Calcium carbide on hydrolysis forms — Hydrocarbons Chemistry Question

💡 Solution & Explanation

# Hydrolysis of Calcium Carbide **Step 1: Identify the reactant structure** Calcium carbide is $CaC_2$, where the carbide ion is $C_2^{2-}$ (acetylide ion with a triple bond: $C \equiv C$) **Step 2: Write the hydrolysis reaction** $$CaC_2 + 2H_2O \rightarrow Ca(OH)_2 + C_2H_2$$ **Step 3: Identify the product** The organic product formed is $C_2H_2$ (acetylene or ethyne), a colorless gas with the structure $HC \equiv CH$ **Step 4: Physical properties of the products** - **$Ca(OH)_2$**: White precipitate (calcium hydroxide) - **$C_2H_2$**: Colorless, flammable gas with a characteristic pungent odor - The gas is combustible and burns with a bright, sooty flame **Answer: Calcium carbide hydrolyzes to form calcium hydroxide [white precipitate] and acetylene gas [$C_2H_2$], a colorless, combustible gas.** This reaction is historically important and was used as a source of acetylene for lighting before electric bulbs became common.