Balance the following equation and add state symbols:

Zn + HCl ZnCl₂ + H₂

21 Potassium metal reacts with water to give potassium hydroxide and hydrogen gas. Write a ba lanced chemical equation for this reaction. 22 Explain, with example, how the physical states of the reactants and products can be shown in a chemical equation. 22 Convey the following information in the form of a balanced chemical equation:

"An aqueous solution of ferrous sulphate reacts with an aqueous solution of sodium hydroxide to form a precipitate of ferrous hydroxide and sodium sulphate remains in solution."

23 Write any two observations in an activity which may suggest that a chemical reaction has taken place. Give an example in support of your answer.