When a manganous salt is fused with a mixture of \(\mathrm{KNO}_{3}\) and solid \(\mathrm{NaOH}\) the oxidation number of \(\mathrm{Mn}\) changes from \(+2\) to (a) \(+4\) (b) \(+3\) (c) \(+6\) (d) \(+7\)

Oxidation is a fundamental concept in chemistry, particularly when discussing the changes in manganous salts. Manganous salts contain manganese in a +2 oxidation state, which can be altered under certain chemical reactions. The oxidation of manganous salts typically involves the increase in oxidation number of manganese due to the loss of electrons.

For example, during the fusion of a manganous salt with a mixture of potassium nitrate ((KNO_3)) and solid sodium hydroxide ((NaOH)), a potent oxidizing environment is created. This shifts the oxidation number of manganese from +2 to a higher number. It's important to remember that the increase in oxidation state is indicative of an oxidation reaction, where electrons are being removed from the manganese ion. The actual outcome—whether manganese ends up in a +6 or +7 oxidation state—depends on the conditions and the strength of the oxidizing agents involved.

Oxidizing agents are substances that have the ability to oxidize other substances by accepting electrons from them. In the context of chemical oxidation-reduction (redox) reactions, the oxidizing agent facilitates the gain of oxygen or loss of hydrogen of another substance, while itself being reduced in the process. A common oxidizing agent is potassium nitrate ((KNO_3)), which contains the nitrate ion ((NO_3^-)) known for its oxidizing power.

In our specific case with manganous salts, (KNO_3) acts as the oxidizing agent that triggers the increase in oxidation state of manganese. Understanding which chemicals function as effective oxidizers allows chemists to predict and control the outcomes of redox reactions. The ability to manipulate these reactions is crucial, especially in industrial processes where specific oxidation states of elements are required.

Chemical oxidation-reduction reactions, commonly known as redox reactions, involve the transfer of electrons between substances. During a redox process, one reactant is oxidized (loses electrons) while the other is reduced (gains electrons). The substance that donates electrons—the reducing agent—undergoes oxidation, whereas the one that accepts electrons—the oxidizing agent—undergoes reduction.

The process of converting manganous salts to a higher oxidation state of manganese is a prime example of a redox reaction. In this case, the (KNO_3) and (NaOH) mixture facilitates the transformation by providing a strong oxidative environment. As the Mn ion from the manganous salt is oxidized, we can observe the quintessential characteristics of redox reactions—the simultaneous occurrence of oxidation and reduction. It's the interplay of these two processes that drives the molecular changes we study in redox chemistry.