On the basis of data given below predict which of the following gases shows least adsorption on a definite amount of charcoal?
| Gas | CO$_2$ | SO$_2$ | CH$_4$ | H$_2$ |
|---|---|---|---|---|
| Critical temp./K | 304 | 630 | 190 | 33 |
In which of the following reactions heterogeneous catalysis is involved?
(i) $2 \mathrm{SO}_2(\mathrm{g})+\mathrm{O}_2(\mathrm{g}) \xrightarrow{\mathrm{NO}(\mathrm{g})} 2 \mathrm{SO}_3(\mathrm{g})$
(ii) $2 \mathrm{SO}_2(\mathrm{g}) \xrightarrow{\mathrm{Pt}(\mathrm{s})} 2 \mathrm{SO}_3(\mathrm{g})$
(iii) $\mathrm{N}_2(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g}) \xrightarrow{\mathrm{Fe}(\mathrm{s})} 2 \mathrm{NH}_3(\mathrm{g})$
(iv) $\mathrm{CH}_3 \mathrm{COOCH}_3(l)+\mathrm{H}_2 \mathrm{O}(l) \xrightarrow{\mathrm{HCl}(l)} \mathrm{CH}_3 \mathrm{COOH}(a q)+\mathrm{CH}_3 \mathrm{OH}(a q)$
At high concentration of soap in water, soap behaves as ......... .
Which of the following will show Tyndall effect?
Method by which lyophobic sol can be protected.