Animal charcoal is used in decolorising colour of liquids because it is a good
adsorbate
adsorbent
oxidising agent
reducing agent
Which one of the following statements is not correct?
Physical adsorption decreases with increase in the temperature
Physical adsorption is multtlayered
Activation energy of physical adsorption is very high
Enthalpy change of physical adsorption is about 20 kJ mol
Which of the following is a lyophobic colloidal solution?
Aqueous starch solution
Aqueous protein solution
Gold sol
Polymer solutons in some organic solvents
Which of the following is an example for heterogeneous catalysis reaction ?
Hydrolysis of aqueous sucrose solution in the presence of aqueous mineral acid
Hydrolysis of liquid in the presence of aqueous mineral acid
The disperse phase, dispersion medium and nature of colloidal solution (lyophilic or lyophobic) of 'gold sol' respectively are :
solid, solid, lyophobic
liquid, liquid, lyophobic
solid, liquid, lyophobic
solid, liquid, lyophilic
C.
solid, liquid, lyophobic
The disperse phase, dispersion medium and nature of colloidal solution of 'gold sol' are solid, liquid and lyophobic respectively.
Colloidal solution of gold is obtained when dispersed phase is solid and dispersion medium is liquid. Substances like metals cannot be brought into the colloidal state simply by bringing them in contact with water and therefore, special methods are devised for the purpose. Hence, they are known as hydrophobic or lyophobic colloids.
Assertion (A) : A catalyst increases the rate of a reaction.
Reason (R) : In presence of a catalyst, the activation energy of the reaction increases.
The correct answer is
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is not the correct explanation of (A).
(A) is true, but (R) is not true
(A) is not true, but (R) is true
Which of the following is not correct?
Milk is a naturally occurring emulsion
Gold sol is a lyophilic sol
Physical adsorption decreases with rise in temperature
Chemical adsorption is unilayered
Which one of the following gives a straight line for Freundlich adsorption isotherm?
log vs log p
log