Redox Reactions

After balancing change in oxidation state,

2Cl₂ $\stackrel{}{\to }$ 2Cl^– + 2ClO^–

Next, balance 'O' atoms,

2Cl₂ +4OH^– $\stackrel{}{\to }$  2Cl^– + 2ClO^–+ 2H₂O

Simplifying to get the simplest ratios,

Cl₂ +2OH^– $\stackrel{}{\to }$ Cl^–+ClO^–+ H₂O

x = 1, y = 2, z = 1, p = 1

Disproportionation reaction is a reaction in which a substance (element) is simultaneously oxidised and reduced.

Potassium hydrogen phthalate is used to standardize NaOH solutions.

Phenolphthalein is used as an indicator to detect completion of titrations.

meq. of K₂Cr₂O₇ = meq. of NO^–₂

n₁ * 6 = 1 * 2

n₁=1/3

Oxidation no. of a substance is proportional to the charge on it. In this case the charge is + 6 hence oxidation state will be +6

In NEET exam, there can be 1 to 2 questions from redox reactions, carrying 4-8 marks. The weightage is around 2% to 4%. In JEE Main, the weightage of this chapter is from 3.3% to 4-6%. You can expect nearly 1 to 2 questions from this chapter.

The applications of redox reactions include in cellular respiration, and batteries. In industries, these are used in the chemical production, metal extraction and water treatment. 

The redox reactions are significant for some of the basic functions of life such as respiration, photosynthesis, corrosion or rusting and combustion.

There are four types of redox reactions. These are combination, Decomposition, Displacement, and Disproportionation.
In the combination redox reaction, two or more substances form a single product, in decomposition reactions, a compound breaks down into two or more substances. When one element in a compound replaces another, it is called displacement reactions. When simultaneously, one substance is oxidized and reduced, the reaction is known as the disproportionation redox reaction.