Question

Which of the following are redox titrations?
A. Complexometric titration
B. Iodometric titration
C. Acid-base titration
D. Back titration
E. All of these

Answer 1

Hint: Redox reactions are the reactions which involve reduction-oxidation or transfer of electrons between reactants. Redox titrations are generally the titrations based on a redox reaction between the titrant and analyte. These are used to determine the concentration of an analyte (whose concentration is to be measured).

Complete step by step answer:
Titration is a process through which the concentration of the unknown solution is calculated using the solution of known solution.
Redox titration is actually a type of titration involving redox reactions i.e. the reactions that involve both reduction and oxidation.
Redox titrations are named according to the type of titrant that is used.
For example:
1. Iodometric titration (uses iodine ${{\text{I}}_{\text{2}}}$)
2. Permanganate titration (uses ${\text{KMn}}{{\text{O}}_{\text{4}}}$) etc.
Complexometric titration is generally used to detect the mixtures of different metal ions present in the solution. It is a type of volumetric analysis. It does not undergo redox reactions.
Iodometric titration is a type of redox titration which definitely involves redox reactions. As we all know iodine (${{\text{I}}_{\text{2}}}$) is a good reducing agent and it reduces the oxidizing agent to which it is titrated against. As this titration involves the reduction-oxidation (redox) reactions it is a redox titration.
Acid-base titration is generally a method for determining the concentration of an acid or base by neutralizing it with the solution of base or acid of known concentration. It is actually quantitative analysis.
Back titration is actually a bit different titration as this is not carried out by taking an analyte as in normal or forward titrations. In this we need to take an excess of another reactant of known concentration to determine the unknown concentration of species.
So, from all the above types of titrations only the iodometric titrations are the redox titrations.

So, the correct answer is “Option B”.

Note:
Always remember the difference between the redox and the other titrations. Redox titrations always occur among redox species i.e. the species that have the capability to undergo reduction-oxidation or what we call as redox reactions.