30 questions
How adsorption process take place?
separation through liquid and gases
separation through solid
In adsorption from liquid process, choose what type of adsorbent usually use in this unit.
Carbon
Zeolite
Silica
Activated carbon
Definition of irreversible adsorption.
Amount of adsorbed is proportional to the concentration in the fluid.
low solid loadings are obtained and because it leads to quite long mass-transfer zones in the bed.
Amount of adsorbed is independent of concentration down to very low values
Choose the correct type of adsorption
liquid sorption
ion exchange
chemisorption
Physisorption
Properties of good adsorbent
granular
porous material
high surface area to unit mass
high unit mass to surface area
Choose importance of regeneration to adsorbent.
removal of adsorbent
removal of unknown particles
removal of adsorbates
reduce activation energy of reaction
Define adsorption isotherm.
equilibrium relationship between the concentration in the fluid phase and the concentration in the adsorbate particles
equilibrium relationship between the concentration in the fluid phase and the concentration in the adsorbent particles
equilibrium relationship between the concentration in the gas phase and the concentration in the adsorbent particles
equilibrium relationship between the concentration in the gas phase and the concentration in the adsorbate particles
Identify type of adsorber based on the figure above.
Gas-drying equipment
Vapor phase adsorption
Pressure swing adsorption
Fixed bed adsorber
Which of the following is not an adsorbent?
a) Carbon
b) Polymers and resins
c) Clay
d) Dry sponge
What do you mean by the term “Sorption”?
a) Attachment
b) Detachment
c) Diffusion
d) Thermal Expansion
4. Which of the following isotherm is applicable to physical adsorption?
a) Langmuir
b) BET
c) Freundlich
Which type of isotherm is given from the figure, Choose from the following options?
a) Type 1 Adsorption isotherm
b) Type 2 Adsorption isotherm
c) Type 3 Adsorption isotherm
d) Type 4 Adsorption isotherm
Calculate the adsorption of a dye on activated carbon at 25°C, where k = 0.025, n = 0.5 and C = 0.04.
Based on the Freundlich isotherm. (q = K.d C1/n)
a) 0.050
b) 0.030
c) 0.040
d) 0.060
Which of the following statements regarding the physical adsorption of a gas on surface of solid is not correct?
a) On increasing temperature, adsorption increases continuously
b) Enthalpy changes are negative
c) Adsorption is specific
d) It is reversible in nature
8. Which of the following is not characteristic of chemisorption?
a) It is irreversible
b) It is specific
c) It is multilayer phenomenon
d) Heat of adsorption is about 400kj
For an adsorbant-adsorbate system obeying the Langmuir adsorption isotherm, b = 0.48 bar-1 and p = 0.16 bar-1. At what pressure will 50% of the surface be covered? [ hint: ]
a) 0.05 bar
b) 0.07 bar
c) 0.08 bar
d) 0.04 bar
What is adsorption?
The ability for compounds to react with each other
The attachment of one compound to the surface of another compound
The release of one compound from the surface of another compound
The incorporation of one compound into another compound
Activated carbon removes microbial contaminants effectively.
a) True
b) False
The filter once installed need not to be replaced in activated carbon filtration.
a) True
b) False
___________ has high degree of porosity.
a) Alum
b) Carbon
c) Aluminium
d) Zinc
Which of the following is not removed by activated carbon?
a) Odour
b) Chlorine
c) Microbes
d) Micro-pollutants
On which principle does the particulate filters work?
a) Particle’s size
b) Absorb contaminant
c) Reacts with contaminant
d) Adsorb contaminant
What is the average surface area of one gram of carbon?
d) 4000 m2
c) 3000 m2
b) 2000 m2
a) 1000 m2
What is the minimum temperature required for carbonization?
d) 800˚C
c) 600˚C
a) 200˚C
b) 400˚C
Chemical adsorption takes place at high temperature.
False
True
Which force holds the molecules in physical adsorption?
Nuclear force
Tension force
Van der waals force
Friction force
Chemical adsorption is also called as _____
Chemical sorption
Chemiption
Chemisorption
Sorption
Physical adsorption is also called as _________
Sorption
Physisorption
Absorption
Adsorption
What is the highest enthalpy of adsorption for chemical adsorption?
400 KJ mol-1
300 KJ mol-1
200 KJ mol-1
100 KJ mol-1
What is the lowest enthalpy of adsorption for physical adsorption?
25 KJ mol-1
15 KJ mol-1
10 KJ mol-1
5 KJ mol-1