Redox Reactions And Electrode Processes

Step 1: Calculate oxidation number: Thus, the oxidation number of Mn in is +6.

Step 1: Understanding Reduction Potential and Reducing Ability The reducing ability of a metal is inversely related to its standard reduction potential. A lower (more negative) reduction potential means a stronger reducing agent. Given , we arrange them in increasing reducing ability as:

- Cr : The ion Cr has the electron configuration . Since Cr can easily lose an electron to become Cr , it acts as a reducing agent, facilitating the reduction of other species by donating electrons.
- Mn : The ion Mn has the electron configuration , which is unstable and readily accepts an electron to stabilize itself as Mn . Hence, Mn acts as an oxidizing agent, accepting electrons from other species.

The equivalent mass of a substance depends on the number of electrons gained or lost per mole of substance in a redox reaction. KMnO shows different oxidation states of Mn in acidic and alkaline media, hence the number of electrons exchanged is different. In acidic medium:
Manganese changes from +7 to +2 oxidation state ( ).
In neutral/alkaline medium:
Manganese changes from +7 to +4 oxidation state ( ).
Therefore, the equivalent mass of KMnO differs because the change in oxidation number of Mn (and hence electrons transferred) is different in acidic and alkaline medium.

Aqueous solutions of HgCl and SnCl cannot co-exist because a redox reaction takes place between them.
- HgCl (mercuric chloride) acts as an oxidizing agent.
- SnCl (stannous chloride) acts as a reducing agent.

Here, Hg in HgCl is reduced to Hg (in Hg Cl ^{2+} _2 ^{4+}$.
Hence, they cannot remain together in the same solution.

Step 1: Define Redox Potential
Redox potential, also known as electrode potential, refers to the tendency of a chemical species to acquire electrons and thereby be reduced. It is measured in volts (V). The standard redox potential is denoted as , which is the potential of a half-cell in standard conditions (1 M concentration, 1 atm pressure, 25°C).
Step 2: Relation to Electrode Reactions
The redox potential indicates how easily a species gains or loses electrons. A positive value indicates that the species is more likely to be reduced (gain electrons), while a negative value suggests that it is more likely to be oxidized (lose electrons). Final Answer: Redox potential quantifies the ability of a species to either gain or lose electrons during redox reactions. Correct Answer: Redox potential refers to the tendency of a species to gain or lose electrons.