Translate the following statements into chemical equations and then balance them.
Hydrogen gas combines with nitrogen to form ammonia.
(a) Hydrogen gas combines with nitrogen to form ammonia. Unbalanced equation: H₂ + N₂ → NH₃ Balanced equation: 3H₂ + N₂ → 2NH₃
Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
(b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide. Unbalanced equation: H₂S + O₂ → H₂O + SO₂ Balanced equation: 2H₂S + 3O₂ → 2H₂O + 2SO₂
Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate. Unbalanced equation: BaCl₂ + Al₂(SO₄)₃ → AlCl₃ + BaSO₄ Balanced equation: 3BaCl₂ + Al₂(SO₄)₃ → 2AlCl₃ + 3BaSO₄
Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas. Unbalanced equation: K + H₂O → KOH + H₂ Balanced equation: 2K + 2H₂O → 2KOH + H₂
Explanation
The question asks students to translate word statements into chemical equations and balance them. According to the law of conservation of mass mentioned in the context, the number of atoms of each element must remain the same before and after a chemical reaction. Each equation has been balanced by adjusting coefficients to ensure equal numbers of atoms on both sides.