CBSE Questions for Class 12 Engineering Chemistry Surface Chemistry Quiz 9 - MCQExams.com

Which of the following interfaces cannot be obtained?
  • Liquid-Liquid
  • Solid-Liquid
  • Liquid-Gas
  • Gas-Gas
Match the column I with column II with respect to applications of properties of colloids in different fields and mark the appropriate choice. 
Column IColumn II
(A) Coagulation(i) Colloidal medicines
(B) Adsorption(ii) Photographic films
(C) Electrophoresis(iii) Sewage disposal
(D) Emulsions(iv) Smoke precipitator
  • (A) $$\rightarrow$$ (iii), (B) $$\rightarrow$$ (i), (C) $$\rightarrow$$ (ii), (D) $$\rightarrow$$ (iv)
  • (A) $$\rightarrow$$ (ii), (B) $$\rightarrow$$ (iii), (C) $$\rightarrow$$ (i), (D) $$\rightarrow$$ (iv)
  • (A) $$\rightarrow$$ (iii), (B) $$\rightarrow$$ (i), (C) $$\rightarrow$$ (iv), (D) $$\rightarrow$$ (ii)
  • (A) $$\rightarrow$$ (i), (B) $$\rightarrow$$ (iv), (C) $$\rightarrow$$ (iii), (D) $$\rightarrow$$ (ii)
Which one of the following is not applicable to the phenomenon of adsorption?
  • $$\Delta H>0$$
  • $$\Delta G<0$$
  • $$\Delta S<0$$
  • $$\Delta H<0$$
At the equilibrium position in the process of adsorption_________.
  • $$\Delta H>0$$
  • $$\Delta H=T\Delta S$$
  • $$\Delta H>T \Delta S$$
  • $$\Delta H=0$$
Which of the following will form a reversible sol?
  • Gold sol
  • Sulphur sol
  • Rubber sol
  • Arsenous sulphide sol
Alcohols can be converted to various types of gasoline(period) by shape-selective catalyst.
  • Maltase
  • ZSM-$$5$$
  • Lindlar's catalyst
  • Ziegler Natta catalyst
Which of the following statements given about emulsions is incorrect?
  • The droplets in emulsions are often negatively charged and can be precipitated by electrolytes.
  • Emulsion can be diluted with any amount of the dispersed liquid. On the other hand, the dispersion medium when mixed, forms a separate layer.
  • Emulsions can be broken into constituent liquids by heating, freezing, centrifuging, etc.
  • Emulsions also show Brownian movement and Tyndall effect.
Which of the following statements are correct?
(i)   When an animal hide, which has negatively charged particles, is soaked in tannin, which contains positively charged colloidal particles, mutual coagulation does not take place.
(ii) Photographic films are prepared by coating an emulsion of the light sensitive silver bromide in gelatin over glass plates or celluloid films.
(iii) Latex is a colloidal solution of rubber particles which are negatively charged.
(iv) In Cottrell precipitator, the smoke, before it comes out from the chimney, is led through a chamber containing plates having a charge opposite to that carried by smoke particles. The particles on coming in contact with these plates acquire some charge and do not get precipitated.
  • (i) and (iv) only
  • (ii) and (iii) only
  • (ii), (iii) and (iv) only
  • All of these.
Extent of physisorption of a gas increases with:
  • increase in temperature
  • decrease in temperature
  • decrease in surface area of adsorbent
  • decrease in strength of van der Waals forces
Freshly prepared precipitate sometimes gets converted to colloidal solution by:
  • coagulation
  • electrolysis
  • diffusion
  • peptisation
In which of the following reactions heterogeneous catalysis is involved?
(I) $$2SO_{2}$$ + $$O_{2}$$   $$\overset{V_{2}O_{5}}{\longrightarrow}$$   $$2SO_{3}$$
(II) $$2SO_{2}$$ + $$O_{2}$$   $$\overset{NO_{(g)}}{\longrightarrow}$$   $$2SO_{3}$$
(III) $$2N_{2} + 3H_{2}$$   $$\overset{Fe}{\longrightarrow}$$   $$2NH_{3}$$
(IV) $$CH_{3}COOCH_{3}$$ + $$H_{2}O$$   $$\overset{HCl_{(aq)}}{\longrightarrow}$$   $$CH_{3}COOH$$ + $$CH_{3}OH$$
  • (I), (III)
  • (II), (III), (IV)
  • (I), (II), (III)
  • (IV)
In physisorption adsorbent does not show specificity for any particular gas because:
  • involved van der waals forces are universal
  • gases involved behave like ideal gases
  • enthalpy of adsorption is low
  • it is a reversible process
Which of the following phenomenon is applicable to the process shown in the figure?
934035_5599eeda5e08401386363883890da9be.png
  • Absorption
  • Adsorption
  • Coagulation
  • Emulsification
Which of the following is not a favourable condition for physical adsorption?
  • High pressure
  • Negative $$\Delta H$$
  • Higher critical temperature of adsorbate
  • High temperature
Which of the following is an example of absorption?
  • Water on silica gel
  • Water on calcium chloride
  • Hydrogen on finely divided nickel
  • Oxygen on metal surface
Soaps do not work with hard water containing calcium and magnesium ions because:
  • $$Ca^{2+} $$ and $$Mg^{2+}$$ ions form insoluble calcium and magnesium salts in the form of scum
  • $$Na^+$$ and $$K^+$$ present in soap react with $$Ca^{2+}$$ and hinder the cleansing process
  • a large amount of soap is to be used in presence of $$Ca^{2+}$$ and $$Mg^{2+}$$
  • scum formed by the combination of $$Na^+, Ca^{2+}$$ and $$Mg^{2+}$$ stick to the cloth and are not removed on agitation
What are the hydrolysis products of glyceryl oleate $$(C_{17}H_{32}COOH)_3C_3H_5$$ during preparation of soap?
  • $$C_6H_{32}COONa + C_3H_5OH$$
  • $$C_{17}H_{32}COOH+CH_3CH_2CH_2OH$$
  • $$C_{17}H_{32}COOH+CH_2OH- CHOH - CH_2OH$$
  • $$C_{17}H_{32}COONa+CH_2OH-CHOH-CH_2OH$$
The role of a catalyst is to change _______.
  • the Gibbs energy of reaction
  • enthalpy of reaction
  • activation energy of reaction
  • equilibrium constant
Dyeing of fibre involves the process of:
  • adsorption
  • absorption
  • sorption
  • all of these
Which of the following metals, adsorb hydrogen on their surface?
  • $$Zn$$
  • $$Pd$$
  • $$Pt$$
  • $$K$$
Entropy change $$(\Delta S)$$ for adsorption:
  • negative
  • positive
  • zero
  • cannot be said
Rate of physisorption decreases with :
  • decrease in temperature
  • increase in temperature
  • decrease in pressure
  • decrease in surface area
Which of the following gases can be adsorbed in more proportion?
  • $$N_{2}$$
  • $$CO_{2}$$
  • $$O_{2}$$
  • $$H_{2}$$
The ease of adsorption of the hydrated alkali metal ions on an ion-exchange resins fallows the order:
  • $${ K }^{ + }\quad <\quad { Na\quad +\quad Rb }^{ + }\quad <\quad { Li }^{ + }$$
  • $${ Na }^{ + }\quad <\quad { { Li }^{ + }\quad +\quad K }^{ + }\quad <\quad { Rb }^{ + }$$
  • $${ Li }^{ + }\quad <\quad { { K }^{ + }\quad +\quad Na }^{ + }\quad <\quad { Rb }^{ + }$$
  • $${ Rb }^{ + }\quad <\quad { { K }^{ + }\quad +\quad Na }^{ + }\quad <\quad { Li }^{ + }$$
During adsorption which of the following is positive?
  • $$\Delta G$$
  • $$T\Delta S$$
  • $$\Delta G + T\Delta S$$
  • none of these
Which of the following is correct about the adsorption of $${N}_{2}$$ over iron? 
  • It is always physically adsorbed
  • Extent of adsorption over iron decreases with the increase in temperature first and then increases
  • It is always chemically adsorbed
  • $${N}_{2}$$ is never adsorbed over iron
The dispersed phase in colloidal iron (III) hydroxide and coltoidal gold is positively and negatively charged, respectively. Which of the following statements is not correct?
  • Sodium sulphate solution causes coagulation in both sols
  • Magnesium chloride solution coagulates, the gold sol more readily than the iron (III) hydroxide sol.
  • the processes of electrophoresis provide charge on both the sols
  • Colloidal iron is coagulated by $$Mg^{+2}$$ and coltoidal gold is coagulated by $$Cl^{-}$$
Which of the following statement regarding a catalyst in an equilibrium| process is correct?
  • It increases the rate of forward reaction only
  • It hastens the easy attainment of equilibrium
  • It increases the activation energy of both the forward and backward process
  • It decreases the rate of backward process
  • It decreases the activation energy of direct process It increases the activation energy of backward process
Bredig's arc method cannot be used for the preparation of colloidal sol of ?
  • Copper
  • Gold
  • Silver
  • Sodium
Which of the following  gases is adsorbed to maximum extent on the given surface?
  • $$NH_3$$
  • $$H_2$$
  • $$N_2$$
  • $$O_2$$
Which metal sol can not be prepared by Bredig's arc method?
  • $$K$$
  • $$Cu$$
  • $$Au$$
  • $$Pt$$
The adsorption of a gas, on a solid surface, varies with pressure of the gas in which of the following manner?
  • Slow fast independent of the pressure
  • Fast slow independent of the pressure
  • Independent of the pressure slow fast
  • Independent of the pressure fast slow
In which condition, adsorption will not take place?
  • When $$\Delta H$$ is negative
  • When $$\Delta H $$ is positive $$\Delta S $$ is positive
  • When $$\Delta H $$ is positive and $$\Delta S $$ is negative
  • When $$\Delta G $$ is negative.
Gold sol is an electronegative sol. The amount of electrolyte required to coagulate a certain amount of gold sol is minimum in the case of:
  • $$CaCl_2$$
  • $$NaCl$$
  • $$AlCl_3$$
  • $$Na_2SO_4$$
Which types of molecules form micelle?
  • non polar molecules
  • polar molecules
  • sufactant molecules
  • Any of the above
Wilkinson catalyst is:
  • $$[(Ph_3P)_3 RhCl]$$ $$(Et = C_2H_5)$$
  • $$[Et_3P)_3IrCl]$$
  • $$[Et_3P)_3RhCl]$$
  • $$[Ph_3P)_3IeCl]$$
Which of the following is not an example of heterogeneous catalytic reaction?
  • Ostwald's process
  • Haber's process
  • Combustion of coal
  • Hydrogenation of vegetable oils
$$CO+H_2$$ $$\xrightarrow[573K/300 atm]{X(catalyst)}$$ $$CH_3OH$$,  the catalyst X is 
  • $$Fe$$
  • $$Cr_2O_3/ZnO$$
  • $$V_2O_5$$
  • $$Al_2O_3$$
Which is the wrong pair?
i) Starch solution           : sol
ii) $$aq.\ NaCl$$                 : true solution
iii) milk                          : emulsion
iv) $$aq.\ BaSO_{4}$$              : true solution
  • $$(i)$$
  • $$(iii)$$
  • $$(iv)$$
  • $$(ii)$$
The reaction
$$2SO_{2}(g)+O_{2} \xrightarrow { NO(g) } 2SO_{3} (g)$$
  • Heterogeneous catalysis
  • Homogegenous catalysis
  • Enzyme catalysis
  • None of them
Lindlar's catlyst is used for conversion of:
  • alkynes to alkenes
  • alkane to alkyne
  • alkyne to alkane
  • alkene to alkyne
The catalyst used in the above conversion is  
1366655_c543307811d44e3cadc7995df423eb26.PNG
  • $$ZnC{l_2}/HCl$$
  • $$AlC{l_3}/HCl$$
  • $$PdC{l_2}/HCl$$
  • $$CuCl/HCl$$
The reaction, $$CO(g) +2H_2(g) \xrightarrow {ZnO/Cr_2O_3}CH_3OH(g)$$ is an example of:
  • homogeneous catalysis
  • heterogeneous catalysis
  • Auto catalysis
  • Enzyme catalysis
If Pt is used as catalyst in the  decomposition of  $$H_{2}SO_{4}$$  then it is an example of: 
  • homogeneous catalysis
  • heterogenous Catalysis
  • negative Catalysis
  • auto Catalysis
Bredig's Arc method can be used to prepare colloidal solution of
  • Au
  • Ag
  • Pt
  • All of the these
Peptization is:
  • Formation of colloid from precipitate
  • Formation of precipitate from colloid
  • Formation of colloid from solution
  • Addition of colloid is solvent.
Following is the variation of physical adsorption with temperature.
Lindlar's catalyst is:
  • $$Pt$$ in ethanol
  • $$Pd + BaSO_{4}$$
  • $$Ni$$ in ethanol
  • $$Na$$ in liquid $$NH_{3}$$
Which one of the following is not a correct statement?
  • Physical adsorption is reversible in nature.
  • Physical adsorption involves Van der Waal's forces.
  • Rate of physical adsorption increases with increase of pressure on the adsorbate.
  • High activation energy is involved in physical adsorption.
In physical adsorption, the forces associated are
  • Ionic bond
  • Covalent bond
  • Van der Waal's forces
  • All of these
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