Which one of the following statements is true?

• Saponification of oil yields a diol

• Drying of oil involves hydrolysis

• Addition of antioxidant to oil minimizes rancidity

• Refining of oil involves hydrogenation

During the adsorption of krypton on activated charcoal at low temperature

• $∆$H < 0 and $∆$S < 0

• $∆$H > 0 and $∆$S < 0

• $∆$H > 0 and $∆$S > 0

• $∆$H < 0 and $∆$S > 0

Which one of the following does not involve coagulation?

• Clotting of blood by the use of ferric chloride

• Formation of delta region

• Treatment of drinking water by potash alum

• Peptization

Which one of the following is an example for homogeneous catalysis?

• Manufacture of sulphuric acid by Contact process

• Manufacture of ammonia by Haber's process

• Hydrolysis of sucrose in presence of dilute hydrochloric acid

• Hydrogenation of oil

The stability of a lyophobic colloid is due to

• adsorption of covalent molecules on the colloid

• the size of the particles

• the charge on the particles

• Tyndall effect

Which of the following cations will have minimum flocculation value for arsenic sulphide sol?

• Na⁺

• Mg²⁺

• Ca²⁺

• Al³⁺

Adsorption theory is applicable for

• homogeneous catalysis

• heterogeneous catalysis

• autocataylsis

• induced catalysis

All colloidal dispersions have

• low osmotic pressure

• no osmotic pressure

• high osmotic pressure

• very high osmotic pressure

Silver iodide is used for producing artificial rain because AgI

• is easy to synthesize

• has crystal structure similar to ice

• is insoluble in water

• is easy to spray at high altitude

During the adsorption of a gas on the surface of a solid, which of the following is true?

• $∆\mathrm{G} > 0, ∆\mathrm{H} < 0, ∆\mathrm{S} < 0$

• $∆\mathrm{G} < 0, ∆\mathrm{H} < 0, ∆\mathrm{S} < 0$

• $∆\mathrm{G} <\hspace{0.17em}0, ∆\mathrm{H} < 0, ∆\mathrm{S} > 0$

• $∆\mathrm{G} <\hspace{0.17em}0, ∆\mathrm{H} > 0, ∆\mathrm{S} < 0$