CBSE Class 11th : Organic Chemistry - Chapter 12 (IUPAC System) Video Lecture

Ans. The IUPAC (International Union of Pure and Applied Chemistry) system is a set of rules and conventions used to name organic compounds systematically. It provides a standardized way to name and represent organic molecules, ensuring clarity and consistency in scientific communication.

Ans. The IUPAC system assigns priority to functional groups based on the concept of seniority. The functional group with the highest seniority is given the lowest locant number and is considered the principal functional group. The seniority of functional groups is determined by their respective classes, with higher classes having higher priority. For example, a carboxylic acid (class 1) takes priority over an alcohol (class 2) in naming a compound.

Ans. The steps involved in naming organic compounds using the IUPAC system are as follows: 1. Identify the longest continuous carbon chain in the molecule, called the parent chain. 2. Number the carbon atoms in the parent chain starting from the end closest to the highest priority functional group. 3. Identify and name the substituents attached to the parent chain. 4. Assign a locant number to each substituent based on its position on the parent chain. 5. Combine the substituent names with the parent chain name, using appropriate prefixes and suffixes. 6. Arrange the substituents in alphabetical order, ignoring any prefixes that indicate the number of substituents. 7. Use hyphens to separate numbers and commas to separate multiple identical substituents. 8. If multiple functional groups are present, assign priority and indicate their positions using locant numbers.

Ans. To name organic compounds with cyclic structures using the IUPAC system, the following steps can be followed: 1. Identify the parent ring by counting the number of carbon atoms in the ring. 2. Name the substituents attached to the ring, following the same rules as for acyclic compounds. 3. Assign locant numbers to the substituents based on their positions on the ring. 4. Combine the substituent names with the parent ring name, using appropriate prefixes and suffixes. 5. Arrange the substituents in alphabetical order, ignoring any prefixes that indicate the number of substituents. 6. Use hyphens to separate numbers and commas to separate multiple identical substituents.

Ans. When naming organic compounds with multiple functional groups using the IUPAC system, the functional groups are named and positioned using locant numbers. The functional group with the highest seniority is assigned the lowest locant number. If there are multiple functional groups of the same seniority, they are assigned locant numbers based on alphabetical order. The locant numbers are placed as prefixes before the parent chain name, separated by hyphens. The substituents are also named and positioned using locant numbers, following the same rules as for acyclic compounds.