Question

Dimethyl phthalate and ethylene glycol react to form (a) Nylon-6 (b) Nylon-6,6 (c) Dacron (d) neoprene

Short answer

(c) Dacron

Step-by-step solution

Identify Reactants

Recognize the given reactants in the problem: dimethyl phthalate and ethylene glycol. These are typical components used in the formation of polyesters.

Recall Polyester Formation

Understand that dimethyl phthalate and ethylene glycol often react together in a condensation polymerization process to form a polyester known as polyethylene terephthalate (PET), commonly referred to as Dacron.

Eliminate Incorrect Options

Review the options provided in the question. Nylon-6 and Nylon-6,6 are types of polyamides, and neoprene is a type of synthetic rubber. These materials do not typically result from the combination of dimethyl phthalate and ethylene glycol.

Match Reaction Product with Options

Since the reaction between dimethyl phthalate and ethylene glycol forms Dacron, which is listed as an option, identify it as the correct answer for this chemical reaction.

Key concepts

Condensation Polymerization

Condensation polymerization is a chemical process used to create complex molecules called polymers. During this method, monomer units join together and release a small molecule as a byproduct, often water or methanol. This method can differ from addition polymerization, where no small molecules are released.

When considering condensation polymerization, it's important to understand the following:

• Monomers containing functional groups such as hydroxyl (-OH) and carboxyl (-COOH) groups are typically involved in the reaction.
• These functional groups react to form a covalent bond, which links the monomers together in a chain.
• The reaction produces repeat units, and a byproduct is eliminated as the polymer grows.

A classic example of a product formed through condensation polymerization is polyethylene terephthalate (PET), commonly known as Dacron. Understanding this process helps in identifying the characteristics of polymers formed in such reactions.

Polyethylene Terephthalate

Polyethylene terephthalate, commonly abbreviated as PET, is a type of polyester that is widely used in various applications. It is formed through condensation polymerization, primarily involving two monomers: ethylene glycol and terephthalic acid. When dimethyl phthalate is used, it acts as the equivalent source of terephthalic acid.

PET is beloved for its durable and flexible properties and is most often found in items such as:

• Fibers for clothing and textiles (commonly known by the brand name Dacron)
• Containers and packaging materials, such as bottles
• Engineering resins used in electronics

The formation process of PET involves ethylene glycol's hydroxyl group reacting with dimethyl phthalate's ester group, forming a continuous polymer chain and releasing methanol as a byproduct. Understanding these reactions is crucial when studying the production and application of synthetic materials.

Chemical Reaction Identification

When identifying chemical reactions, it's important to recognize the reactants and the type of product formed. The exercise involves recognizing that the product formed from dimethyl phthalate and ethylene glycol is not a polyamide such as Nylon, nor is it a synthetic rubber like neoprene. Instead, these reactants form a polyester.

Here’s how you can identify the reaction correctly:

• Understand the nature of reactants: Dimethyl phthalate is typically a precursor for terephthalic acid, while ethylene glycol is a common diol.
• Recognize the polymerization type: Condensation reactions involving these specific reactants commonly form polyesters.
• Recall common products: With these reactants, Polyethylene Terephthalate or Dacron is formed through condensation polymerization.

Properly identifying chemical reactions involves matching reactants with potential products and eliminating incorrect options based on your chemical knowledge and reaction types.