Problem 115 - Chemistry The Molecular Science

Question

Locate the grid for Question \(115 .\) Each of its nine lettered boxes contains an item that can be used to fill in the blanks that follow. Items may be used more than once and there may be more than one correct item for a blank. Place the letter(s) of the correct selection(s) on the appropriate line. (a) A triglyceride (b) Final oxidation product of a primary alcohol (c) Condensation polymerization monomer (d) Segment of an addition polymer molecule (e) Initial oxidation product of a primary alcohol (f) Contains an amide bond (g) Addition polymerization monomer

Step-by-Step Solution

Answer

(a) Identify a triglyceride; (b) Look for a carboxylic acid; (c) Identify a condensation monomer; (d) Find a polymer segment; (e) Look for an aldehyde; (f) Choose an amide bond item; (g) Find a monomer with a double bond.

Step 1: Interpret the Exercise

We are given a list of items identified by letters and asked to match them with given descriptions. Our task involves picking the correct letter for each description.

Step 2: Match Item for (a) A triglyceride

A triglyceride is a lipid molecule composed of glycerol esterified with three fatty acids. In the options, look for an item that is a triglyceride or structurally represents one.

Step 3: Match Item for (b) Final oxidation product of a primary alcohol

The complete oxidation of a primary alcohol results in the formation of a carboxylic acid. Identify the item representing a carboxylic acid.

Step 4: Match Item for (c) Condensation polymerization monomer

In condensation polymerization, monomers join together, releasing small molecules. Look for a monomer that can undergo this type of polymerization.

Step 5: Match Item for (d) Segment of an addition polymer molecule

An addition polymer molecule is formed by the addition of monomer units without the loss of any atoms. Identify the structure that is part of a polymer chain.

Step 6: Match Item for (e) Initial oxidation product of a primary alcohol

The initial oxidation reaction of a primary alcohol typically produces an aldehyde. Find the item that corresponds to an aldehyde group.

Step 7: Match Item for (f) Contains an amide bond

Amide bonds are found in proteins and polymers like nylon. Choose the item that has this type of bond.

Step 8: Match Item for (g) Addition polymerization monomer

Monomers for addition polymerization are typically unsaturated or have a double bond. Identify monomers with this characteristic.

Key Concepts

Condensation Polymerization

Condensation polymerization is a process where monomer molecules combine to form a polymer while releasing small molecules like water or methanol. This is a step-growth polymerization, meaning the polymer continues to grow as monomers keep interacting. This process is common in creating materials like polyesters and nylons.
In such reactions, each monomer usually has two functional groups which are reactive sites. When these sites react, a small molecule is eliminated, allowing the monomers to bond.

• Example: The formation of nylon from diamine and dicarboxylic acid, where water is released as a byproduct.
• Important note: Due to the byproduct, the efficiency and purity of the polymer can vary based on conditions like temperature and concentration.

This knowledge is essential for understanding how various plastics and synthetic fibers are manufactured.

Addition Polymerization

Addition polymerization, also known as chain-growth polymerization, involves monomers with double bonds, such as alkenes, combining without the loss of any atoms. This kind of polymerization is vital for making common plastics like polyethylene and polypropylene.
The process starts with the activation of a monomer, often using a catalyst. This active monomer reacts with others, forming a long polymer chain. Key characteristics of addition polymerization include:

• Fast reaction rates compared to condensation polymerization.
• No byproducts, which makes the process efficient and clean.

Understanding addition polymerization helps in identifying how bulk and specialty polymers are synthesized, especially in the commercial production of various materials.

Primary Alcohol Oxidation

The oxidation of a primary alcohol is a stepwise process, crucial in organic chemistry for synthesizing aldehydes and carboxylic acids. Initially, when a primary alcohol undergoes oxidation, an aldehyde is formed. With further oxidation, this aldehyde converts into a carboxylic acid.
This transformation is significant in both laboratory settings and industrial applications. Key points include:

• Initial formation of aldehydes, which have a carbonyl group bonded to a hydrogen atom.
• Use of specific oxidizing agents, such as potassium dichromate or pyridinium chlorochromate (PCC), to carry out the reactions.

These reactions are fundamental in creating various organic compounds and intermediates necessary for producing drugs, flavors, and perfumes.

Amide Bonds

Amide bonds are a type of covalent bond formed between an amine group and a carboxyl group. They are most commonly found in proteins, where they link amino acids in long chains. In synthetic chemistry, amide bonds are also key building blocks in polymers like nylon.
Amide bonds are characterized by their stability and resistance to hydrolysis, making them ideal for structural materials in biological and synthetic contexts. Important aspects include:

• Formation: Typically involves a condensation reaction releasing a molecule of water.
• Applications: Beyond proteins, they are used in engineering plastics and pharmaceuticals.

Learning about amide bonds opens up understanding the fundamental composition of proteins as well as the production of various synthetic fibers.