Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid (HCL) is added to test tube A, while acetic acid (CH₃COOH) is added to test tube B. Amount and concentration taken for both the acids are same. In which test tube will the fizzing occur more vigorously and why?

Fizzing occurs only when gas is formed as a product in the chemical reaction.

Test Tube A: When magnesium ribbon is added to hydrochloric acid (strong acid), magnesium chloride and hydrogen (due to which the fizz is observed) are formed.

$Mg (s) + HCl (aq) \ rightarrow MgCl_2 (aq) + H_2 (g)$

Test Tube B: When magnesium reacts with acetic acid (weak acid), it produces hydrogen gas due to which the fizz is observed.

$Mg (s) + CH_3COOH (aq) \ rightarrow Mg(CH_3COO)2 (aq) + H_2 (g)$

Hence, fizz is observed in both cases, Hydrogen gas is produced. But as HCl is a strong acid, hence, the fizz observed will be more in test tube A.