CBSE Questions for Class 12 Engineering Chemistry Surface Chemistry Quiz 2 - MCQExams.com

Which of the following statements does not show correct difference between adsorption and absorption?
  • In adsorption, the substance is concentrated only at the surface while in absorption it is uniformly distributed in the bulk
  • Adsorption is instantaneous while absorption is a slow process
  • A substance can be adsorbed as well as absorbed simultaneously and the process is called sorption
  • Only gases are adsorbed while solids and liquids are absorbed
 When the temperature is lowered and pressure is raised, the adsorption of a gas on a solid?
  • Decreases
  • Increases
  • Remains unaffected
  • Decreases first then increases
Which of the following kinds of catalysis can be explained by the adsorption theory?
  • Heterogeneous catalyst
  • enzyme catalysis
  • homogeneous catalysis
  • acid base catalysis
Physisorption involves:
  • Ionic bonding
  • Covalent bonding
  • Vander walls forces
  • London forces
Select incorrect statement 
  • Micelles are macromolecular colloids
  • The electrical charge on a colliod particle is indicated by electrophoresis
  • Formation of micelles takes place above kraft temperature
  • Formation of micelles takes place below CMC
Arrange cotton, silk, wool and nylon is decreasing order of their water absorption  capacity
  • $$Nylon>cotton>wool>silk$$
  • $$Nylon>cotton>silk>wool$$
  • $$Wool>cotton>silk>nylon$$
  • $$cotton>wool>silk>nylon$$
A substance forms zwitter ion, It can have functional group. 
  • $$ - {\text{N}}{{\text{H}}_{\text{2}}}, - {\text{COOH}}$$
  • $$ - {\text{N}}{{\text{H}}_2}, - {\text{S}}{{\text{O}}_{\text{3}}}{\text{H}}$$
  • Both (A) and (B)
  • None of these
Which of the following gas absorb to a maximum amount by an activated charcoal?
  • $$N_2$$
  • $$O_2$$
  • $$Cl_3$$
  • $$CO_2$$
Adsorption played an important role in:
  • heterogeneous catalysis
  • homogeneous catalysis
  • positive catalysis
  • negative catalysis
The catalyst used in the reduction of perisulphate to sulphate with iodide ion is 
  • $$ Fe^{3+} $$
  • $$ Fe^{2+} $$
  • Both 1 and 2
  • $$ Cr^{2+} $$
The charcoal maintained at $$100^oC$$ adsorbs
  • $$Ne$$ and $$Kr$$
  • $$He$$ and $$Ar$$
  • $$Ar, Kr$$ and $$Xe$$
  • $$He$$ and $$Ne$$
Colloidal solutions of metals like gold, silver and platinum generally prepared by using
  • Peptization
  • Bredig's arc method
  • Exchange of solvent
  • Oxidation method
Adsorption is phenomenon in which a substance
  • Goes into the body of the other substance
  • Remains close the other substance
  • Accumulates on the surface of the other substance
  • None of these
Which of the following substances can be compressed?
  • Sponge
  • Stone
  • Magnet
  • Diamond
Cow milk, an example of neutral emulsion is stabilized by:
  • fat
  • water
  • casein
  • $${ Mg }^{ 2+ }$$ ions
Which of the following statements is incorrect regarding physisorption? 
  • It occurs because of van der Waals forces.
  • More easily liquefiable gases are adsorbed readily.
  • Enthalpy of adsorption (adsorption) is low and positive.
  • Under high pressure it results into multimolecular layer on adsorbent surface.
The following information is available for the reaction: $$R \rightarrow P$$
$$R \rightarrow P; rate = r_{1}$$
$$R \overset{A}\rightarrow P; rate = r_{2}$$
$$R \overset{B}\rightarrow P; rate = r_{3}$$
$$R \overset{C}\rightarrow P; rate = r_{4}$$
$$R \overset{D}\rightarrow P; rate = r_{5}$$
$$R \overset{A + C}\rightarrow P; rate = r_{6}$$
$$R \overset{A+ D}\rightarrow P; rate = r_{7}$$
If $$r_{3} < r_{1} = r_{4} = r_{5} < r_{7} < r_{2} < r_{6}$$, then the only incorrect statement is 
  • B is an inhibitor.
  • C is a catalytic promoter of catalyst A.
  • D is a catalytic poison of catalyst A.
  • A is a catalytic promoter of catalyst C.
Which metal sol (dispersion medium being water) cannot be prepared by Bredig's are method?
  • $$K$$
  • $$Cu$$
  • $$Au$$
  • $$Pt$$
Which of the following reaction is not used in the preparation of colloidal solution?
  • $$2H_{2}S + SO_{2} \rightarrow 3S + 2H_{2}O$$
  • $$2Mg + CO_{2} \rightarrow 2MgO + C$$
  • $$FeCl_{3} + 3H_{2}O \rightarrow Fe(OH)_{3} + 3HCl$$
  • $$2AuCl_{3} + 3SnCl_{2} \rightarrow 2Au + 3SnCl_{4}$$
Select the correct statement(s)
  • If the critical micelle concentration (CMC) of a soap is $$10^{-3} M$$, then $$10^{-4} M$$ solution of this soap will have colloidal nature.
  • Charge on the colloidal particles may be determined with the help of dialysis.
  • Peptization is the process of conversion of a colloidal sol into precipitate by adding some electrolyte.
  • When some oil-soluble dye is added in the water in oil emulsion, the background becomes colored.
The main function of a catalyst in speeding up a reaction is
  • To increase the rate of the forward reaction
  • To change the reaction path so as to decrease the energy of activation for the reaction
  • To reduce the temperature at which the reaction can occur
  • To increase the energy of the molecules of the reactants
A catalyst increases the rate of a chemical reaction by_________
  • increasing the activation energy
  • decreasing the activation energy
  • reacting with reactants
  • reacting with products
Oil soluble dye is mixed with water in oil emulsion. Then
  • dispersion medium is coloured
  • different phase is coloured
  • both coloured
  • none is coloured
Which of the following ion forms primary electrical double layer on the colloidal particle of $$As_{2}S_{3}$$?
  • $$As^{3-}$$
  • $$S^{2-}$$
  • $$H^{+}$$
  • $$OH^{-}$$
In the adsorption of acetic acid on activated charcoal the acetic acid is an 
  • Adsorber
  • Absorber
  • Adsorbent
  • Adsorbate
In emulsions, the dispersion medium and dispersed phase are
  • Both solids
  • Both gases
  • Both liquids
  • One is solid and other is liquid
When the temperature is lowered and pressure is raised the adsorption of a gas on solid 
  • decreases
  • increases
  • remains unaffected
  • decreases first then increases
$$\underset{Sucrose}{{C_{12}H_{22}O_{11}}+H_{2}O}+H_{2}O\overset{dil.\ H_{2}SO_{4}}{\longrightarrow}\underset{Fructose}{C_{6}H_{12}O_{6}(aq)}+\underset{Glucose}{C_{6}H_{12}O_{6}(aq)}$$

In this reaction, dilute $$H_{2}SO_{4}$$ is called
  • Homogeneous catalysis
  • Homogeneous catalyst
  • Homogeneous catalysis
  • Homogeneous catalyst
Which one of the following statements is correct in a reversible reaction?
 A catalyst-
  • increases the rate of forward reaction
  • decreases the rate of forward reaction
  • increases the rate of backward and forward reactions
  • alters the equilibrium constant of the reaction
Which of the following statements is true for a catalyst?
  • It increases the energy of the reactants
  • It decreases the energy of the products
  • It decreases the energy of the reactants
  • It does not change the enthalpy of the reactants
Which of the following catalyses the conversion of glucose into ethanol?
  • Zymase
  • Invertase
  • Maltase
  • Diastase
An emulsion is a colloidal dispersion of 
  • A liquid in a gas
  • A liquid in a liquid
  • A solid in a liquid
  • A gas in a solid
Amongst the following chemical reactions, the one representing homogeneous catalysis is 
  • $$N_{2}(g)+3H_{2}(g)\overset{Fe}{\rightarrow}2NH_{3}(g)$$
  • $$2SO_{2}(g)+O_{2}(g)\overset{2NO}{\longrightarrow}2SO_{3}(g)+2NO(g)$$
  • $$CO(g)+3H_{2}(g)\overset{Ni}{\rightarrow}CH_{4}(g)+{H_{2}O}$$
  • $$2SO_{2}(g)+O_{2}(g)\overset{V_{2}O_{5}}{\rightarrow}2SO_{3}(g)$$
Which one of the following changes when catalyst is used in a reaction?
  • Heat of reaction
  • Product of reaction
  • Equilibrium constant
  • Activation energy
In the titration between oxalic acid and acidified potassium permanganate, the manganous salt formed catalyzes the reaction. The manganous salt is
  • A promoter
  • A positive catalyst
  • An autocatalyst
  • None of these
Platinized asbestos is used as a catalyst in the manufacture of $$H_{2}SO_{4}$$. It is an example of 
  • Heterogeneous catalyst
  • Autocatalyst
  • Heterogeneous catalyst
  • Induced catalyst
In the reversible reaction a catalyst is the substance which
  • Increases the rate of the forward reaction
  • Deceases the value of enthalpy change in the reaction
  • Reduces the time required for reaching the equilibrium state in the reaction
  • Decreases the rate of the reverse reaction
Catalyst used in hydrogenation of oils is
  • Pt
  • Mo
  • Fe
  • Ni
Addition of catalyst in a system
  • Increases equilibrium concentration
  • No effect on equilibrium concentration
  • Decreases equilibrium concentation
  • Increases rate if forward reaction and decreases rate of backward reaction
The colloidal solution of mercury in water can be easily obtained by
  • Mechanical precipitation
  • Bredig's arc method
  • Repeated washing
  • Ultrasonic dispersion
The example of heteropolar sol is:
  • Starch sol in water
  • Rubber sol in water
  • Protein sol in water
  • Sulphur sol
A catalyst is substance which
  • Increase the equilibrium concentration of the product
  • Changes the equilibrium constant of the reaction
  • Shortens the time to reach equilibrium
  • Supplies energy to the reaction
Platinised asbestos helps in the formation of $$SO_{3}$$, from $$SO_{2}$$ and $$O_{2}$$. But, if even a small amount of $$As_{2}O_{3}$$ acts here as
  • A positive catalyst
  • A negative catalyst
  • An autocatalyst
  • A poison
The decomposition of hydrogen peroxide can be slowed by the addition of a small amount of acetamide. The latter acts as a 
  • Detainer
  • Stopper
  • Promoter
  • Inhibitor
Which requires catalyst 
  • $$S+O_{2}\rightarrow SO_{2}$$
  • $$2SO_{2}+O_{2}\rightarrow 2SO_{3}$$
  • $$C+O_{2}\rightarrow CO_{2}$$
  • All
Which one of the following is an incorrect statement for physisorption?
  • It is a reversible process
  • It requires less heat of adsorption
  • It requires activation energy
  • It takes place at low temperature
If some gelatin is mixed in collodial solution of gold, then it does 
  • Coagulation of gold
  • Peptization of gold
  • Protection of gold sol
  • Protection of gelatin
Colloidal solution of arsenious sulphide can be prepared by
  • Electrodispersion method
  • Peptization
  • Double decompositon
  • Hydrolysis
Catalyst used in the oxidation of $$SO_{2}\rightarrow SO_{3}$$
  • Nickel
  • $$ZnO.Cr_{2}O_{3}$$
  • $$V_{2}O_{5}$$
  • Iron
Physical adsorption is inversely proportional to the_____________
  • Volume
  • Concentration
  • Temperature
  • All of these
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