Easy MCQ +4 / -1 PYQ · JEE Mains 2022

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.

  1. A Both A and R are true and R is the correct explanation of A. Correct answer
  2. B Both A and R are true but R is NOT the correct explanation of A.
  3. C A is true but R is false.
  4. D A is false but R is true.

Solution

Finest gold sol is red in colour; as the size of particles increases, it appears purple, then blue and finally golden. <br/><br/> 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. <br/><br/> Hence, Both A and R are true and R is the correct explanation of A.

About this question

Subject: Chemistry · Chapter: Surface Chemistry · Topic: Adsorption

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