Problem 79 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following statements about carbon fibres are correct? (1) They can be made from viscose rayon (2) They are used for making nose tips of missiles (3) They have low thermal conductivity and used as insulators (4) They are used for making components of bone plates Select the correct answer. (a) 1,2 and 3 (b) 2 and 3 only (c) 1,2 and 4 (d) 2 and 4 only

Step-by-Step Solution

Answer

Option (c) 1, 2, and 4 are correct.

Step 1: Analyze Each Statement

We need to review each of the four given statements about carbon fibers to determine their validity: 1. Carbon fibers can indeed be made from viscose rayon, which is a precursor material used in their production. 2. Carbon fibers are known for their high strength and heat resistance, making them suitable for use in critical aerospace applications such as missile nose tips. 3. Carbon fibers typically have high thermal conductivity rather than low, making them unsuitable as insulators. 4. Carbon fibers are used in medical applications, including making components of bone plates due to their biocompatibility and high strength.

Step 2: Evaluate Each Option

We now compare our analysis with each of the provided options: - Option (a) includes Statements 1, 2, and 3. Statement 3 is incorrect, so this option is incorrect. - Option (b) includes Statements 2 and 3. Again, Statement 3 is incorrect, so this option is incorrect. - Option (c) includes Statements 1, 2, and 4. All these statements have been verified as correct. - Option (d) includes Statements 2 and 4. While these statements are correct, it excludes Statement 1, which is also correct, making this option less comprehensive than option (c).

Step 3: Conclusion

After evaluating all options, Option (c), which includes Statements 1, 2, and 4, contains all the correct statements regarding carbon fibers. This is the most complete and accurate option, considering the analysis from previous steps.

Key Concepts

Viscose Rayon

Viscose rayon is a fascinating material that plays a critical role in creating carbon fibers. These carbon fibers are renowned for their incredible strength and versatility. Viscose rayon is a type of artificial silk, made from wood pulp or other natural sources of cellulose. It undergoes a series of chemical processes including spinning and carbonization.

• In the carbonization step, viscose rayon is heated to very high temperatures, causing it to decompose and form a carbon-rich structure.
• This process creates fibers that have high tensile strength and minimal weight, making them perfect for various industrial uses.
• The transformation from viscose rayon to carbon fiber is crucial to achieving the superior properties that carbon fibers offer.

Thus, viscose rayon is not just an ordinary material but an essential precursor in producing the extraordinary carbon fibers used in many advanced applications.

Aerospace Applications

Carbon fibers are critical in aerospace applications due to their exceptional qualities such as high strength-to-weight ratio and outstanding thermal resistance. This means they can withstand extreme forces and environments, which are often encountered in aerospace settings.

• Missiles and other aerospace technologies often employ carbon fibers for components like nose tips because they must endure high speeds and extreme temperatures without compromising structural integrity.
• The lightweight nature of carbon fibers contributes to fuel efficiency, an essential factor in aerospace design.
• Their resilience under pressure is valuable for developing safer and more durable aerospace structures.

Thus, carbon fibers are indispensable in advancing aerospace technology and improving the performance and safety of missile systems and aircraft.

Medical Applications

In the medical field, carbon fibers are appreciated for their biocompatibility and mechanical properties. This allows them to be seamlessly integrated into the human body without causing adverse reactions.

• They are commonly used in creating components for bone plates, which are crucial in surgical procedures for bone repair and reconstruction.
• The usage of carbon fibers reduces the risk of infection and inflammation, making them a preferred material for patients needing implants.
• Additionally, their lightweight and durable nature ensures that implants function efficiently without adding unnecessary burden to the body.

Therefore, carbon fibers in medical applications represent a leap forward in creating more effective, patient-friendly medical solutions.

High Strength Material

Carbon fibers are celebrated for being a high strength material, often compared to steel, yet they are much lighter. They exhibit exceptional mechanical properties that are crucial in many industries.

• Products made from carbon fibers can endure substantial stress without deforming, making them ideal for high-performance environments.
• Despite their strength, they are easily molded during manufacturing, allowing custom shapes and designs.
• The robustness of carbon fibers ensures that they maintain their properties even under repetitive stress and strain, ensuring longevity of the products they form.

As a high strength material, carbon fibers continue to play a vital role in innovation across various fields, including automotive, sports, and more.