Final answer:
The balanced molecular equations are provided for the decomposition of calcium carbonate, the reaction of butane with oxygen, magnesium chloride with sodium hydroxide, and the reaction of water vapor with sodium metal.
Step-by-step explanation:
Writing balanced molecular equations involves ensuring that the same number of each type of atom appears on both sides of the equation, in accordance with the law of conservation of mass. Below are the balanced equations for the provided reactions:
- a) Solid calcium carbonate decomposes into solid calcium oxide and carbon dioxide gas: CaCO₃ (s) → CaO (s) + CO₂ (g)
- b) Gaseous butane reacts with diatomic oxygen gas to produce carbon dioxide and water vapor: 2C₄H₁₀ (g) + 13O₂ (g) → 8CO₂ (g) + 10H₂O (g)
- c) Magnesium chloride reacts with sodium hydroxide to produce magnesium hydroxide and sodium chloride: MgCl₂ (aq) + 2NaOH (aq) → Mg(OH)₂ (s) + 2NaCl (aq)
- d) Water vapor reacts with sodium metal to produce sodium hydroxide and hydrogen gas: 2Na (s) + 2H₂O (g) → 2NaOH (s) + H₂ (g)
These balanced equations allow us to accurately represent chemical reactions.