Soda production. Calcium and magnesium
Answers are for parents and teachers.
1
Write equations for the chain Ca → CaO → Ca(OH)₂ → CaCO₃.
2Ca + O₂ → 2CaO; CaO + H₂O → Ca(OH)₂; Ca(OH)₂ + CO₂ → CaCO₃↓ + H₂O.
2
How many grams of Ca(OH)₂ form when 56 g CaO reacts with water? (M(Ca(OH)₂) = 74)
74
3
How many moles of Na₂CO₃ are in 1144 g of crystalline soda? (M = 286 g/mol)
4
4
Burning magnesium cannot be put out with water. Why? (chemical reason only)
Hot Mg reacts even with water giving hydrogen (Mg + H₂O → MgO + H₂), which burns.
5
Write two sentences about the roles of calcium and magnesium in humans and plants.
Calcium phosphate forms bones and teeth; magnesium is part of chlorophyll and is needed for photosynthesis.