Question

What happens when dilute sulfuric acid is poured on zinc granules?

Answer 1

When dilute sulfuric acid is added to the zinc granules then a displacement reaction occurs. The displacement reaction is a reaction where a more reactive element displaces a less reactive element in its aqueous salt solution. The reactivity of elements (metals) is identified through a reactivity series where the elements above, displace the elements below, and hydrogen comes in between this series as a reference.

Complete answer:
Dilute sulfuric acid is an acidic compound with chemical formula${{H}_{2}}S{{O}_{4}}$. When it is added to zinc granules we can observe a displacement reaction. This reaction results in the displacement of hydrogen by the zinc metal. The reaction is as follows:
${{H}_{2}}S{{O}_{4}}(aq)+Zn(s)\to ZnS{{O}_{4}}(aq)+{{H}_{2}}(g)\uparrow$
The reaction produces zinc sulfate and hydrogen gas as products. Zinc displaces hydrogen from its aqueous solution as zinc is just above hydrogen in the reactivity series, means it is more reactive than hydrogen so displaces it in aqueous solution. The hydrogen gas evolved can be detected by keeping a matchstick near the test tube that will burn with a pop sound.
Hence, when dilute sulfuric acid is poured on zinc granules then zinc displaces the hydrogen from sulfuric acid to form zinc sulfate and hydrogen gas as products.

Note:
The reactivity series tells us the reactivity of metals in decreasing order. According to this series, some of the metals that are more active than hydrogen are sodium, potassium, lithium, iron, chromium, nickel, tin, lead and zinc. These metals are above hydrogen in the activity series. While the noble metals like gold, silver, platinum are at the end being less reactive.