The critical temperature of $A, B, C, D$ gases are 190 K , $630 \mathrm{~K}, 261 \mathrm{~K}, 400 \mathrm{~K}$ respectively. The quantity of gas adsorbed per gram of charcoal at same pressure is least for the gas

' $A$ ' is a protecting colloid. The following data is obtained for preventing the coagulation of 10 mL of gold sol to which 1 mL of $10 \% \mathrm{NaCl}$ is added. What is the gold number of ' $A$ '?

Expt. No.	Wt (in mg ) of $\boldsymbol{A}$ added to gold sol	$$ \text { Coagulation } $$
1	40	Prevented
2	35	Prevented
3	25	Not prevented
4	32	Not prevented
5	33	Prevented

The following data is obtained for coagulating a positively charged sol in 2 hours

Conc. of $\mathrm{Cl}^{-}$in $\mathrm{mol} \mathrm{L}^{-1}$	Result
$$ 5 \times 10^{-5} $$	Sol not precipitated
$$ 6 \times 10^{-5} $$	Sol not precipitated
$$ 7 \times 10^{-5} $$	Sol precipitated
$$ 8 \times 10^{-5} $$	Sol precipitated
$$ 1 \times 10^{-4} $$	Sol precipitated

What is the coagulating value of electrolyte for this sol?

$$ \text { Match List - I, with List-II. } $$

$$ \begin{array}{llll} \hline & \text { List I } & & \text { List II } \\ \hline \text { I } & \text { Colloidal antimony } & \text { A } & \text { Kalaazar } \\ \hline \text { II } & \text { Silver sol } & \text { B } & \text { Intermuscular injection } \\ \hline \text { III } & \text { Milk of magnesia } & \text { C } & \text { Eye lotion } \\ \hline \text { IV } & \text { Gold sol } & \text { D } & \text { Stomach disorder } \\ \hline \end{array} $$