JEE Main 2022ChemistrySurface ChemistryMediumMCQ

JEE Main 2022Surface Chemistry Question with Solution

JEE Main 2022 (26 Jul Shift 2)

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.

Assertion 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

The colour of colloidal solution depends on the wavelength of light scattered by the dispersed particles. The wavelength of light further depends on the size and nature of the particles. The colour of colloidal solution also changes with the manner in which the observer receives the light. For example, a mixture of milk and water appears blue when viewed by the reflected light and red when viewed by the transmitted light. Finest gold sol is red in colour; as the size of particles increases, it appears purple, then blue and finally golden.

Hence, Both A and R are correct 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.