See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Finding Isomers of $C_2H_2Br_2$ **Step 1: Determine the structure** With 2 carbons, 2 hydrogens, and 2 bromines, we have a dibromoethene or dibromethane compound. The degree of unsaturation = 1, indicating either a double bond or a ring. **Step 2: Identify possible structures** For $C_2H_2Br_2$, the most likely structures are: 1. **Geminal dibromide (1,1-dibromethene):** $CHBr=CHBr$ with both bromines on the same carbon - Structure: $\text{Br}_2C=CH_2$ (no isomerism) 2. **Vicinal dibromide (1,2-dibromethene):** $CHBr=CHBr$ with bromines on different carbons - **cis-isomer:** Both $Br$ atoms on same side of double bond - **trans-isomer:** $Br$ atoms on opposite sides of double bond **Step 3: Count geometric isomers** The $CHBr=CHBr$ structure exhibits **geometric (cis-trans) isomerism** because: - The double bond prevents rotation - Two different substituents (H and Br) exist on each carbon This gives **2 distinct isomers**: cis and trans configurations. **Answer: (B) 2** The two isomers are **(Z)-1,2-dibromethene** and **(E)-1,2-dibromethene**, which are geometric isomers of each other.