Science (086) — AI-generated practice question

When zinc granules are added to dilute sulphuric acid, the following observations indicate a chemical reaction has taken place:

1. Bubbles of gas (hydrogen) are evolved on the surface of the zinc granules.
2. The zinc granules gradually dissolve (decrease in size), showing that a new substance, zinc sulphate, is being formed.

$$\text{Zn}(s) + \text{H}_2\text{SO}_4(aq) \rightarrow \text{ZnSO}_4(aq) + \text{H}_2(g)$$

Source: Chapter 1, Section 1.1.2

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The examiner expects two distinct, observable signs of a chemical reaction — not just the equation. The two most commonly accepted answers are: (1) evolution of hydrogen gas (bubbles) and (2) dissolution/disappearance of zinc granules. A third valid option is that the reaction mixture may become warm (heat is released), indicating an exothermic reaction. Always name the gas produced for full marks. Writing the equation is a bonus but is not mandatory for a 2-mark very short answer.