See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Analysis of Isomerism in $CH_3CH(OH)COOH$ **Step 1: Identify the structure** $CH_3CH(OH)COOH$ is lactic acid with a chiral center at the carbon bearing the $-OH$ group. **Step 2: Check for geometric isomerism** Geometric isomerism requires a $C=C$ or $C=N$ double bond with restricted rotation. This molecule has only single bonds, so **no geometric isomerism** exists. **Step 3: Check for optical isomerism** The central carbon atom ($CH(OH)$) has four different groups attached: - $-CH_3$ - $-OH$ - $-COOH$ - $-H$ Since all four substituents are different, this carbon is a **chiral center**, producing two non-superimposable mirror images (D- and L-forms). **Step 4: Conclusion** The molecule exhibits **optical isomerism only**, not geometric isomerism. **Answer: (2) Optical isomerism** ✓