- Exam
- JEE Main
- Year
- 2022
- Date
- 26 July
- Shift
- Evening Shift
- Subject
- Chemistry
- Chapter
- Surface Chemistry
JEE Main 2022 · 26 July · Evening Shift · Chemistry · Surface Chemistry
Given below are two statements: one is labelled as Assertion A and...
Given below are two statements: one is labelled as
Assertion and the other is labelled as Reason .
Assertion : Finest gold is red in colour, as the size of the particles increases, it appears purple then blue and finally gold.
Assertion : 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
Options
- ABoth and are true and is the correct explanation of
- BBoth and are true but is NOT the correct explanation of
- C is true but is false
- D is false but is true
Correct answer
A. Both and are true and is the correct explanation of
Step-by-step solution
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.