Question

Statement-1 : \(\mathrm{Cr}^{* 3}\) is a reducing agent and \(\mathrm{Mn}^{+2}\) is oxidising agent. Statement-2: \(\mathrm{Mn}^{+3}\) has \(\mathrm{d}^{5}\) configuration. (1) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1. (2) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1. (3) Statement- 1 is True, Statement-2 is False. (4) Statement-1 is False, Statement-2 is True.

Short answer

Option (3): Statement-1 is True, Statement-2 is False.

Step-by-step solution

Examine Statement-1

Determine if \(\text{Cr}^{3+}\) is a reducing agent and \(\text{Mn}^{2+}\) is an oxidizing agent. A reducing agent loses electrons (is oxidized) and an oxidizing agent gains electrons (is reduced). \(\text{Cr}^{3+}\) can act as a reducing agent as it can further lose electrons to form \(\text{Cr}^{6+}\) or \text{Cr}^{0}\. So, Statement-1 is potentially true.

Examine Statement-2

Determine the electronic configuration of \(\text{Mn}^{3+}\). Manganese (Mn) atomic number is 25, so its ground state configuration is \([Ar] 3d^5 4s^2\). When Mn is in the \(\text{Mn}^{2+}\) state, it loses 2 electrons to become \([Ar] 3d^5\). In the \(\text{Mn}^{3+}\) state, it loses another electron to become \([Ar] 3d^4\). Therefore, Statement-2 is false because \(\text{Mn}^{3+}\) has a \(\text{3d}^4\) configuration, not \text{d}^{5}\text.

Verify Explanation

Since Statement-2 is false, it cannot explain Statement-1. Therefore, we do not need to check the logical relationship between Statement-1 and Statement-2.

Conclusion

Given the analysis, Statement-1 is true, and Statement-2 is false. This matches option (3).

Key concepts

Understanding Oxidizing and Reducing Agents

In redox chemistry, an oxidizing agent is a substance that gains electrons and, in the process, gets reduced. On the other hand, a reducing agent is a substance that loses electrons and becomes oxidized. It's all about the transfer of electrons.
For example, in the solution given, \(\text{Cr}^{3+}\) is called a reducing agent because it can lose electrons and thus get oxidized further, leading to a higher oxidation state such as \(\text{Cr}^{6+}\). Similarly, \(\text{Mn}^{2+}\) is called an oxidizing agent because it can gain electrons and get reduced, potentially to a lower oxidation state.

The Basics of Electronic Configuration

Electronic configuration refers to the arrangement of electrons in an atom or ion. This arrangement follows the principles of quantum mechanics and provides crucial insights into the chemical behavior of an element.
For instance, manganese (\text{Mn}) has an atomic number of 25, which means it has 25 electrons in a neutral atom. The ground state electronic configuration is \([Ar] 3d^5 4s^2\). When \text{Mn} becomes \text{Mn}^{2+}\, it loses two electrons, resulting in the configuration \([Ar] 3d^5\). If it further loses another electron to form \text{Mn}^{3+}\, the configuration changes to \([Ar] 3d^4\). Understanding these configurations can help explain reactivity and bonding properties of elements and their ions.

Characteristics of Transition Metal Ions

Transition metals are unique because they have partially filled d-orbitals. This gives them fascinating properties such as variable oxidation states, the ability to form colored compounds, and participation in redox reactions.
For example, examining transition metal ions like \(\text{Cr}^{3+}\) and \(\text{Mn}^{3+}\) reveals significant insights into their chemical behavior. \(\text{Cr}^{3+}\) is in a stable oxidation state but can still act as a reducing agent under certain conditions, while \(\text{Mn}^{3+}\) has a somewhat less stable configuration (\text{3d}^4). These properties are crucial for understanding their role in various chemical reactions, especially in redox processes.
Moreover, the d-orbitals can accept and donate electrons, making these ions very versatile and useful in catalysis and industrial applications.