Question

The trimer of acetaldehyde is known as (a) formalin (b) trioxane (c) paraldehyde (d) metaldehyde

Short answer

(a) Formalin (b) Trioxane (c) Paraldehyde (d) Metaldehyde Answer: (c) Paraldehyde

Step-by-step solution

Understand what a trimer is

A trimer is a molecule formed by the combination of three smaller molecules (monomers) of the same kind. In this case, we are looking for a molecule that is formed by combining three acetaldehyde molecules.

Know the structure of acetaldehyde

Acetaldehyde is an organic compound with the chemical formula CH3CHO. It is a simplest aldehyde and consists of a methyl group (-CH3) and an aldehyde group (-CHO).

Evaluate the given options

(a) Formalin is a 37% solution of formaldehyde in water and not a trimer of acetaldehyde. (b) Trioxane (C3H6O3) is a cyclic trimer of formaldehyde (not acetaldehyde) formed by a reaction between three formaldehyde molecules. (c) Paraldehyde (C6H12O3) is a cyclic trimer of acetaldehyde and is formed by the combination of three acetaldehyde molecules. (d) Metaldehyde (C8H16O4) is a cyclic tetramer of acetaldehyde and is formed by the combination of four acetaldehyde molecules.

Identify the correct option

Based on our analysis of the given options, the correct trimer of acetaldehyde is paraldehyde (C6H12O3). So, the correct answer is (c) paraldehyde.

Key concepts

Organic Chemistry

The field of organic chemistry is a branch of chemistry that focuses on the study of carbon-containing compounds. These compounds, known as organic molecules, often include other elements like hydrogen, oxygen, nitrogen, sulfur, and phosphorus.

Organic chemistry is foundational because it explains the structure, properties, and reactions of organic materials. These compounds are crucial for a wide range of products, from plastics and pharmaceuticals to natural substances and industrial chemicals.

One of the main perspectives in organic chemistry is understanding how molecules are built and how they interact. It distinguishes molecules based on their functional groups, which are specific groupings of atoms within molecules that have particular chemical properties. Aldehydes, for instance, are characterized by the presence of a carbonyl group (-CHO) bonded to a hydrogen atom.

Organic chemistry, therefore, not only lets us comprehend how these molecules behave but also allows us to synthesize new compounds for various applications, improving everything from medication efficacy to material properties.

Aldehyde Structure

Aldehydes are a category of organic compounds with the characteristic functional group of a carbonyl center (C=O) bonded directly to a hydrogen atom and an R group (which can be a hydrogen or any hydrocarbon chain).

This gives aldehydes their general formula of RCHO. The simplest aldehyde is formaldehyde, where the R group is a hydrogen atom, and another common aldehyde is acetaldehyde, where the R group is a methyl group (-CH3).

Aldehydes play crucial roles in organic reactions and are known for their distinct, often sharp odors. The carbonyl group is highly reactive, making aldehydes key reactants in various chemical reactions, including those used to produce resins, plastics, and drugs.

Their reactivity also makes them important intermediates in many biosynthetic pathways within living organisms. The structure influences their chemical behavior significantly, making aldehydes versatile components in both biological and industrial contexts.

Cyclic Trimer

A cyclic trimer is a compound formed when three identical molecules (monomers) join together in a cyclic structure. This trimer formation is different from linear combinations where molecules simply link in a chain.

In the case of acetaldehyde, its cyclic trimer is known as paraldehyde. By combining three acetaldehyde molecules, a ring-like structure is formed, which is chemically denoted as C6H12O3.

Cyclic trimers can exhibit unique properties as compared to their linear counterparts. They often have different physical characteristics, like boiling points and solubility, due to the geometric constraints of the cyclic arrangement.

Understanding how trimers form and their resultant structures is valorized in different fields, from materials science to pharmacology. In practical applications, cyclic trimers like paraldehyde can be used as solvents or in chemical synthesis, showing the versatility and utility of these structures.