Problem 93 - A Complete Resource Book in Chemistry for JEE Main

Question

Match the following: List I 1\. Iodoform 2\. Methyl salicylate 3\. Diethyl ether 4\. Hexachlorocyclohexane List II (i) Anaesthetic (ii) Antiseptic (iii) Insecticide (iv) Detergent (v) Pain balm

Step-by-Step Solution

Answer

Iodoform - Antiseptic, Methyl salicylate - Pain balm, Diethyl ether - Anaesthetic, Hexachlorocyclohexane - Insecticide.

Step 1: Analyze List I

Examine each compound in List I to determine their primary uses or properties. 1. **Iodoform**: Known for its antiseptic properties. Historically used in medicine for its disinfectant qualities. 2. **Methyl salicylate**: Often used in topical pain-relieving creams or ointments, it's primarily linked to pain relief or as a counterirritant. 3. **Diethyl ether**: Long-known as an anesthetic. Used historically to induce loss of consciousness/sensation. 4. **Hexachlorocyclohexane**: Commonly used as an insecticide. Known commercially as Lindane, it's used in agricultural settings.

Step 2: Analyze List II

Understand each term in List II to align with possible compounds from List I. (i) **Anaesthetic**: A substance that induces insensitivity to pain. (ii) **Antiseptic**: Used to prevent infection by killing or inhibiting the growth of pathogens. (iii) **Insecticide**: A chemical used to kill insects. (iv) **Detergent**: Used to remove dirt and grease, commonly in cleaning products. (v) **Pain balm**: Topically applied to relieve pain, often having warming properties.

Step 3: Match Compounds to Descriptions

Assign each compound in List I with the correct description from List II based on their properties. 1. **Iodoform** - Matches with **Antiseptic** (ii) 2. **Methyl salicylate** - Matches with **Pain balm** (v) 3. **Diethyl ether** - Matches with **Anaesthetic** (i) 4. **Hexachlorocyclohexane** - Matches with **Insecticide** (iii)

Step 4: Compile the Matches

List the final pairings: 1. Iodoform - Antiseptic (ii) 2. Methyl salicylate - Pain balm (v) 3. Diethyl ether - Anaesthetic (i) 4. Hexachlorocyclohexane - Insecticide (iii)

Key Concepts

Iodoform

Iodoform is a compound known for its distinct yellow crystalline appearance and strong medicinal odor. Historically, it was widely used for its antiseptic properties. It can effectively kill or inhibit the growth of bacteria and other pathogens on the skin, making it ideal for treating wounds. While modern antiseptics have reduced its prevalence in the medical field, iodoform's legacy as a disinfectant remains notable. Its application was mostly external, primarily used to clean minor cuts and abrasions.

Methyl Salicylate

Methyl salicylate is a chemical widely recognized for its role in topical pain relief. Derived from wintergreen oil, it acts as a counterirritant, which means it provides minor irritation to the skin to distract from deeper pain. You might find it in over-the-counter balms and creams designed to relieve muscle and joint pain. When applied onto the skin, it can produce a warming sensation that enhances blood circulation and provides relief. Its pleasant scent is often used in flavoring and fragrances.

Diethyl Ether

Diethyl ether is an organic compound known primarily for its role as an anesthetic. Historically, it was used in surgeries to induce unconsciousness. It acts rapidly, allowing patients to feel no sensation, making it revolutionary in the medical field. However, due to its high flammability and potential side effects, its medical use has declined, replaced by safer alternatives. Nonetheless, diethyl ether's contribution to anesthesia played a significant role in advancing surgical procedures.

Hexachlorocyclohexane

Hexachlorocyclohexane, also known as Lindane, is a chemical historically used as an insecticide. It targets a wide range of insects, making it effective in agricultural settings to protect crops. Hexachlorocyclohexane works by messing with the nervous system of insects, leading to their eventual death. However, due to environmental and health concerns associated with its use, many countries have regulated or phased out its application. It serves as a reminder of the importance of balancing the effectiveness of chemicals with safety and environmental protection.