Problem 49 - A Complete Resource Book in Chemistry for JEE Main

Question

The substance used to harden the rubber for tyre manufacture is (a) \(\mathrm{CaC}_{2}\) (b) wax (c) carbon black (d) 1,3 -butadiene

Step-by-Step Solution

Answer

The substance used to harden rubber in tyre manufacturing is carbon black (c).

Step 1: Identify the Role of the Substance

In tyre manufacturing, certain substances are used to improve the properties of rubber. Specifically, the hardening process is important for enhancing the durability and strength of the rubber to withstand various conditions during use.

Step 2: Examine Each Option

Let's analyze each option: - (i) \( \mathrm{CaC}_{2} \) (ii) Wax (iii) Carbon black (iv) 1,3-butadieneCarbon black is commonly used as a reinforcing agent that enhances the durability and hardness of rubber.

Step 3: Confirm the Correct Substance

The main substance known for hardening rubber by enhancing its mechanical properties is carbon black. It improves abrasion resistance and increases the tensile strength of rubber.

Key Concepts

Tyre Manufacturing

Tyre manufacturing is an intricate process that involves several stages, each aimed at creating a product that is safe, durable, and reliable. Tyres need to withstand various conditions such as high speeds, extreme temperatures, and different terrains. This requires a combination of materials and processes to ensure quality and performance.

One of the pivotal aspects of tyre production is the formulation of rubber compounds. These compounds are designed to provide specific properties needed for different types of tyres, like those for passenger cars versus industrial machines. The process typically begins with selecting natural or synthetic rubber, which is then mixed with additives.

Additives such as sulfur, accelerators, and carbon black are mixed into the rubber during a process called "compounding." This process allows for the uniform distribution of these materials in the rubber matrix. It is crucial because it enhances the mechanical properties required for the final product, ensuring tyres that are safe and efficient from a performance standpoint.

Carbon Black

Carbon black is a reinforcing filler used extensively in the rubber industry, particularly in tyre manufacturing. It plays a vital role in strengthening the rubber and enhancing its performance characteristics.

Among its various functions, carbon black significantly improves the wear resistance of the tyre. This means a longer lifespan for the tyre, as it becomes more resistant to cracking and abrasive wear on the road. Additionally, carbon black increases the tensile strength, a critical feature for tyres that need to endure the stresses of everyday driving.

Moreover, carbon black is instrumental in improving the thermal conductivity of rubber, allowing heat generated during driving to dissipate effectively. This reduces the chances of tyre failure caused by overheating. Overall, it is a crucial element that not only contributes to the durability of tyres but also aids in ensuring safety.

Mechanical Properties of Rubber

The mechanical properties of rubber determine how well a tyre can perform under various conditions. These properties include durability, flexibility, and strength, all of which are essential for the optimal performance of tyres.

Durability refers to the tyre's ability to withstand wear and tear over time. A tyre needs to maintain its integrity despite repeated use on different surfaces. Flexibility is important because it allows the tyre to absorb shocks from uneven surfaces, providing a smoother and more comfortable ride.

Strength encompasses several parameters, including tensile strength and elasticity, which signify how well the tyre handles stretching forces without breaking. Enhancing these properties is critical, and it can be achieved by incorporating certain materials and additives during manufacturing. For instance, carbon black is known to enhance tensile strength, while other additives may improve elasticity or abrasion resistance.

Ultimately, these properties ensure that tyres are not only functional but also safe and efficient under a variety of driving conditions.