Problem 128 - A Complete Resource Book in Chemistry for JEE Main

Question

Which is correctly matched here? List I 1\. Aniline yellow 2\. Phenyl azo \(\beta\) - naphthol 3\. \(\mathrm{p}\)-nitro acetanilide 4\. Mohr's salt The correct matching is? 1 2 4 (a) (ii) (i) (iv) (iii) (b) (i) (ii) (iv) (iii) (c) (ii) (i) (iii) (iv) (d) (i) (iv) (ii) (iii)

Step-by-Step Solution

Answer

Option (d) is the correct match: (i), (iv), (ii).

Step 1: Analyze List I

Review the compounds listed in List I: 1. Aniline yellow, 2. Phenyl azo \( \beta \) - naphthol, 3. \( \mathrm{p} \)-nitro acetanilide, 4. Mohr's salt. Identify each compound and associate them with their properties or uses.

Step 2: Understand the Options in List II

Recognize what each compound in List I is generally associated with. For instance, aniline yellow is a dye, phenyl azo \( \beta \)-naphthol is a type of azo dye, \( \mathrm{p} \)-nitro acetanilide is a chemical compound related to analgesics, and Mohr's salt is used as a standard in redox reactions.

Step 3: Match Each Item with the Correct Option

Based on the associations identified, match List I with List II. Consider the common uses, chemical nature, or standard naming conventions to determine which belongs to which matching pattern.

Step 4: Match Evaluation

For 'Aniline yellow', which is dye-related, (i) is correct. For 'Phenyl azo \( \beta \)-naphthol', a dye-related option (ii) makes sense. 'Mohr's salt', used in redox reactions, would likely match with (iv). There doesn't seem to be a defined match for \( \mathrm{p} \)-nitro acetanilide in the presented options without further context.

Step 5: Rule out Incomplete or Incorrect Matches

Compare the given options with the matches found in Step 4: (a) seems to be a mix and does not properly match Mohr's salt. (b) partially matches as (ii) and (iv), matching 2 and 4, but misses exact correspondence. (c) doesn't match correctly due to including (iii) incorrectly. (d) matches correctly with 1 to (i), 4 to (iv), and 2 to (ii).

Key Concepts

Aniline Yellow

Aniline yellow is a popular synthetic dye that was among the first of its kind to be made available commercially. This compound belongs to the family of azo dyes, which are characterized by their vibrant colors, due to the presence of the azo group

• Known for its bright yellow hue, aniline yellow is commonly used to color textiles, paper, and even in the chemical industry.
• The compound owes its color properties to the azo group (\( \text{N} = \text{N} \)), which forms a part of its molecular structure.
• Azo dyes, like aniline yellow, are also used as indicators in various chemical reactions due to their color change under different conditions.

An important note is that some azo dyes, including aniline yellow, can have health impacts if not handled properly, thus caution is advised in their application.
With its role in historical dye processes and modern applications, aniline yellow remains an important substance in industrial chemistry.

Phenyl Azo Beta-naphthol

Phenyl azo beta-naphthol is another type of azo dye, specifically used for its vivid coloring abilities and its role in testing and analysis

• This compound is often used in textile dyeing and serves as an intermediate for the synthesis of other dyes and pigments.
• The classic structure of azo dyes includes the azo linkage (\( -\text{N}=\text{N}- \)) connected to aromatic rings, which is a key feature in phenyl azo beta-naphthol.
• The vibrant reds and oranges provided by this dye are used in various products around us, from clothes to inks.
• In laboratories, phenyl azo beta-naphthol can also be part of qualitative analysis work, helping chemists understand interaction between chemical substances through color change.

Playing a dual role in both industrial and analytical fields, phenyl azo beta-naphthol exemplifies the versatility of azo dye chemistry.

Mohr's Salt

Mohr's salt, known scientifically as ferrous ammonium sulfate, is a double salt of iron commonly used in laboratories for various experiments

• Mohr's salt has been a staple in redox titrations thanks to its stable crystalline nature and its ability to serve as a source of ferrous ions (Fe\(^{2+}\)).
• The structure of Mohr's salt is defined by the chemical formula \([\text{Fe}\text{(SO}_4)_2 \cdot \text{(NH}_4\text{)}_2\text{SO}_4 \cdot 6\text{H}_2\text{O}]\).
• Its stability makes it a prime choice for consistent results in quantitative analysis and education regarding redox reactions and stoichiometry.

Mohr's salt remains indispensable in education and research, balancing practicality with precision.

Chemical Matching

Chemical matching is an essential concept in chemistry where the objective is to accurately associate chemical substances with their correct applications or related components

• The goal of chemical matching is to foster a deeper comprehension of chemical properties, uses, and their respective characteristics.
• This skill is particularly useful in academic exercises, allowing students to learn by connecting chemical structures to their practical uses.
• The principles of chemical matching can aid in developing a systematic approach to learning chemistry and understanding chemical interactions.

By mastering chemical matching, learners can better visualize how seemingly disparate chemical agents connect to form the basis of many familiar and industrial procedures.