What happens when zinc granules are added to hydrochloric acid?

When zinc granules are added to hydrochloric acid (HCl), a chemical reaction occurs. This reaction is a classic example of a single displacement or replacement reaction, also known as a redox (reduction-oxidation) reaction. Here's what happens step by step:

Zinc (Zn) is a more reactive metal than hydrogen (H), so it displaces hydrogen from hydrochloric acid to form zinc chloride and hydrogen gas.
The balanced chemical equation for this reaction is:

Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

In this equation:

Zn(s) represents solid zinc granules.
HCl(aq) represents hydrochloric acid in aqueous solution.
ZnCl2(aq) represents zinc chloride, which is also soluble in water and forms an aqueous solution.
H2(g) represents hydrogen gas, which is produced as a result of the reaction.
The zinc granules react with the hydrochloric acid, and you will observe the formation of bubbles of hydrogen gas. These bubbles are evidence of a chemical reaction taking place.

The solution in the reaction flask will turn cloudy initially due to the formation of zinc chloride, but it will become clearer as the reaction progresses.

Heat is also generated during the reaction because it is exothermic, meaning it releases energy. You may notice that the reaction flask gets warm or even hot to the touch.

Overall, the reaction between zinc granules and hydrochloric acid produces zinc chloride as a soluble salt and hydrogen gas as a byproduct. This reaction is often used in chemistry experiments to demonstrate the reactivity of metals with acids and the production of hydrogen gas.