In the following equation x\ KI + H_2O_2 → I_2 + y\ KOH x and y respectively are : (A) 2, 2 (B) 1, 2 (C) 2, 1 (D) 1, 1

ScienceCBSE Class 10 · Board exam 2026, set 31/3/1 · 1 mark · MCQ

CBSE Class 10 Science 2026: question 19

Set in the CBSE Class 10 board exam of 2026, paper 31/3/1, section B, question 19, for 1 mark. Try it first; the hints and our step-by-step solution are below.

Q19 · 1 mark · MCQChemical Reactions and Equations

In the following equation

$x KI + H_{2} O_{2} \to I_{2} + y KOH$

x and y respectively are :

(A)2, 2
(B)1, 2
(C)2, 1
(D)1, 1

Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 31/3/1.

Hints

Open one hint at a time and try again before the next.

Hint 1

Balance iodine atoms first.

Hint 2

Then balance potassium, and check O and H.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

$I_{2}$ needs 2 I atoms, so x = 2. Then 2 K atoms give y = 2.
Check: $2KI + H_{2} O_{2} \to I_{2} + 2KOH$ gives O: 2 = 2 and H: 2 = 2, so it is balanced. Option (A).
1 mark

Answer: (A) 2, 2

Where the marks are

x = 2, y = 2 (1 mark)

Revise the chapter

Chapter: Chemical Reactions and Equations (notes, formulas, where marks are lost and every past question)
Topic: Balancing Chemical Equations

Practise this chapterBoard-style questions from Chemical Reactions and Equations, one at a time, marked against the answer key and marking points.Back to the full paper2026 board paper, set 31/3/1: every question, by section.

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CBSE Class 10 Science 2026: question 19

Hints

Step-by-step solution

Revise the chapter

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