Question

This section contains multiple choice questions. Each question has 4 choices (a), (b), (c) and (d), out of which ONLY ONE is correct. Ester linkages are present in (a) teflon (b) orlon (c) nylon (d) terylene

Short answer

A. Teflon B. Orlon C. Nylon D. Terylene Answer: D. Terylene

Step-by-step solution

Understand Ester Linkage

Ester linkage is a functional group in organic chemistry that has the general structure R-C(=O)-O-R', where R and R' are any organic group. This linkage is formed during the reaction between an alcohol and a carboxylic acid to produce an ester.

Analyze the given materials

(a) Teflon: It is a type of polymer made from tetrafluoroethylene (CF2=CF2). The monomers in teflon are linked by carbon-carbon bonds and carbon-fluorine bonds, without any ester linkage present. (b) Orlon: It is an acrylic fiber made from acrylonitrile (CH2=CH-CN). The monomers in orlon are linked by carbon-carbon and carbon-nitrogen bonds, without any ester linkage present. (c) Nylon: It is a type of polyamide made from the reaction between a diamine and a dicarboxylic acid. The monomers in nylon are linked by carbon-nitrogen (amide) bonds, without any ester linkage present. (d) Terylene: It is a polyester made from the reaction between ethylene glycol (HO-CH2-CH2-OH) and terephthalic acid (HOOC-C6H4-COOH). The monomers in terylene are linked by ester linkages (R-C(=O)-O-R').

Identify the correct option

Since terylene contains ester linkages in its molecular structure, the correct answer is: (d) terylene

Key concepts

Understanding Organic Chemistry

Organic chemistry is a branch of chemistry that specializes in the study of the structure, properties, and reactions of organic compounds, which contain carbon. The carbon atoms form a strong backbone or framework to which other atoms like hydrogen, oxygen, and nitrogen can be attached.

Within organic chemistry, functional groups play a critical role as they determine the properties and reactivity of molecules. For instance, the ester functional group, which is central to the exercise question, consists of a carbonyl group adjacent to an ether linkage. This particular functional group is represented by the formula R-C(=O)-O-R', indicating the presence of an organic molecule R and R' attached to an oxygen atom via carbon.

The knowledge of organic chemistry is not just vital for solving multiple choice questions but is essential for understanding biological processes, developing pharmaceuticals, and designing materials with specific properties, such as the polymers discussed in the question.

Decoding the World of Polymers

Polymers are large molecules composed of repeating structural units called monomers. These monomers can be linked together in varied patterns to produce a vast array of polymers, each with its unique set of properties. Common examples of polymers include plastics, synthetic fibers, and elastomers.

Polymers can exhibit different types of linkages that determine their physical attributes and applications. For instance, in the exercise, we explored different polymers such as teflon, orlon, nylon, and terylene. These materials have wide-ranging uses, from non-stick cookware to resilient textiles, each due to the different linkages holding their monomers together.

In the context of our original exercise, understanding the type of linkage present in polymers is key to identifying their classification, like distinguishing terylene, a polyester with ester linkages, from nylon, a polyamide without any.

Functional Groups Are the Key

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. They are like the defining traits of chemical species, imparting identity and reactivity.

In organic chemistry, recognizing various functional groups, such as alcohols, carboxylic acids, amines, and esters, is crucial for predicting how a molecule will behave under different conditions. For example, ester linkages are known for giving certain materials their durability and resistance to environmental factors, which is why terylene is valued in the textile industry for its strong fibers that resist stretching and shrinking.

As noted in the exercise solution, identifying the presence of an ester linkage in terylene is essential to solving the problem. Functional groups, thus, are not just a concept but a lens through which chemists view and understand the molecular world.