, Delta, and Ondo states) is made of long, tangled polymer chains of isoprene. On its own, it is:

• Soft and sticky in hot weather
• Brittle in cold weather
• Weak and not very elastic

Vulcanization is the process of heating rubber with sulphur. The sulphur forms cross-links (sulphur bridges) between the polymer chains. This makes the rubber:

• Harder and stronger
• More elastic and durable
• Resistant to heat and cold

Step 3: Evaluate the options

• A. Chlorine: Used for bleaching and water treatment, and in making PVC. It is not used to vulcanize rubber.
• B. Hydrogen peroxide: An oxidizing and bleaching agent. It has no role in cross-linking rubber.
• C. Sulphur: Correct. It forms the cross-links between the rubber chains.
• D. Tetraoxosulphate(VI) acid (H₂SO₄): Used in car batteries and fertilizer production. In rubber processing it may help coagulate latex, but it does not vulcanize rubber.

Step 4: Answer The correct option is **C.

Tip: Remember "Vulcanization = Sulphur" (think of the tough rubber in vehicle tyres). Also note that coagulation of latex uses a weak acid such as ethanoic acid, while vulcanization uses sulphur. JAMB often tests this distinction.