Chapter 12

Tanning of leather is (a) colouring of leather by chemicals. (b) drying process to make the leather hard. (c) polishing of leather to make it look attractive. (d) coagulative hardening of the leather by chemicals.

Surface tension of lyophilic sol is (a) lower than that of dispersion medium (b) more than that of dispersion medium (c) equal than that of dispersion medium (d) any of these, depending on the dispersion medium

When dilute aqueous solution of \(\mathrm{AgNO}_{3}\) (excess) is added to KI solution, positively charged sol particles of \(\mathrm{AgI}\) are formed due to adsorption of ion (a) \(\mathrm{K}^{+}\) (b) \(\mathrm{Ag}^{+}\) (c) I (d) \(\mathrm{NO}_{3}\)

Which one of the following substances is not used for preparing lyophilic sols? (a) Metal sulphide (b) Gum (c) Gelatin (d) Starch

Which of the following is not a colloidal system? (a) Sugar in water (b) Muddy water (c) Concrete (d) Bread

Tyndall effect in colloidal solution is due to (a) absorption of light (b) scattering of light (c) reflection of light (d) presence of electrically charged particles

Which of the following substances will have least CMC value? (a) \(\mathrm{C}_{6} \mathrm{H}_{13} \mathrm{COOK}\) (b) \(\mathrm{C}_{9} \mathrm{H}_{19} \mathrm{SO}_{3} \mathrm{Na}\) (c) \(\mathrm{C}_{11} \mathrm{H}_{22} \mathrm{NH}_{4} \mathrm{Cl}\) (d) \(\mathrm{C}_{8} \mathrm{H}_{17} \mathrm{COONa}\)

In the styrene foam, the dispersed phase and dispersion medium are, respectively, (a) gas, gas (b) gas, solid (c) solid, solid (d) liquid, solid

What happens when a lyophilic sol is added to a lyophobic sol? (a) Lyophilic sol gets protected by the lyophobic sol. (b) Lyophobic sol is coagulated. (c) Lyophilic sol is coagulated. (d) Lyophobic sol is protected by the lyophobic sol.