The purple of Cassius is due to the presence of $......$.

In the following reaction for the preparation of gold sol,$a, b, c, x, y$ and $z$ are $a AuCl_3 + b HCHO + c H_2 O \longrightarrow x Au (\text{sol}) + y HCO_2 H + z HCl$. Find the correct values for the coefficients.

Hair cream is an example of which of the following?

Which of the following is an example of two-dimensional nanostructures?

The Tyndall effect depends upon the

From the following,which will have maximum coagulating power for $As_2S_3$ sol?