Redox Reactions Question 4

Question 4 - 29 January - Shift 2

An indicator ’ $X$ ’ 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 ’ $A$ ’ present in the solution. The indicator ’ $X$ ’ and compound ’ $A$ ’ respectively are

(1) Starch and iodine

(2) Methyl orange and $H_2 O_2$

(3) Starch and $H_2 O_2$

(4) Methyl orange and iodine

Show Answer

Answer: (1)

Solution:

Formula: Starch Iodide Test

$ I^{-}+H_2 O_2 \longrightarrow \underset{(A)}{I_2}+H_2 O $

$I_2+\underset{\text{ (Indicator) }}{Starch} \longrightarrow$ Blue