Alkenes combine with carbon monoxide and hydrogen in presence of octacarbonyldicobalt as catalyst un — Hydrocarbons Chemistry Question

💡 Solution & Explanation

# Hydroformylation Reaction **The reaction described is the hydroformylation (or oxo synthesis):** $$\text{Alkene} + \text{CO} + \text{H}_2 \xrightarrow[\text{high P, T}]{\text{Co}_2(\text{CO})_8} \text{Aldehyde}$$ **Step-by-step reasoning:** 1. **Reactants identified:** Alkene ($C=C$) + CO + $H_2$ with octacarbonyldicobalt [$\text{Co}_2(\text{CO})_8$] catalyst 2. **Mechanism:** The cobalt catalyst activates CO and $H_2$, forming a metal-hydridocarbonyl intermediate that inserts the alkene into the C-H bond. 3. **Product formed:** The process adds a formyl group (–CHO) to the alkene, producing an **aldehyde** as the primary product. 4. **Example:** $$\text{CH}_2=\text{CH-CH}_3 + \text{CO} + \text{H}_2 \rightarrow \text{CH}_3\text{-CH}_2\text{-CHO}$$ (propene → butanal) 5. **Why this reaction?** This is a classic industrial process (Ruhrchemie/Rhône-Poulenc process) used to convert alkenes to aldehydes, which are valuable intermediates. **Answer A is correct: Aldehydes are formed** through this well-established carbonylation pathway.