JEE · NEET Previous Year Question

An indicator ${}^C$X' is used for studying the effect of variation in concentration of iodide on the rate of reaction of iodide ion with $H_2{O}_2$ at room temp. The indicator 'X' forms blue colored complex with compound ${}^C$A' present in the solution. The indicator 'X' and compound 'A' respectively are

Topic: JEE PYQ

Answer: A. Full step-by-step solution below.