Which of the following statement is not correct?
Adsorption energy for chemical adsorption is generally greater than that of physical adsorption
Physical adsorption is due to van der Waal forces
Physical adsorption decreases at high temperature and low pressure
Physical adsorption is irreversible
D.
Physical adsorption is irreversible
Among all the statements, statement d is incorrect. Physical adsorption is due to van der Waal's forces which are weak forces, hence this type of adsorption is reversible and not irreversible.
Arsenic sulphide sol is prepared by passing H2S through arsenic oxide solution. The charge developed on the particles is due to adsorption of :
H+
S2-
OH-
O2-
Which one of the following colloidal solution is positive sol?
Gelatin in strongly acidic solution
Smoke
Dlay soil
Blood
A emulsifier is a substance which :
stabilises the emulsion
homogenises the emulsion
coagulates the emulsion
accelerates the dispersion of liquid in liquid
The coagulation of 200 mL of a positive colloid took place when 0.73 g HCl was added to it without changing the volume much. The flocculation value of HCl for the colloid is
100
36.5
0.365
150
Paints and hair creams are respectively
sol and emulsion
aerosol and foam
emulsion and sol
foam and gel.
Extent of adsorption of adsorbate from solution phase increases with :
increase in amount of adsorbate in solution
decrease in surface area of adsorbent
increase irtemperature of solution
decrease in amount of adsorbate in solution