Two moles of acetic acid are heated with , The product formed is — Aldehydes Ketones and Carboxylic Acids Chemistry Question

💡 Solution & Explanation

# Solution: Reaction of Acetic Acid with $P_2O_5$ **Step 1: Identify the reactant and reagent** - Reactant: 2 moles of acetic acid ($CH_3COOH$) - Reagent: $P_2O_5$ (phosphorus pentoxide) — a strong dehydrating agent **Step 2: Recognize the reaction type** $P_2O_5$ is a powerful dehydrating agent that removes water from organic compounds. When applied to carboxylic acids, it causes **dehydration of two carboxylic acid molecules**. **Step 3: Write the condensation reaction** Two molecules of acetic acid condense with loss of one water molecule: $$2 \, CH_3COOH \xrightarrow{P_2O_5} CH_3-CO-O-CO-CH_3 + H_2O$$ **Step 4: Identify the product** The product is **acetic anhydride** ($CH_3CO)_2O$ or $(CH_3CO)_2O$) The two acyl groups ($CH_3CO-$) combine through an oxygen atom, forming a symmetrical anhydride. **Why this is correct:** Acetic anhydride is the characteristic product when acetic acid reacts with $P_2O_5$. The dehydrating agent facilitates the condensation of two carboxylic acid molecules into their anhydride, removing one water molecule in the process.