Chemistry - Adsorption and Colloids Question Paper 1
Exam Duration: 45 Mins Total Questions : 19
A colloid can be purified by
- (a)
coagulation
- (b)
electro-osmosis
- (c)
dialysis
- (d)
cataphoresis
How many layers are adsorbed in chemical adsorption?
- (a)
one
- (b)
two
- (c)
many
- (d)
zero
Catalyst only
- (a)
decreases activation engergy
- (b)
increases activation engergy
- (c)
brings about equilibrium
- (d)
NONE OF THESE
The size of colloidal particles have the following range?
- (a)
above 10-4 cm
- (b)
10-7 to 10-6 cm
- (c)
10-7 to 10-5 cm
- (d)
NONE OF THE ABOVE
Surface tension of lyophilic sols is
- (a)
lower than that of water
- (b)
more than that of water
- (c)
equal to that of water
- (d)
NONE OF THE ABOVE
Which one of the following is adsorbed into maximum amount by activated charcoal?
- (a)
N2
- (b)
CO2
- (c)
Cl2
- (d)
O2
Which one of the following is less then zero during adsorption?
- (a)
\(\Delta \)G
- (b)
\(\Delta \)S
- (c)
\(\Delta \)H
- (d)
ALL THE ABOVE
Peptisation is a process of
- (a)
precipitation of colloidal particles
- (b)
purification of colloids
- (c)
dispersing precipitate into colloidal sols
- (d)
movement of colloidal particles in the electrical field
Which of the following is correct regarding the size of true solution, suspension and colloidal solution?
- (a)
Suspension > Colloidal solution > True solution
- (b)
True solution > Suspension > Colloidal solution
- (c)
Suspension > Colloidal solution = True solution
- (d)
None of the above
Which of the following is a macromolecular colloidal particle?
- (a)
S8 particle
- (b)
Fine gold particle
- (c)
Protein
- (d)
Soap molecules
What will be the type of colloidal solution, when airborn bacteria and virus are mixed with each other?
- (a)
Solid, gas
- (b)
Solid, solid
- (c)
Gas, solid
- (d)
Solid, liquid
In general, the smoke is bluish due to
- (a)
scattering
- (b)
coagulation
- (c)
Brownian motion
- (d)
electrosmosis
Colloidal solution is prepared from suspension by means of
- (a)
peptisation
- (b)
condensation
- (c)
sedimentation
- (d)
fragmentation
Method by which lyophobic sol can be protected is
- (a)
by addition of oppositely charged sol
- (b)
by addition of an electrolyte
- (c)
by addition of lyophilic sol
- (d)
by boiling
What is the cause of Brownian movement?
- (a)
The impact of molecules of the dispersion medium on the colloidal particles
- (b)
The movement of negatively charged particles to the positively charged particle
- (c)
Attractive forces exist between the colloidal particle and the molecules of dispersion medium
- (d)
The enthalpy change during the formation of colloids
Amongst the following, the surfactant which will form micelles in aqueous solution at the lowest molar concentration at ambedient conditions is
- (a)
CH3(CH2)15N+(CH3)3Br-
- (b)
CH3(CH2)11OSO3-Na+
- (c)
CH3(CH2)6COO-Na+
- (d)
CH3(CH2)11N+(CH3)3Br-
The dispersed phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged respectively. Which of the following statement is not correct?
- (a)
Coagulation in both sols can be brought about by electrophoresis
- (b)
Mixing the sols has no effect
- (c)
Sodium sulphate solution causes coagulation causes in both sols
- (d)
Magnesium chloride solution coagulates the gold sol more readily than the iron (III) hydroxide sol
During adsorption, which of the following has negative value?
- (a)
\(\Delta H\)
- (b)
\(\Delta G\)
- (c)
\(\Delta S\)
- (d)
All of these
Choose the incorrect statement.
- (a)
Physisorption is a reversible phenomenon having enthalpy of adsorption about 5kcal mol-1
- (b)
Physisorption is multilayer phenomenon
- (c)
Chemisorption occurs at low temperature.
- (d)
chemisorption occurs due to chemical forces between adsorbate and adsorbent