In chemistry, what is the full form of the abbreviation IUPAC used for the main international body of pure and applied chemistry?

Introduction / Context:
The abbreviation IUPAC appears very frequently in school and college chemistry textbooks, on chemical nomenclature charts, and in scientific literature. Many students remember the letters but are not fully clear about the exact words behind the abbreviation and the role of this organization. This question tests your knowledge of the correct full form of IUPAC and the idea that it represents an international authority that standardizes chemistry related rules.

Given Data / Assumptions:

• The abbreviation given is IUPAC.
• The context is chemistry and standardization of names and symbols.
• We assume the question refers to the official global body responsible for pure and applied chemistry.

Concept / Approach:
The approach is to recall or recognize what each letter in IUPAC stands for. IUPAC is known for setting rules for naming organic and inorganic compounds, standardizing atomic weights, and publishing recommendations for symbols and terminology. Therefore, the correct option should mention an international union that deals with both pure and applied chemistry, not something limited to a single country or to an unrelated field. We simply compare each option with this known concept.

Step-by-Step Solution:
Step 1: Break down IUPAC into I, U, P, A, and C. Step 2: I stands for International, U stands for Union, P stands for Pure, A stands for Applied, and C stands for Chemistry. Step 3: Look for an option that matches exactly this phrase and represents a worldwide body. Step 4: Option A reads International Union of Pure and Applied Chemistry, which matches perfectly. Step 5: Confirm that no other option correctly captures both the international character and the focus on pure and applied chemistry.

Verification / Alternative check:
A quick way to verify is to think about how chemical names are written in textbooks. Nomenclature systems are often described as IUPAC nomenclature. The organization that publishes such systems must be an international union, not a national body. Also, in many exam questions and in competitive exam guides, the full form of IUPAC is explicitly written as International Union of Pure and Applied Chemistry. None of the other options are widely known or used in chemistry, which confirms that option A is correct.

Why Other Options Are Wrong:
Option B, Indian Union of Pure and Applied Chemistry, is incorrect because IUPAC is not restricted to India and is clearly international. Option C, International Union of Postal and Application Corporation, looks like a random combination of words and has no connection to chemistry. Option D, International University of Poland and Cambodia, also looks artificial and refers to a university instead of a union, and it does not mention chemistry at all. These incorrect options are designed to distract students who only vaguely remember some of the letters.

Common Pitfalls:
A common mistake is to assume that I stands for Indian or that the word applied is not part of the name, leading to partially correct guesses. Another pitfall is to focus only on the first word, International, and then choose any option that begins with that word without checking the full phrase. Students may also confuse IUPAC with other international organizations and pick an option that sounds official but is not related to chemistry. Careful reading of every word in each option helps avoid these errors.

Final Answer:
The full form of IUPAC in chemistry is International Union of Pure and Applied Chemistry.