Equal lengths of magnesium ribbons are taken in test tubes \(\mathrm{A}\) and \(\mathrm{B}\). Hydrochloric acid \((\mathrm{HCl})\) is added to test tube \(\mathrm{A}\), while acetic acid \(\left(\mathrm{CH}_{3} \mathrm{COOH}\right)\) 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?

Acids are substances that can donate protons (hydrogen ions, \( \text{H}^+ \)) when dissolved in water. The strength of an acid depends on its ability to ionize in solution.

• Strong Acids: Strong acids, like hydrochloric acid \( \text{HCl} \), ionize completely in water. This means that almost every acid molecule donates a proton, releasing a large number of hydrogen ions into the solution.
• Weak Acids: Weak acids, like acetic acid \( \text{CH}_3\text{COOH} \), do not fully ionize in water. Instead, only a small fraction of the molecules release protons. As a result, the concentration of hydrogen ions is much lower compared to strong acids.

In the given exercise, test tube A contains a strong acid \( \text{HCl} \), while test tube B contains a weak acid \( \text{CH}_3\text{COOH} \). Even though both acids are in the same concentration, hydrochloric acid will produce more hydrogen ions, leading to a stronger reaction.

Ionization refers to the process by which an acid releases hydrogen ions \( \text{H}^+ \) into the water.

• Complete Ionization: Strong acids like \( \text{HCl} \) undergo complete ionization. This means that they dissociate entirely into their constituent ions when mixed with water. For example, \( \text{HCl} \) will separate completely into \( \text{H}^+ \) and \( \text{Cl}^- \) ions.
• Partial Ionization: Weak acids like \( \text{CH}_3\text{COOH} \) only partially ionize in water. A large portion of the acid molecules remain undissociated. For instance, in water, acetic acid will primarily remain as \( \text{CH}_3\text{COOH} \) with only a small amount dissociating into \( \text{CH}_3\text{COO}^- \) and \( \text{H}^+ \) ions.

This difference in ionization impacts the rate and vigor of chemical reactions. In the exercise, the greater ionization of \( \text{HCl} \) leads to more hydrogen ions being available for reaction with magnesium, which in turn results in more vigorous fizzing.

When acids react with metals like magnesium, one of the products is hydrogen gas \( \text{H}_2 \). The overall reaction can be summarized as follows: \[ \text{Acid} + \text{Metal} \rightarrow \text{Salt} + \text{Hydrogen gas} \]
For example, when magnesium reacts with hydrochloric acid, the chemical reaction is: \[ \text{Mg} + 2 \text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2 \]
Similarly, with acetic acid the reaction is: \[ \text{Mg} + 2 \text{CH}_3\text{COOH} \rightarrow \text{(CH}_3\text{COO)}_2\text{Mg} + \text{H}_2 \] Since hydrochloric acid (a strong acid) ionizes more completely, it provides more hydrogen ions for the reaction. Thus, more hydrogen gas \( \text{H}_2 \) will be produced when magnesium is added to \( \text{HCl} \) compared to \( \text{CH}_3\text{COOH} \). This results in the more vigorous fizzing observed in test tube A.