Alloy is an example of

• gel

• solidified emulsion

• solid solution

• sol

Which of the following is an intrinsic colloid ?

• Glue

• Arsenic sulphide

• Gold

• All of these

Coagulation is not done by

• persistant dialysis

• boiling

• electrophoresis

• peptisation

394.

The homogeneous catalysis is shown by

• Haber's process, N₂ + 3H₂ $\stackrel{\mathrm{Fe}}{\to }$ 2NH₃

• Ostwald process, 4NH₃ + 5O₂ $\stackrel{\mathrm{Pt}}{\to }$ 4NO + 6H₂O

• Contact process, 2SO₂ + O₂ $\stackrel{\mathrm{Pt}}{\to }$ 2SO₃

• 2C₂H₅OH $\stackrel{{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }$ C₂H₅-O-C₂H₅ + H₂O

Which are of the following is a false statement?

• Cell fluid is an example of sol

• Butter is an example of gel

• Hair cream is an example of emulsion

• Cheese is an example of foam

Which of the following statements is correct for Tyndall effect?

• Scattering and polarising of light by small suspended particles is called Tyndall effect

• Tyndall effect of colloidial particles is due to dispersion of light

• Tyndall effect is due to refraction of light

• Tyndall effect is zig-zag motion of suspended particles.

Milk is an emulsion in which

• a gas is dispersed in water

• lactose is dispersed in water

• milk fat is dispersed in water

• a solid is dispersed in water

Micelles are

• adsorbed catalyst

• ideal solution

• gel

• associated colloids

A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium is classified as

• solid sol

• gel

• emulsion

• sol

Which one of the following is used in the hardening of leather?

• Light sensitive silver bromide in gelatin

• Sodium lauryl sulphate

• Alum

• Tannin