Problem 44 - A Complete Resource Book in Chemistry for JEE Main

Question

The \(\mathrm{Na}^{+}\)present in \(\mathrm{NaCl}\) is (a) acidic radical (b) basic radical (c) neutral radical (d) none of these

Step-by-Step Solution

Answer

The Na⁺ from NaCl is a basic radical.

Step 1: Define Radicals

In chemistry, a radical is an atom, molecule, or ion that has an unpaired valence electron. In the context of acids and bases, radicals can be classified based on whether they form acidic or basic solutions in water.

Step 2: Analyze NaCl Composition

NaCl, also known as sodium chloride, is composed of two ions: Na⁺ (sodium ion) and Cl⁻ (chloride ion). When NaCl is dissolved in water, it dissociates into these ions.

Step 3: Determine the Nature of Na⁺ Ion

The Na⁺ ion (sodium ion) is a metal cation. Metal cations typically come from bases, especially from hydroxides like NaOH (sodium hydroxide), which is a base. Thus, the presence of Na⁺ in solution would generally indicate a basic radical.

Step 4: Finalize Classification of Na⁺ Ion

Given the characteristic of Na⁺ as a metal cation from a base (NaOH), it is classified as a basic radical. It is not acidic or neutral.

Key Concepts

Radicals in Chemistry

In chemistry, radicals can at first seem a bit confusing, but they are an important concept to grasp. A radical is essentially an atom, molecule, or ion that contains an unpaired valence electron. This unpaired electron means that radicals are often highly reactive. However, it's important to clarify that radicals in terms of ions like \(abla^+\) refer more to their behavior in forming acidic or basic solutions, rather than having unpaired electrons. Radicals are often mentioned in the context of organic chemistry but can be just as relevant in inorganic contexts, such as when discussing ions. Learning to identify radicals can help students understand more complex chemical reactions.

Sodium Chloride Dissociation

When sodium chloride, commonly known as table salt, dissolves in water, it undergoes a process called dissociation. Dissociation is the act of breaking down a compound into its constituent ions. In the case of NaCl, it dissociates into sodium ions \(\mathrm{Na^{+}}\) and chloride ions \(\mathrm{Cl^{-}}\). This process is crucial because it allows for the free movement of ions in the solution, which leads to the conductivity of the solution.
Understanding the dissociation of ionic compounds like sodium chloride is fundamental, as it lays the groundwork for studying more complex solutions and reactions.

Cation Behavior in Solutions

Cations, positively charged ions, behave interestingly when in solution. For example, the sodium ion \(\mathrm{Na^{+}}\) is a cation that originates from sodium chloride. When sodium chloride is dissolved in water, the \(\mathrm{Na^{+}}\) ions separate from the \(\mathrm{Cl^{-}}\) ions. This free movement contributes to the solution's overall conductivity.
Metal cations like \(\mathrm{Na^{+}}\) are typically derived from basic substances such as sodium hydroxide (NaOH). This means they are usually associated with basic radicals. This behavior is essential for understanding how different ions influence the pH of solutions and the general chemistry of cations.