If the mass of a mixture of carbonate and hydroxide of a divalent metal with a molar ratio of 2:3 decreases by 28.28% when heated, identify the unknown metal.
- Mg
- Fe
- Cu
- Al
📝 Detailed explanation
MCO₃ → MO + CO₂M(OH)₂ → MO + H₂O
Mass loss = (2 × 44 + 3 × 18) / (2 × (M + 60) + 3 × (M + 34)) = 0.2828.
142 / (5M + 222) = 0.2828.
5M + 222 = 502.
5M = 280, M = 56.
Metal is Iron (Fe).
Correction: Calculation with Cu (64) gives different percentage.
Checking for Fe: 142 / (5*56 + 222) = 142 / 502 = 0.2828.
Metal is Iron.