CBSE Questions for Class 12 Engineering Chemistry Surface Chemistry Quiz 13 - MCQExams.com

The most suitable reagent for  given conversion is 
1601375_03eae7c3ab3142a2b33869068bd9fce6.PNG
  • Diimide
  • $$H_{2}/Ni_{2}B$$
  • $$Zn/dil.HCl$$
  • $$LiAlH_{4}$$
In which name reaction incorrect regents is/ are given?
  • HVZ reaction $$\rightarrow $$ Red phosphorous $$+{Cl}_{2}$$
  • Etard reaction $$\rightarrow Cr{O}_{2}{Cl}_{2}+{CS}_{2}$$
  • Hofmann degradation reaction $$\rightarrow {Br}_{2}+KOH$$
  • Perkin reaction $$\rightarrow {({CH}_{3}CO)}_{2}O+{CH}_{3}COONa$$
  • Finkelstein reaction $$\rightarrow SO{Cl}_{2}+$$ pyridine
The phrase 'hot dilute soup', was used by
  • Oparin
  • Darwin
  • Haldane
  • None of these
Which is a characteristic of a catalyst?
  • It changes the equilibrium point
  • It initiates the reaction
  • It alters the rate of reaction
  • It increases the average kinetic energy of the molecule
The volume of gases $${ H }_{ 2 },\ { CH }_{ 4 },\ { CO }_{ 2 }$$, and $${ NH }_{ 3 }$$ adsorbed by $$1 g $$ of charcoal at $$288K$$ are in the order:
  • $${ H }_{ 2 }> { CH }_{ 4 } > { CO }_{ 2 } > { NH }_{ 3 }$$
  • $${ CH }_{ 2 }> { CO }_{ 2 } > { NH }_{ 3 } > { H }_{ 2 }$$
  • $${ CO }_{ 2}>{ NH }_{ 3 } > { H }_{ 2 } > { CH }_{ 4 }$$
  • $${ NH }_{ 3 }> { CO }_{ 2 }>{ CH }_{ 4 } > { H }_{ 2 }$$
Consider the following boxes Fog, mist, sponge, clouds, pumice. The total number of aerosols is
  • Two
  • Three
  • Four
  • Five
The nature of colloidal solution of methylene blue and haemoglobin is _______ and ________ respectively.
  • positive, positive
  • negative, negative
  • positive, negative
  • negative, positive
When $$ AgNO_3 (aq) $$ reacts with excess of iodine, we get :
  • $$ AgI$$
  • $$ HIO_3 $$
  • $$ AgO$$
  • $$HI $$
$$ NH_3 $$ is absorbed by:
  • Ozone
  • CaO
  • Pyrgallol
  • $$ CaCl_2 $$
In a homogenous catalyst 
  • The catalyst and the reactants should be gases
  • The catalyst and the reactants should from a single phase
  • Catalyst and the reactants are all solids
  • The catalyst and the reactions are all liquids
Adam's catalyst is
  • Platinum
  • Iron
  • Molybdenum
  • Nickel
A solution is prepared by addition of excess of $$AgNO_3$$ solution in KI solution. The charge likely to develop on colloidal particles is?
  • Positive
  • Negative
  • No charge
  • Both charges
In Bredig's arc method some alkali is added 
  • To increase the conductance
  • To coagulate the sol formed
  • As a peptizing agent
  • To stabilize the sol
The catalyst used in Deacon's process is 
  • $$ CuCl_2 $$
  • $$ Cu $$
  • $$ CuSO_4 $$
  • $$ CuS $$

Arrange the following diagrams in correct sequences of steps involved in the mechanism of catalyst, in accordance with modern adsorption theory.
1390147_adbb743044c8438393720bcdfee6d3fe.png
  • $$I\rightarrow III\rightarrow II\rightarrow IV\rightarrow V$$
  • $$I\rightarrow II \rightarrow III\rightarrow V\rightarrow IV$$
  • $$I\rightarrow II\rightarrow III\rightarrow IV\rightarrow V$$
  • $$I\rightarrow III\rightarrow II\rightarrow V\rightarrow IV$$
$$As_{2}O_{3}+3H_{2}S\rightarrow As_{2}S_{3}(sol)+3H_{2}O$$, the principle involved in the preparation of above coolloidal solution:
  • Oxidation
  • Reduction
  • Double displacement
  • Hydrolysis
Colloidal solution of arsenious sulphide can be prepared by:
  • Electro-dispersion method
  • Peptization
  • Double decomposition
  • Hydrolysis
Rate of adsorption of gas is greater when pressure increased 
  • For low range of pressure
  • For high range of pressure
  • For moderate range of pressure
  • For every range of pressure
 The correct match between item $$I$$ and item $$II$$ is:

Item -I                            Item-II                       
A. BenzaldehydeP. Adsorbate
B. AluminaQ. Mobile phase
C. AcetonitrileR. Adsorbent
 
  • $$A \rightarrow Q; B \rightarrow R; C \rightarrow P$$
  • $$A \rightarrow P; B \rightarrow R; C \rightarrow Q$$
  • $$A \rightarrow Q; B \rightarrow P; C \rightarrow R$$
  • $$A \rightarrow R; B \rightarrow Q; C \rightarrow P$$
Which of the following is the emulsifying agent for both $$O/W$$ type and $$W/O$$ of emulsions
  • Soap
  • Graphite
  • Proteins
  • Both $$1$$ & $$2$$
Which of the following statements is incorrect regarding physiosrption?
  • More easily liquefiable gases adsorb readily.
  • Under high pressure, it results into multimolecular layer on adsorbent surface.
  • Enthalpy of adsorption ( $$\triangle { H }_{ adsorption }$$ ) is low and positive.
  • It occurs because of Van der Waal's forces.
Which of the following absorbs carbon dioxide?
  • $$KOH$$
  • $$Ca{ Cl }_{ 2 }$$
  • $$Cu{ SO }_{ 4 }$$
  • All of the above
An example of a positively charged sol is:
  • $$CdS$$ sol
  • Starch sol
  • Haemoglobin
  • Gold sol
Peptizing agent is 
  • Always an Electrolyte
  • Always a Non - electrolyte
  • Electrolyte or Non - electrolyte
  • A lyophilic colloid
Which of the following is an example of heterogeneous catalysis? 
  • Production of ammonia by Haber's process
  • Oxidation of $$SO_{2}$$ in to $$SO_{3}$$ during contact process
  • Method of obtaining methanol from water gas
  • All of the given
Which is not the correct statement for a catalyst ? 
  • It does not alter $$E_{ a }\quad $$
  • The surface of a catalyst adsorbs reactants
  • Catalyst may form intermediates with reactants
  • Action of enzyme catalyst is always specific
How are the following formed? 
  • fog
  • mist
  • dew
  • forst.
Which of the following statements are true about $$AgI$$ sol prepared by peptization of $$AgI$$ with $$ AgNO_3 $$ (excess)?
  • in electrophoresis, the dispersed phase will move towards cathode
  • $$ AlCl_3 $$ is more effective than $$ Na_3PO_4 $$ for bringing about coagulation of sol
  • $$ Na_3PO_4$$ is more effective than $$ AlCl_3 $$ for bringing about coagulation of sol
  • On persistent dialysis of a sol, precipitation of colloidal sol takes place (coagulation)
Which one of the following is not explained by adsorption? 
  • When acetic acid solution is shaken with charcoal, the concentration of the acid decreases
  • The white precipitate of $$Mg(OH_2)$$ attains blue colour when precipitated in the presence of magneson reagent
  • The air becomes dry in the presence of silica gel
  • An aqueous solution of NaOH attains pink colour with a drop of phenolphthalein
Adsorption is:
  • An exothermic process so increases with a decrease in temperature
  • An endothermic process so decreases with an increase in temperature
  • An exothermic process so decreases with an increase in temperature
  • None
What is relationship between 
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  • Diasteromer
  • Enantiomer
  • Conformer
  • None of these
Which one of the following is an example of homogeneous catalysis?
  • Ostwald's process (manufacture of $$HNO_3$$)
  • Lead chamber process (manufacture of $$H_2SO_4$$)
  • Haber's process (manufacture of $$NH_3$$)
  • Contact process (mnufacture of $$H_2SO_4$$)
Which of the following is used to cure kalaazar
  • Argyrol
  • Colloidal antimony
  • Colloidal gold
  • Colloidal palladium
Which of the following reaction is used to prepare colloidal sol by double decomposition?
  • $$As_{2}O_{3} + 3H_{2}S\rightarrow As_{2}S_{3} + 3H_{2}O$$
  • $$2AuCl_{3}+3HCHO + 3H_{2}O \rightarrow 2Au + 3HCOOH + 6HCl$$
  • $$SO_{2} + 2H_{2}S \rightarrow 3S + 2H_{2}O$$
  • $$FeCl_{3} + 3H_{2}O \rightarrow Fe(OH)_{3} + 3HCl$$
Which reagent, when mixed with ammonium sulfate and then heated, liberates ammonia?
  • aqueous bromine
  • dilute hydrochloric acid
  • limewater
  • potassium dichormate (VI) in acidic solution
When a chalk stick is dipped in ink, then
  • the colored pigments in the ink get absorbed in the chalk.
  • the solvent get adsorbed at the surface of chalk.
  • inside of the chalk will remain as white while the surface will have colored pigments.
  • inside of the chalk will have colored pigments while the surface will remain white.
Chromatography is a technique based on:
  • Solubilities of solute
  • Adsorption of solute
  • Chemical adsorption followed by dispersion
  • Differential adsorption of different constituents of a mixture
Sorption is the term used when
  • only adsorption takes place
  • only absorption takes place
  • adsorption and absorption occur simultaneously
  • desorption takes place
Which of the following interface can never be obtained?
  • Liquid-liquid
  • Solid-solid
  • Liquid-gas
  • Gas-gas
Which characteristic of adsorption is wrong?
  • Physical adsorption decreases with increase in temperature.
  • Physical adsorption increases with increase in temperature.
  • Physical adsorption is a reversible process.
  • Adsorption is limited only to the surface.
Physical adsorption is appreciable at
  • Higher temperature
  • Lower temperature
  • At room temperature
  • $$100^{\circ}C$$
Which of the following is not considered as adsorption?
  • Extraction of noble gases by charcoal
  • Sponge placed in water
  • Finely divided charcoal stirred in dilute acetic acid
  • Decolourisation of sugar by animal charcoal
For the conversion of oxygen to ozone in the atmosphere, nitric oxide in gaseous phase acts as:
  • enzyme catalyst
  • inhibitor
  • homogeneous catalyst
  • heterogeneous catalyst
The enthalpy of adsorption in physisorption lies in the range
  • $$- (40 - 400) kJ/mol$$
  • $$- (80 - 240) kJ/mol$$
  • $$- (20 - 40) kJ/mol$$
  • $$- (1 - 10) kJ/mol$$
Platinized asbestos is used as a catalyst in the manufacture of $$H_{2}SO_{4}$$. It is an example of
  • Homogeneous catalyst
  • Heterogeneous catalyst
  • Auto-catalyst
  • Induced catalyst
Which one of the following characteristics is not correct for physical adsorption of a gas on solid?
  • Adsorption is reversible.
  • Adsorption increase with increase in temperature.
  • Absorption is spontaneous.
  • Both enthalpy and entropy of adsorption are negative.
The catalyst used in the manufacture of hydrogen by Bosch's process is
  • $$Fe_{2}O_{3}$$
  • $$Cr_{2}O_{3}$$
  • $$Fe_{2}O_{3} + Cr_{2}O_{3}$$
  • $$Cu$$
Which one of the following is not the example of homogeneous catalysis?
  • Formation of $$SO_{3}$$ in the chamber process
  • Formation of $$SO_{3}$$ in the contact process
  • Hydrolysis of an ester in presence of acid
  • Decomposition of $$KClO_{3}$$ in the presence of $$MnO_{2}$$
In a reversible reaction, a catalyst
  • increases the rate of forward reaction only.
  • increases the rate of forward reaction to a greater extent that of the back-ward reaction.
  • increases the rate of forward reaction and decreases that of the backward reaction.
  • increases the rate of forward and backward reaction by the same factor.
A catalyst
  • Increases the free energy change in the reaction.
  • Decrease the free energy change in the reaction.
  • Does not increase and decreases the free energy change in the reaction.
  • Can either decrease or increase the free energy change depending on what catalyst we use.
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