Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R
Assertion A: Permanganate titrations are not performed in presence of hydrochloric acid.
Reason R: Chlorine is formed as a consequence of oxidation of hydrochloric acid.
In the light of the above statements, choose the correct answer from the options given below

We are given the following statements:

Assertion A: Permanganate titrations are not performed in the presence of hydrochloric acid.

Reason R: Chlorine is formed as a consequence of oxidation of hydrochloric acid.

Permanganate ($$KMnO_4$$) is a strong oxidising agent used in redox titrations. In acidic medium, it is typically used with dilute sulphuric acid ($$H_2SO_4$$) rather than hydrochloric acid ($$HCl$$).

The reason is that $$KMnO_4$$ is a strong enough oxidiser to oxidise $$Cl^-$$ ions from HCl to $$Cl_2$$ gas. The reaction is: $$2KMnO_4 + 16HCl \rightarrow 2KCl + 2MnCl_2 + 5Cl_2 + 8H_2O$$.

This is problematic because the $$KMnO_4$$ gets consumed not only by the analyte (the substance being titrated, such as $$Fe^{2+}$$ or oxalate) but also by the $$HCl$$. This leads to an error in the titration — more $$KMnO_4$$ is used than what is needed for the analyte alone, giving incorrect results.

So Assertion A is true — permanganate titrations are indeed not performed with HCl. Reason R is also true — chlorine gas is indeed formed because HCl gets oxidised by the strong oxidising agent $$KMnO_4$$. Moreover, R correctly explains A, because it is precisely the oxidation of HCl to $$Cl_2$$ that causes the problem and is the reason why HCl is avoided.

Hence, the correct answer is Option A: Both A and R are true and R is the correct explanation of A.