Problem 210 - A Complete Resource Book in Chemistry for JEE Main

Question

Bakelite is obtained from phenol by reacting with [2008] (a) \(\left(\mathrm{CH}_{2} \mathrm{OH}\right)_{2}\) (b) \(\mathrm{CH}_{3} \mathrm{CHO}\) (c) \(\mathrm{CH}_{3} \mathrm{COCH}_{3}\) (d) \(\mathrm{HCHO}\)

Step-by-Step Solution

Answer

The correct answer is (d) \(\text{HCHO}\).

Step 1: Understand What Bakelite Is

Bakelite is a type of synthetic polymer that is obtained from phenol. It was the first plastic made from synthetic components and is known for being strong and heat-resistant.

Step 2: Recall the Reaction to Form Bakelite

The production of Bakelite involves the reaction of phenol with formaldehyde under certain conditions. This process forms a phenol-formaldehyde resin, which is what Bakelite is made of.

Step 3: Identify the Chemical Formula for Formaldehyde

Formaldehyde is a simple aldehyde with the formula \(\text{HCHO}\). It is commonly used in producing phenol-formaldehyde resins, such as Bakelite.

Step 4: Match the Correct Option

Given the options, the correct formula for formaldehyde is option (d) \(\text{HCHO}\). This is the compound that reacts with phenol to form Bakelite.

Key Concepts

Phenol

Phenol is an aromatic compound that plays a crucial role in the formation of many industrial products. It has a benzene ring bonded to a hydroxyl group, which gives phenol its unique properties. This compound is notably one of the fundamental building blocks for the production of plastics, including Bakelite.

Here are some key points about phenol:

• Chemical formula: C₆H₅OH.
• It is mildly acidic and can cause chemical burns.
• Used in the production of pharmaceuticals, resins, and as a disinfectant.

In the context of Bakelite, phenol is reacted with another compound to initiate polymerization. This reaction leads to the formation of complex resin structures.

Formaldehyde

Formaldehyde is a simple and essential organic compound with significant industrial use. It appears as a colorless gas, recognizable by its pungent smell. The chemical formula for formaldehyde is HCHO, and it's known for being involved in a variety of chemical processes.

Regarding its uses, formaldehyde stands out for the following reasons:

• It acts as a precursor for many other compounds and materials.
• It's a critical ingredient in producing industrial resins and building materials.
• In the formation of Bakelite, formaldehyde reacts with phenol to create a durable synthetic plastic.

Care must be taken when handling formaldehyde due to its potential health hazards. It is important in the synthesis of phenol-formaldehyde resin, which is crucial for Bakelite formation.

Synthetic Polymer

Synthetic polymers are human-made chains of repeating chemical units, created to mimic and improve upon natural materials. They have a wide range of applications due to their customizable properties. Examples of synthetic polymers include nylon, polyester, and notably, Bakelite.

Why synthetic polymers matter:

• They can be crafted to be more durable, flexible, or heat-resistant than their natural counterparts.
• They are essential in the manufacturing of everyday products, from clothing to electronics.
• The ability to modify their structure allows for innovations in technology and materials science.

Bakelite, one of the earliest synthetic polymers, marked a new era in material science by providing a strong, heat-resistant alternative to materials previously available.

Phenol-Formaldehyde Resin

Phenol-formaldehyde resin is the first completely synthetic polymer ever created. It arises from the reaction between phenol and formaldehyde and forms the foundation for various industrial applications, most famously Bakelite.

Some benefits of phenol-formaldehyde resin include:

• Exceptionally strong: It provides excellent mechanical strength compared to other early resins.
• Heat-resistant: Ideal for electrical applications due to its insulating properties.
• Versatile: Used in the production of plywood, countertops, and moldings.

This resin showcases the potential of combining different compounds to create materials with superior properties. Its development was a significant milestone and paved the way for the diverse use of resins in multiple domains.