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Colloidal solution of gold prepared by different methods of different colours because of:
The colour of colloidal solutions depends upon the size of the colloidal particles.
Which one of the following statements is not correct?
(b) For a reversible reaction. it accelerates the speed of forward as well as backward reaction to the same extent. Hence, it does not disturb the equilibrium, i.e. does not change the equilibrium constant of the reaction but helps to attain the equilibrium faster.
The coagulation values in millimoles per litre of the electrolytes used for the coagulation of As2S3 are given below
I. (NaCl) =52 II. (BaCl2) =0.69
III. (MgSO4) = 0.22
The correct order of their coagulating power is
(c) Lower the coagulating power, higher is the coagulation value in millimoles per litre, i.e coagulating power is inversely proportional to coagulation values. Thus, correct order of coagulating power is
MgSO4 > BaCl2 > NaCl
or III>II>I
The addition of a catalyst during a chemical reaction alters which of the following quantities?
Which one of the following characteristics is associated with adsorption?
(a) Adsorption is a spontaneous process that occurs with release in energy and decrease. In the randomness (i.e. entropy) of the adsorbed substance.
For a spontaneous process, G must be negative.
G = H - TS
As the process is exothermic and randomness of molecule (entropy) decreases hence, both H and S will be negative as well.
Fog is a colloidal solution of:-
(d) Fog is a colloidal solution of liquid in a gas, in which liquid is the dispersed phase whereas gas is the dispersion medium.Examples of other options are as follows:
Gas in liquid: Shaving cream, soda water froth
Solid in gas: Dust in air
Gas in gas : Atmospheric air
Which property of colloidal solution is independent of charge on the colloidal particles?
Coagulation is generally brought about by the addition of electrolytes. When an electrolyte is added to a colloidal solution, the particles of the sol take up the ions which are oppositely charged. As a result their charge gets neutralised.
Electrophoresis The movement of colloidal particles under an applied electric potential is called electrophoresis. Electrophoresis may be defined as a phenomenon in which the molecules of the dispersion medium are allowed to more under the influence of an electric field whereas colloidal particles are not allowed to more.
Tyndall effect is the scattering of light by sol particles, which cannot be affected by charge on them.
In Freundlich adsorption isotherm, the value of 1/n is
In Freunlich adsorption isotherm,
x/m = kp1/n
the value of n is always greater than 1. So, the value of 1/n lies between 0 and 1 in all cases.
Which one of the following statements is incorrect about enzyme catalysis?
Most of the enzymes have proteinous nature. They are highly specific and get denaturated by high temperature or UV rays. At optimum temperature, which is generally in between 25°-35°C, enzyme activity is maximum.
The protecting power of lyophilic colloidal sol is expressed in terms of
Lyophobic sols are unstable, so they are stabilised by adding some lyophilic colloids which protect them from precipitation. Thus, lyophilic colloids are called protecting colloids. Their protecting power is expressed in terms of gold number.
Note: Lesser the gold number, higher is the protecting power
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