0.1 M solution of KI reacts with excess of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) and \(\mathrm{KIO}_{3}\) solution. According to equation \(5 \mathrm{I}^{-}+\mathrm{IO}_{3}^{-}+6 \mathrm{H}^{+} \rightarrow 3 \mathrm{I}_{2}+3 \mathrm{H}_{2} \mathrm{O}\) Identify the correct statements : (A) 200 mL of KI solution reacts with 0.004 mol of \(\mathrm{KIO}_{3}\) (B) 200 mL of KI solution reacts with 0.006 mol of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (C) 0.5 L of KI solution produced 0.005 mol of \(\mathrm{I}_{2}\) (D) Equivalent weight of \(\mathrm{KIO}_{3}\) is equal to \(\left(\frac{\text { Molecular weight }}{5}\right)\) Choose the correct answer from the options given below:

Redox Reactions and Electrochemistry — JEE Main · 2025 · 29 Jan 2025 · Shift 2 Question with Solution

0.1 M solution of KI reacts with excess of

H_{2} SO_{4}

and

KIO_{3}

solution. According to equation

5 I^{-} + IO_{3}^{-} + 6 H^{+} \to 3 I_{2} + 3 H_{2} O

Identify the correct statements :
(A) 200 mL of KI solution reacts with 0.004 mol of

KIO_{3}

(B) 200 mL of KI solution reacts with 0.006 mol of

H_{2} SO_{4}

I_{2}

(D) Equivalent weight of

KIO_{3}

is equal to

(\frac{Molecular weight}{5})

Choose the correct answer from the options given below:

Answer: (A)

The balanced equation

5 I^{-} + I O_{3}^{-} + 6 H^{+} \to 3 I_{2} + 3 H_{2} O

fixes the stoichiometry. 200 mL of 0.1 M KI gives

n (I^{-}) = 0.2 \times 0.1 = 0.02

mol. Since 5 mol

I^{-}

reacts with 1 mol

I O_{3}^{-}

, the

K I O_{3}

consumed is

0.02/5 = 0.004

mol — (A) is correct. The same 0.02 mol

I^{-}

requires

6/5 \times 0.02 = 0.024

mol

H^{+}

, which needs

0.024/2 = 0.012

mol

H_{2} S O_{4}

(each

H_{2} S O_{4}

supplies 2

H^{+}

), not 0.006 mol — (B) is false. For 0.5 L of 0.1 M KI,

n (I^{-}) = 0.05

mol, giving

I_{2} = (3/5) \times 0.05 = 0.03

mol, not 0.005 mol — (C) is false. In this reaction iodine in

I O_{3}^{-}

goes from +5 to 0 in

I_{2}

, a 5-electron change per iodine atom, so the equivalent weight of

K I O_{3}

Molecular weight /5

— (D) is correct. Statements (A) and (D) alone are true.

JEE Main · 2025 · 29 Jan 2025 · Shift 2 · Single correct option