Which one of the following is used in the hardening of leather?
Light sensitive silver bromide in gelatin
Sodium lauryl sulphate
Alum
Tannin
D.
Tannin
Animal leather is colloidal in nature and has positively charged particles. When it is soaked in tannin, a negatively charged colloid, it result in mutual coagulation and gets harden. Thus, leatrher get harderned after tanning.
Which of the following is true for spontaneous adsorption of H2 gas without dissociation on solid surface.
Process is exothermic and ΔS <0.
Process is exothermic and ΔS >0
Process is endothermic and ΔS <0.
Process is endothermic and ΔS >0.
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 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
At Critical Micell Concentration (CMC), the surfactant molecules
dissociate
associate
become completely soluble
decompose
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
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.
