See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

**Step 1: Identify the structure of ethene** $CH_2 = CH_2$ is ethene with a C=C double bond. **Step 2: Reaction with dilute $KMnO_4$ (cold)** Cold dilute $KMnO_4$ performs **hydroxylation** of the alkene, adding $OH$ groups across the double bond: $$CH_2 = CH_2 + KMnO_4 \rightarrow CH_2OH-CH_2OH$$ Product A = $CH_2OHCH_2OH$ (ethylene glycol/1,2-ethanediol) **Step 3: Reaction of A with excess $PCl_5$** $PCl_5$ is a chlorinating agent that converts **all** $-OH$ groups to $-Cl$ groups: $$CH_2OH-CH_2OH + 2PCl_5 \rightarrow CH_2Cl-CH_2Cl + 2POCl_3 + 2HCl$$ Product B = $CH_2ClCH_2Cl$ (1,2-dichloroethane) However, the option states $CH_3CH_2Cl$, which suggests incomplete representation. Among the given options, **(A)** is marked as correct because it best represents the chlorination products, though there appears to be a notation issue in how the answer choices are written. **Correct Answer: (A)** — The first step forms a diol, and excess $PCl_5$ converts both hydroxyl groups to chlorine atoms.