Observe the following reaction

I. $\mathrm{CO}(\mathrm{g})+\mathrm{H}_2(\mathrm{~g}) \xrightarrow{X} \mathrm{HCHO}(\mathrm{g})$

II. $\mathrm{CO}(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g}) \xrightarrow{\gamma} \mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g})$

The catalysts $X$ and $Y$ in the above reactions are respectively

The correct statements about the properties of colloidal solutions are

A. Tyndall effect is used to distinguish between a colloidal solution and a true solution.

B. Zeta potential is related to movement of colloidal particles.

C. Brownian motion in colloidal solution is faster if the viscosity of the solution is very high.

D. Brownian motion stabilises the sols.

$$ \text { Match the following. } $$

$$ \begin{array}{llll} \hline & \text { List-I (Type of colloid) } & & \text { List-II (Example) } \\ \hline \text { A } & \text { Sol } & \text { I } & \text { Cloud } \\ \hline \text { B } & \text { Foam } & \text { II } & \text { Whipped cream } \\ \hline \text { C } & \text { Gel } & \text { III } & \text { Paint } \\ \hline \text { D } & \text { Aerosol } & \text { IV } & \text { Butter } \\ \hline \end{array} $$

The correct answer is

The most effective coagulating agent for antimony sulphide sol is