Which of the following compounds can for...

Which of the following compounds can form a Zwitter ion ?

Benzoic acid

Acetanilide

Aniline

Glycine

Text Solution

AI Generated Solution

The correct Answer is:

To determine which of the given compounds can form a zwitterion, we need to understand what a zwitterion is. A zwitterion is a molecule that has both positive and negative charges but is overall electrically neutral. This typically occurs in amino acids at their isoelectric point, where the amino group is protonated (NH3+) and the carboxyl group is deprotonated (COO-). Let's analyze each option step by step: ### Step 1: Analyze Benzoic Acid - **Structure**: Benzoic acid has the formula C6H5COOH. - **Functional Groups**: It contains a carboxylic acid group (-COOH). - **Charge Formation**: At neutral pH, benzoic acid can lose a proton from the carboxylic acid group, forming the benzoate ion (C6H5COO-), but it does not have a basic amine group to gain a proton and form a positive charge. - **Conclusion**: Benzoic acid cannot form a zwitterion. ### Step 2: Analyze Acetanilide - **Structure**: Acetanilide has the formula C6H5NH(CO)CH3. - **Functional Groups**: It contains an amide group and a benzene ring. - **Charge Formation**: There is no carboxylic acid group to lose a proton, and the nitrogen does not have a proton to donate to form a positive charge. - **Conclusion**: Acetanilide cannot form a zwitterion. ### Step 3: Analyze Aniline - **Structure**: Aniline has the formula C6H5NH2. - **Functional Groups**: It contains an amine group (-NH2) attached to a benzene ring. - **Charge Formation**: Aniline can accept a proton to become anilinium (C6H5NH3+), but it does not have a carboxylic acid group to lose a proton and form a negative charge. - **Conclusion**: Aniline cannot form a zwitterion. ### Step 4: Analyze Glycine - **Structure**: Glycine has the formula NH2CH2COOH. - **Functional Groups**: It contains both an amino group (-NH2) and a carboxylic acid group (-COOH). - **Charge Formation**: At the isoelectric point, glycine can exist as NH3+ (protonated amine) and COO- (deprotonated carboxylic acid), resulting in a zwitterion. - **Conclusion**: Glycine can form a zwitterion. ### Final Answer The compound that can form a zwitterion is **D) Glycine**.