Problem 15 - A Complete Resource Book in Chemistry for JEE Main

Question

Antidote of Lewsite is (a) 3, 3 -dimercaptopropan-1-ol (b) 2 -mercaptopropan-1, 3 -diol (c) 2,3 -dimercaptopropan-1-ol (d) 2,2 -dimercaptopropan-1-ol

Step-by-Step Solution

Answer

The antidote for Lewisite is 2,3-dimercaptopropan-1-ol, which is option (c).

Step 1: Understanding the Problem

We need to find the correct chemical antidote for Lewisite, which is a chemical warfare agent.

Step 2: Identify the Known Antidote

The known antidote for Lewisite is British Anti-Lewisite, also known as Dimercaprol.

Step 3: Matching Chemical Structure

Dimercaprol's chemical name is 2,3-dimercaptopropanol. We need to find the option that matches this structure.

Step 4: Analyze the Options

Option (a), 3,3-dimercaptopropan-1-ol, does not match since the mercapto groups are on the third carbon. Option (b), 2-mercaptopropan-1,3-diol, only has one mercapto group. Option (c), 2,3-dimercaptopropan-1-ol, matches exactly with Dimercaprol. Option (d), 2,2-dimercaptopropan-1-ol, would have both mercapto groups on the second carbon.

Step 5: Selecting the Answer

Based on the analysis, option (c) is the correct match for the chemical structure of Dimercaprol, the antidote for Lewisite.

Key Concepts

Dimercaprol

Dimercaprol is a crucial compound in the field of medicine, especially for counteracting toxic substances like Lewisite. Originally developed during World War II, it serves as an effective antidote against poisoning by certain arsenic-containing chemical warfare agents. The chemical structure of Dimercaprol is 2,3-dimercaptopropanol, which indicates the presence of two mercapto (thiol or sulfur-containing) groups on carbons 2 and 3 of the propane backbone.

Here's why Dimercaprol is effective:

• It acts as a chelating agent, meaning it binds to metals and potentially harmful substances in the body, forming a complex that can be safely excreted.
• Its thiol groups are critical for binding, as sulfur has a high affinity for metals.
• This process reduces the toxicity of arsenic compounds and aids in their removal from the bloodstream.

Dimercaprol is not only used for Lewisite but also for treating cases of mercury, gold, and other heavy metal poisonings. It showcases the importance of chemical structure in the function of medicinal drugs.

Chemical Warfare Agent

Chemical warfare agents like Lewisite are substances designed to harm or kill through toxic properties. These were infamously used in warfare to incapacitate and harm soldiers and civilians alike. Understanding these agents is critical, not just for defense purposes but also for emergency medical treatment.

Lewisite is one such agent, an organoarsenic compound, known for its blistering effects on the skin and mucous membranes. Fortunately, with the correct use of antidotes like Dimercaprol, the harmful effects can be countered effectively. The need for quick identification and treatment in cases of exposure underscores the necessity for extensive knowledge and preparedness regarding chemical warfare agents.

Organic Chemistry Nomenclature

Mastering organic chemistry nomenclature is crucial for understanding the structure and function of complex molecules like Dimercaprol. This system allows chemists to convey the specific arrangement of atoms in a compound through its name. Let's break down what you might see in nomenclature like 2,3-dimercaptopropan-1-ol.

• The numbers (e.g., 2,3) specify the positions of substituents or functional groups on the carbon chain.
• 'Mercapto' refers to the presence of a thiol group, containing sulfur.
• 'Propane' indicates a three-carbon backbone.
• '-ol' at the end of the name signifies an alcohol group is present.

Being familiar with these naming conventions helps in predicting and understanding the chemical's behavior and reactivity. This systematic approach is vital for students and professionals dealing with organic molecules in various scientific fields.