JEE Main Chemistry - Adsorption and Colloids
Exam Duration: 60 Mins Total Questions : 30
Colloidal solutions of gold prepared by different methods are of different colours because of
- (a)
different diameters of colloidal gold particles
- (b)
Variable valency of gold
- (c)
different concentration of gold particles
- (d)
impurities produced by different methods
Milk is a/an
- (a)
Solution
- (b)
gel
- (c)
emulsion
- (d)
foam
Milk is a colloid in which
- (a)
a liquid is dispersed in liquid
- (b)
a solid is dispersed in liquid
- (c)
a gas is dispersed in liquid
- (d)
some agar-agar is disolved in water
Which one of the following statements is wriong about adsorption?
- (a)
It is a selective and secific process
- (b)
It is a reversible process
- (c)
An increase in the gaseous adsorbate causes increase in adsorption. However, at high pressure, the adsorption becomes constant
- (d)
It is an endothermic process
An emulsifier is an agent which
- (a)
accelerates the dispersion
- (b)
homogenises an emulsion
- (c)
stabilises an emulsion
- (d)
aids the flocculation of an emulsion
Positively charged and negatively charged sols can be distinguished by
- (a)
the addition of 1 : 1 electrolyte
- (b)
the addition of AlPO4
- (c)
the addition of MgSO4
- (d)
electrophoresis
Which one of the following is a lyophillic colloid?
- (a)
milk
- (b)
gum
- (c)
fog
- (d)
blood
Milk can be preserved by adding a few drops of
- (a)
formic acid solution
- (b)
formaldehyde solution
- (c)
acetic acid solution
- (d)
acetaldehyde solution
On adding one ml solution of 10% NaCl to 10 ml gold solution in the presence of 0.25 g of starch, the coagulation is just prevented. Strach has the following gold number.
- (a)
0.025
- (b)
0.25
- (c)
2.5
- (d)
250
Adsorption is multilayer in case of
- (a)
physical adsorption
- (b)
chemisorption
- (c)
BOTH OF THE ABOVE
- (d)
NONE OF THE ABOVE
Zeolites act as shape selective catalysts, the pore size of zeolites ranges from
- (a)
20 to 260 pm
- (b)
260 to 340 pm
- (c)
260 to 400 pm
- (d)
260 to 740 pm
Butter is a colloid formed when
- (a)
fat is dispersed in water
- (b)
fat globules are dispersed in water
- (c)
water is dispersed in a fat
- (d)
NONE OF THESE
The system that is not a colloid:
- (a)
fog
- (b)
milk
- (c)
gold sol
- (d)
wood
Lyophillic colloids are stable due to
- (a)
charge on the particle
- (b)
large size of the particles
- (c)
small size of the particles
- (d)
layer of dispersion medium on the particles
Flocculation value is expressed in terms of
- (a)
mol ml-1
- (b)
milli mole L-1
- (c)
mole L-1
- (d)
gms L-1
Match the following and choose the correct option.
Column I | Column II |
A. Fog B. Milk C. Cheese D. Soap lather |
1. Gel 2. Foam 3. Emulsion 4. Aerosol |
- (a)
A B C D 4 3 1 2 - (b)
A B C D 1 2 3 4 - (c)
A B C D 2 3 1 4 - (d)
A B C D 4 1 3 2
Which of the following is correct for smoke?
- (a)
Dispersion of gas in gas
- (b)
Dispersion of gas in solid
- (c)
Dispersion of solid in gas
- (d)
Dispersion of liquid in gas
For the styrene foam, the dispersed phase and dispersion medium are ............. and ................ respectively.
- (a)
gas, gas
- (b)
solid, gas
- (c)
gas, solid
- (d)
None of the above
Fog is a colloidal system in which
- (a)
liquid dispersed in gas
- (b)
gas dispersed in liquid
- (c)
gas dispersed in solid
- (d)
solid dispersed in liquid
For a positively charged sol, the flocculating power of KCl, MgCl2, CrCl3 and SnCl4 will be in the order
- (a)
MgCl < KCl < CrCl3 < SnCl4
- (b)
KCl = MgCl2 = CrCl3 = SnCl4
- (c)
KCl < MgCl2 < CrCl3 < SnCl4
- (d)
SnCl4 < CrCl3 < MgCl2 < KCl
Which of the following process is responsible for the formation of delta at a place where rivers meet the sea?
- (a)
Emulsification
- (b)
Colloid formation
- (c)
Coagulation
- (d)
Peptisation
When 1 mL of NaCl solution is added to 10 mL gold solution in the presence of 0.0250 g of starch, the coagulation is just prevented. The gold number for starch is
- (a)
0.025
- (b)
0.25
- (c)
2.5
- (d)
25
Gold number of protective colloids A, B, C and D are 0.50, 0.01, 0.10 and 0.005 respectively. The correct order of their protective power is
- (a)
D < A < C < B
- (b)
C < B < D < A
- (c)
A < C < B < D
- (d)
B < D < A < C
The volume of a colloidal particle, Vc as compared to the volume of a solute particle in a true solution Vs , could be
- (a)
\(\frac{V_c}{V_s}=10^3\)
- (b)
\(\frac{V_c}{V_s}=10^{-3}\)
- (c)
\(\frac{V_c}{V_s}=10^{23}\)
- (d)
\(\frac{V_c}{V_s}=1\)
In which of the following solutions interface cannot be obtained?
- (a)
Liquid-liquid
- (b)
solid-liquid
- (c)
Liquid-gas
- (d)
Gas-gas
Extent of adsorption is
- (a)
temperature dependent
- (b)
pressure dependent
- (c)
surface area dependent
- (d)
All of the above
Which of the following is incorrect about adsorption?
- (a)
It increases humidity of atmosphere
- (b)
It decreases humidity of atmosphere
- (c)
It is pressure dependent
- (d)
It is temperature dependent
For Freundlich adsorption isotherm, \({x\over m}=kp^{1/n}\), the value of n is
- (a)
always greater than 1
- (b)
always smaller than 1
- (c)
always equal to 1
- (d)
greater than 1 at low temperature and smaller than 1 at high temperature
Point out the correct statement for chemisorption.
- (a)
It is exothermic and monolayered
- (b)
It is endothermic and monolayered
- (c)
It has enthalpy of adsorption in between 0-5kal mol-1
- (d)
All of the above
According to Freundlich adsorption isotherm, which of the following is correct?
- (a)
\({x\over m}\propto p^o\)
- (b)
\({x\over m}\propto p^1\)
- (c)
\({x\over m}\propto p^{1/n}\)
- (d)
All are correct