Question

The decreasing ordcr of the priority of functional groups is (1) \(\mathrm{COO} \mathrm{I}>\mathrm{COCl}>\mathrm{CIIO}>\mathrm{CN}\) (2) \(\mathrm{COOII}>\mathrm{CIIO}>\mathrm{COCl}>\mathrm{CN}\) (3) COOII \(>\) CIIO \(>\) CN \(>\) COCl (4) \(\mathrm{COOII}>\mathrm{CN}>\mathrm{ClIO}>\mathrm{COCl}\)

Short answer

Option 1

Step-by-step solution

Identify the Functional Groups

First, identify the functional groups listed in each option: 1. \( \text{COO}, \text{COCl}, \text{CHO}, \text{CN} \)2. \( \text{COOH}, \text{CHO}, \text{COCl}, \text{CN} \)3. \( \text{COOH}, \text{CHO}, \text{CN}, \text{COCl} \)4. \( \text{COOH}, \text{CN}, \text{CHO}, \text{COCl} \)

Determine the Priority Order of Functional Groups

The priority order of functional groups according to IUPAC nomenclature from highest to lowest is: \( \text{COOH} > \text{COCl} > \text{CHO} > \text{CN} \).

Compare Each Option to the Correct Priority Order

Compare each option to the correct priority order: Option 1: \( \text{COO} > \text{COCl} > \text{CHO} > \text{CN} \) matches the order.Option 2: \( \text{COOH} > \text{CHO} > \text{COCl} > \text{CN} \) does not match.Option 3: \( \text{COOH} > \text{CHO} > \text{CN} > \text{COCl} \) does not match.Option 4: \( \text{COOH} > \text{CN} > \text{CHO} > \text{COCl} \) does not match.

Key concepts

Functional Groups

Functional groups are specific groupings of atoms within molecules that have their own characteristic properties. They play a crucial role in the field of organic chemistry, as they determine the chemical reactions that the compound can undergo. Some common functional groups include:

• Carboxyl group (COOH)
• Aldehyde group (CHO)
• Nitrile group (CN)
• Chlorocarbonyl group (COCl)

Understanding these groups is essential, as they form the basis for naming organic compounds. They help predict the behavior of molecules in chemical reactions.

IUPAC Nomenclature

The International Union of Pure and Applied Chemistry (IUPAC) nomenclature is a systematic way of naming chemical compounds. This system helps ensure that each compound has a unique and descriptive name. The IUPAC nomenclature for organic compounds typically involves the following steps:

1. Identify the longest carbon chain in the molecule.
2. Number the carbon atoms in the main chain, starting from the end closest to a functional group.
3. Identify and number the substituents (side chains and functional groups).
4. Combine the numbers and names of substituents with the base name of the compound, arranging substituents alphabetically.
The use of IUPAC nomenclature is critical for clear communication among chemists and for addressing the complex nature of organic chemistry.

Priority Order in Organic Chemistry

In organic chemistry, functional groups are assigned a priority order to resolve any ambiguity in naming compounds with multiple functional groups. The priority order follows a specific hierarchy set by IUPAC, where certain groups take precedence over others. For example:

• Carboxylic acids (COOH) have the highest priority.
• Next are acid halides (COCl).
• Then come aldehydes (CHO).
• Nitriles (CN) have a lower priority than the others mentioned here.

This priority order is essential for deciding how to name compounds, especially those with multiple functional groups. In the given exercise, adhering to this priority order helps in determining the correct answer.

Engineering and Medical Entrance Exams

A solid understanding of IUPAC nomenclature and the priority order of functional groups is vital for students preparing for engineering and medical entrance exams. These exams, such as the IIT-JEE (Joint Entrance Examination) for engineering and NEET (National Eligibility cum Entrance Test) for medical sciences, often feature questions on organic chemistry nomenclature. Mastering these concepts can:

• Increase the chance of scoring higher in the chemistry section.
• Build a solid foundation for future studies in science and engineering.
• Enhance problem-solving skills through the practice of step-by-step methods.

Therefore, a thorough grasp of these topics is not just about passing exams but also about unlocking further academic and professional opportunities.