The use of CFCs as a blowing agent has application in

1. Analyze the question

The question asks for the specific industrial application of Chlorofluorocarbons (CFCs) when used as a "blowing agent."

2. Explain the concept

• What are CFCs? CFCs are organic compounds containing carbon, chlorine, and fluorine. They were historically used in many applications due to their stability and low toxicity.
• What is a "blowing agent"? A blowing agent is a substance used to produce a cellular structure (like bubbles or pores) in a plastic or rubber matrix. This process is known as "foaming."
• The Process: When a blowing agent is added to a polymer (like polyurethane), it vaporizes or releases gas during the manufacturing process. This gas creates tiny bubbles within the material, turning it into a lightweight, insulating foam.

3. Show the solution

• Evaluating the options: • A. Foam industry: CFCs were widely used to create polyurethane foams (like those in mattresses, upholstery, and insulation) because they could easily turn into gas and expand the plastic into a foam structure. This is the definition of a blowing agent. • B. Tyre industry: Tyres are made through vulcanization and molding; they do not require blowing agents to create a foam structure. • C. Refrigerant: While CFCs were famously used as refrigerants in fridges and air conditioners, this is a different application. Being a refrigerant relies on the gas's ability to absorb and release heat during phase changes, not its ability to create a foam structure. • D. Propellant: CFCs were used as propellants in aerosol cans (like hairspray), but this is also a different application based on the pressure of the gas to push liquid out of a container.

Since the question specifically asks for the application of CFCs as a blowing agent, the correct context is the production of foam.

4. Identify the answer

The correct option is A.

5. Exam Tip

When you see questions about CFCs, remember they have three major historical uses: Refrigerants (cooling), Propellants (aerosols), and Blowing agents (foam). Always read the question carefully to see which specific function is being described!