Question

The transparent colourless solution solution is changed into pale yellow from ___________ in chemical reduction method.

(a) pale blue

(b) Purple

(c) Pale red

(d) Dark brown

This question was addressed to me during an online exam.

This intriguing question comes from Sol-Gel Method and Chemical Reduction Method in portion Nano Materials of Applied Chemistry

Answer 1

Correct answer is (c) Pale red

For explanation I would say: The transparent colourless solution is changed into pale yellow from pale red in the chemical reduction method. Later the dried powder of nano powder of nano silver is obtained by freeze drying.