See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

## Identifying Functional Isomers of Monocarboxylic Acids **Step 1: Define monocarboxylic acids** Monocarboxylic acids have the general formula $C_nH_{2n}O_2$ with one $-COOH$ group. **Step 2: Determine what functional isomers must have** Functional isomers have: - Same molecular formula - Different functional groups - Different chemical properties **Step 3: Compare molecular formulas** - Monocarboxylic acid: $-COOH$ contains $C_1O_2H_1$ - **Esters** have formula $-COOR$ (one C, two O, one H in the acid part) - Example: $CH_3COOH$ (acetic acid, $C_2H_4O_2$) and $HCOOCH_3$ (methyl formate, $C_2H_4O_2$) **Step 4: Check other options** - **(A) Ethers**: $R-O-R'$ contain only one oxygen → cannot match $C_nH_{2n}O_2$ ✗ - **(B) Amines**: $R-NH_2$ contain nitrogen → different molecular formula ✗ - **(D) Alcohols**: Would need multiple $-OH$ groups to match formula; also don't represent the same family ✗ **Answer: (C) Esters** Monocarboxylic acids and esters share the same molecular formula but differ in functional groups ($-COOH$ vs $-COOR$), making them functional isomers.