JEE Main 2022ChemistrySurface ChemistryColloidseasyMCQ

JEE Main 2022 — Surface Chemistry Question with Solution

From: JEE Main 2022 (Online) 26th July Evening Shift

Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Finest gold is red in colour, as the size of the particles increases, it appears purple then blue and finally gold.

Reason R : The colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles.

In the light of the above statements, choose the most appropriate answer from the options given below.

Choose an option

Show full solutionCorrect option: A
Correct answer
ABoth A and R are true and R is the correct explanation of A.

Step-by-step explanation

Finest gold sol is red in colour; as the size of particles increases, it appears purple, then blue and finally golden.

The colour of colloidal solution depends on the wavelength of light scattered by the dispersed particles. The wavelength of light further depends on size and nature of the particles.

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

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About this question

This is a previous-year question from JEE Main 2022, covering the Surface Chemistry chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.