A 100 mL solution of CH CH MgBr on treatment with methanol produces 2.24 mL of a gas at STP. The wei — Hydrocarbons Chemistry Question

💡 Solution & Explanation

**Step 1: Write the reaction equation** CH₃CH₂MgBr + CH₃OH → CH₃CH₃ + CH₃OMgBr The Grignard reagent reacts with methanol to produce ethane gas. **Step 2: Calculate moles of gas produced** Using the molar volume at STP: 1 mole of gas = 22.4 L = 22,400 mL Moles of ethane = 2.24 mL ÷ 22,400 mL/mol = 0.0001 mol = 1 × 10⁻⁴ mol **Step 3: Calculate molar mass of ethane (C₂H₆)** Molar mass = (2 × 12) + (6 × 1) = 24 + 6 = 30 g/mol **Step 4: Calculate mass of gas produced** Mass = moles × molar mass Mass = 1 × 10⁻⁴ mol × 30 g/mol = 3 × 10⁻³ g **Step 5: Convert to milligrams** Mass = 3 × 10⁻³ g × 1000 mg/g = 3 mg Therefore, the answer is 3.00.