Question

Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid $$\left(HCl\right)$$ is added to test-tube A, while acetic acid $$\left(C{H}_{3}COOH\right)$$ is added to test tube B. In which test tube will have fizzing occur more vigorously?
A. A
B. B
C. Both
D. None

Answer 1

Hint: As we know that fizzing occurs in a chemical reaction due to the presence of a gas. Here, to identify the test tube in which fizzing occurs more vigorously, then we need to compare the acidity of both $$C{H}_{3}COOH$$ and $$HCl$$.

Complete step by step answer:
According to question when equal lengths of magnesium ribbons are taken in test tubes A and B. Then, hydrochloric acid $$\left(HCl\right)$$ is added to test-tube A, while acetic acid $$\left(C{H}_{3}COOH\right)$$ is added to test tube B.
Thus, the reaction in test tube A is:
$Mg(s)+2HCl(aq)\to MgC{l}_2(aq)+H_2(g)$
And the reaction in test tube B is:
$Mg(s)+C{H}_{3}COOH(aq)\to Mg(C{H}_{3}COO{)}_2(aq)+H_2(g)$
It is evident that hydrogen gas is released in both the reactions. Though concentration of both the acids is same but we also know that hydrochloric acid is a stronger and reactive acid than acetic acid and therefore, the hydrogen gas produced in the reaction is at a faster rate due to which frizzing occurs in test tube A. ​
As $$HCl$$ is a stronger acid as compared to$C{H}_{3}COOH$, magnesium metal is added to the chemical reaction. Thus, $$HCl$$ produces hydrogen gas due to which fizzing will be more vigorous in test-tube A.

So, the correct answer is Option A .

Note:
From the above question, we get to know that fizzing will occur more in test tube A because:
$$HCl$$ is a stronger acid whereas $C{H}_{3}COOH$ is a weaker acid.
Hydrochloric acid completely dissociates into $H^{+}$ and $C{l}^{-}$ions while $C{H}_{3}COOH$doesn’t ionize completely.