The correct match between item $$I$$ and item $$II$$ is: Item -I Item-II A. Benzaldehyde P. Adsorbate B. Alumina Q. Mobile phase C. Acetonitrile R. Adsorbent

$$A \rightarrow P; B \rightarrow R; C \rightarrow Q$$

$$A \rightarrow Q; B \rightarrow R; C \rightarrow P$$

$$A \rightarrow Q; B \rightarrow P; C \rightarrow R$$

$$A \rightarrow R; B \rightarrow Q; C \rightarrow P$$

Electrolyte or Non - electrolyte

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

Does not increase and decreases the free energy change in the reaction.

Increases the free energy change in the reaction.

Decrease the free energy change in the reaction.

Can either decrease or increase the free energy change depending on what catalyst we use.

MCQ Questions for Class 12 Engineering Chemistry Surface Chemistry Quiz 13

The most suitable reagent for given conversion is

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Diimide
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$H_{2}/Ni_{2}B$
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$Zn/dil.HCl$
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$LiAlH_{4}$

In which name reaction incorrect regents is/ are given?

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HVZ reaction $\rightarrow$ Red phosphorous $+{Cl}_{2}$
0%
Etard reaction $\rightarrow Cr{O}_{2}{Cl}_{2}+{CS}_{2}$
0%
Hofmann degradation reaction $\rightarrow {Br}_{2}+KOH$
0%
Perkin reaction $\rightarrow {({CH}_{3}CO)}_{2}O+{CH}_{3}COONa$
0%
Finkelstein reaction $\rightarrow SO{Cl}_{2}+$ pyridine

The phrase 'hot dilute soup', was used by

0%
Oparin
0%
Darwin
0%
Haldane
0%
None of these

Which is a characteristic of a catalyst?

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It changes the equilibrium point
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It initiates the reaction
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It alters the rate of reaction
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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:

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${ H }_{ 2 }> { CH }_{ 4 } > { CO }_{ 2 } > { NH }_{ 3 }$
0%
${ CH }_{ 2 }> { CO }_{ 2 } > { NH }_{ 3 } > { H }_{ 2 }$
0%
${ CO }_{ 2}>{ NH }_{ 3 } > { H }_{ 2 } > { CH }_{ 4 }$
0%
${ NH }_{ 3 }> { CO }_{ 2 }>{ CH }_{ 4 } > { H }_{ 2 }$

Explanation

The amount of gas adsorbed by a solid depends on the nature of the gas. In general, easily liquefiable gases having higher critical temperatures are easily adsorbed because they have strong van der Waal's forces.

The increasing order of critical temperature is $NH_3>CO_2>CH_4>H_2$

The volume of gases $H_2, CH_4, CO_2, NH_3$ adsorbed by 1g of charcoal at 288K are in the order: $NH_3>CO_2>CH_4>H_2$ .

Hence option D is correct.

Consider the following boxes Fog, mist, sponge, clouds, pumice. The total number of aerosols is

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Two
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Three
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Four
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Five

The nature of colloidal solution of methylene blue and haemoglobin is _______ and ________ respectively.

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positive, positive
0%
negative, negative
0%
positive, negative
0%
negative, positive

Explanation

The nature of colloidal solution depends upon the charge on particles of the dispersed phase and on the basis of that they are classified into positively or negatively charged.

Hemoglobin and methylene blue both are positively charged colloidal solutions.

Hence, option

$A$ is correct.

When

$AgNO_3 (aq)$ reacts with excess of iodine, we get :

0%
$AgI$
0%
$HIO_3$
0%
$AgO$
0%
$HI$

$NH_3$ is absorbed by:

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Ozone
0%
CaO
0%
Pyrgallol
0%
$CaCl_2$

In a homogenous catalyst

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The catalyst and the reactants should be gases
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The catalyst and the reactants should from a single phase
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Catalyst and the reactants are all solids
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The catalyst and the reactions are all liquids

Adam's catalyst is

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Platinum
0%
Iron
0%
Molybdenum
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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?

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Positive
0%
Negative
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No charge
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Both charges

Explanation

$AgNO_{3}$ solution is added to KI solution, negatively charged sol of AgI is formed. This is due to selective adsorption of

$I^{-}$ ion from the dispersion medium.

$AgI + I^{-} ----> [AgI]I^{-}$

In Bredig's arc method some alkali is added

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To increase the conductance
0%
To coagulate the sol formed
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As a peptizing agent
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To stabilize the sol

The catalyst used in Deacon's process is

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$CuCl_2$
0%
$Cu$
0%
$CuSO_4$
0%
$CuS$

Arrange the following diagrams in correct sequences of steps involved in the mechanism of catalyst, in accordance with modern adsorption theory.

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$I\rightarrow III\rightarrow II\rightarrow IV\rightarrow V$
0%
$I\rightarrow II \rightarrow III\rightarrow V\rightarrow IV$
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$I\rightarrow II\rightarrow III\rightarrow IV\rightarrow V$
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$I\rightarrow III\rightarrow II\rightarrow V\rightarrow IV$

$As_{2}O_{3}+3H_{2}S\rightarrow As_{2}S_{3}(sol)+3H_{2}O$ , the principle involved in the preparation of above coolloidal solution:

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Oxidation
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Reduction
0%
Double displacement
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Hydrolysis

Colloidal solution of arsenious sulphide can be prepared by:

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Electro-dispersion method
0%
Peptization
0%
Double decomposition
0%
Hydrolysis

Rate of adsorption of gas is greater when pressure increased

0%
For low range of pressure
0%
For high range of pressure
0%
For moderate range of pressure
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For every range of pressure

The correct match between item

$I$ and item

$II$ is:

Item -I	Item-II
A. Benzaldehyde	P. Adsorbate
B. Alumina	Q. Mobile phase
C. Acetonitrile	R. Adsorbent

0%
$A \rightarrow Q; B \rightarrow R; C \rightarrow P$
0%
$A \rightarrow P; B \rightarrow R; C \rightarrow Q$
0%
$A \rightarrow Q; B \rightarrow P; C \rightarrow R$
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$A \rightarrow R; B \rightarrow Q; C \rightarrow P$

Which of the following is the emulsifying agent for both

$O/W$ type and

$W/O$ of emulsions

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Soap
0%
Graphite
0%
Proteins
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Both $1$ & $2$

Which of the following statements is incorrect regarding physiosrption?

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More easily liquefiable gases adsorb readily.
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Under high pressure, it results into multimolecular layer on adsorbent surface.
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Enthalpy of adsorption ( $\triangle { H }_{ adsorption }$ ) is low and positive.
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It occurs because of Van der Waal's forces.

Which of the following absorbs carbon dioxide?

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$KOH$
0%
$Ca{ Cl }_{ 2 }$
0%
$Cu{ SO }_{ 4 }$
0%
All of the above

An example of a positively charged sol is:

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$CdS$ sol
0%
Starch sol
0%
Haemoglobin
0%
Gold sol

Peptizing agent is

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Always an Electrolyte
0%
Always a Non - electrolyte
0%
Electrolyte or Non - electrolyte
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A lyophilic colloid

Which of the following is an example of heterogeneous catalysis?

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Production of ammonia by Haber's process
0%
Oxidation of $SO_{2}$ in to $SO_{3}$ during contact process
0%
Method of obtaining methanol from water gas
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All of the given

Explanation

Hint: In Heterogeneous catalysis, the reactants and catalysts are in different phases.

Step 1: Heterogeneous Catalysis

Catalyst is a substance that affects the rate of a reaction (increasing and decreasing without changing its chemical nature) and after the reaction remains unchanged.
The process of affecting the rate of a reaction by using a catalyst is called Catalysis.
When the reactants (usually in the gas phase) and catalyst (usually in the solid phase) are in different phases, the process is called Heterogeneous catalysis.
The rate of heterogeneous catalysis is directly proportional to the surface area of the catalyst.

Step 2: Explanation
In, Option (A), In the production of ammonia by Haber's process-

$N_2(g)+3H_2(g) \xrightarrow{Fe(s)}2NH3(g)$

$N_2$ and

$H_2$ reactants are in gaseous phase while

$Fe$ is in solid phase.So, this reaction represents heterogeneous catalysis.

In Option (B), In the oxidation of

$SO_2$ in to

$SO_3$ during contact process

$2SO_2(g) \xrightarrow{Pt(s)}2SO_3(g)$

the reactant

$SO_2$ and product

$SO_3$ are in gaseous phase while Platinum is in solid phase.

In Option (C), In the method of obtaining

$methanol$ from

$water\ gas$ -

$[CO + H_2](g) + H_2(g) \xrightarrow{ZnO + Cr_2O_3} CH_3OH(g)$

Here also, the reactants are in gas phase and the catalyst are in solid phase.

So all the three options are correct as they all are the examples of heterogeneous catalysis.

Final Step: Correct answer - (D) All of the given.

Which is not the correct statement for a catalyst ?

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It does not alter $E_{ a }\quad$
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The surface of a catalyst adsorbs reactants
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Catalyst may form intermediates with reactants
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Action of enzyme catalyst is always specific

How are the following formed?

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fog
0%
mist
0%
dew
0%
forst.

Which of the following statements are true about

$AgI$ sol prepared by peptization of

$AgI$ with

$AgNO_3$ (excess)?

0%
in electrophoresis, the dispersed phase will move towards cathode
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$AlCl_3$ is more effective than $Na_3PO_4$ for bringing about coagulation of sol
0%
$Na_3PO_4$ is more effective than $AlCl_3$ for bringing about coagulation of sol
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On persistent dialysis of a sol, precipitation of colloidal sol takes place (coagulation)

Which one of the following is not explained by adsorption?

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When acetic acid solution is shaken with charcoal, the concentration of the acid decreases
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The white precipitate of $Mg(OH_2)$ attains blue colour when precipitated in the presence of magneson reagent
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The air becomes dry in the presence of silica gel
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An aqueous solution of NaOH attains pink colour with a drop of phenolphthalein

Adsorption is:

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An exothermic process so increases with a decrease in temperature
0%

An endothermic process so decreases with an increase in temperature
0%
An exothermic process so decreases with an increase in temperature
0%
None

What is relationship between

0%
Diasteromer
0%
Enantiomer
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Conformer
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None of these

Which one of the following is an example of homogeneous catalysis?

0%
Ostwald's process (manufacture of $HNO_3$ )
0%
Lead chamber process (manufacture of $H_2SO_4$ )
0%
Haber's process (manufacture of $NH_3$ )
0%
Contact process (mnufacture of $H_2SO_4$ )

Explanation

Hint: Those reactions in which the catalyst exists in the same phase as reactants is called homogeneous catalysis.

Step 1: Ostwald’s Process:

In Ostwald’s process ammonia gas reacts with oxygen in the presence of platinum as a catalyst to produce nitric acid. Ammonia and oxygen both reactants are present in the gaseous phase but platinum is present in the solid phase. Thus the reactants and catalysts are present in different phases so it is an example of heterogeneous catalysis

Step 2: Lead chamber process :

In the Lead chamber process sulfuric acid is produced by oxidizing sulfur dioxide with moist air in the presence of nitrogen oxide as a catalyst. So here $SO_2$ is present in the gaseous phase and $NO$ is also present in the gas phase. Thus the reactants and catalysts are present in the same phase so it is an example of homogeneous catalysis

Step 3: Haber's process :

In Haber’s process nitrogen gas reacts with hydrogen gas in the presence of iron as a catalyst to produce ammonia. So here nitrogen and hydrogen both reactants are present in the gaseous phase but iron is present in the solid phase. Thus the reactants and catalysts are present in different phases so it is an example of heterogeneous catalysis.

Step 4: Contact process

In the Contact process, $H_2SO_4$ acid is produced by the reaction of sulphur dioxide in the presence of $V_2O_5$ as the catalyst. So here Sulphur dioxide is present in the gaseous phase and $V_2O_5$ is present in the solid phase. Thus the reactants and catalysts are present in different phases so it is an example of heterogeneous catalysis.

Final Step: Correct option is (B)-Lead Chamber process.

Which of the following is used to cure kalaazar

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Argyrol
0%
Colloidal antimony
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Colloidal gold
0%
Colloidal palladium

Which of the following reaction is used to prepare colloidal sol by double decomposition?

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$As_{2}O_{3} + 3H_{2}S\rightarrow As_{2}S_{3} + 3H_{2}O$
0%
$2AuCl_{3}+3HCHO + 3H_{2}O \rightarrow 2Au + 3HCOOH + 6HCl$
0%
$SO_{2} + 2H_{2}S \rightarrow 3S + 2H_{2}O$
0%
$FeCl_{3} + 3H_{2}O \rightarrow Fe(OH)_{3} + 3HCl$

Which reagent, when mixed with ammonium sulfate and then heated, liberates ammonia?

0%
aqueous bromine
0%
dilute hydrochloric acid
0%
limewater
0%
potassium dichormate (VI) in acidic solution

Explanation

Test for the ammonium ion is adding a base then warming and then ammonia gas is produced therefore answer is C because limewater is

$Ca(OH)_2$ which is a base and when it reacts with an ammonium ion which ammonium sulphate it produces ammonia gas overall reaction is:

$Ca(OH)_2 + (NH_4)_2SO_4 \rightarrow CaSO_4 + 2NH_3 + 2H_2O$

When a chalk stick is dipped in ink, then

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the colored pigments in the ink get absorbed in the chalk.
0%
the solvent get adsorbed at the surface of chalk.
0%
inside of the chalk will remain as white while the surface will have colored pigments.
0%
inside of the chalk will have colored pigments while the surface will remain white.

Chromatography is a technique based on:

0%
Solubilities of solute
0%
Adsorption of solute
0%
Chemical adsorption followed by dispersion
0%
Differential adsorption of different constituents of a mixture

Sorption is the term used when

0%
only adsorption takes place
0%
only absorption takes place
0%
adsorption and absorption occur simultaneously
0%
desorption takes place

Which of the following interface can never be obtained?

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Liquid-liquid
0%
Solid-solid
0%
Liquid-gas
0%
Gas-gas

Which characteristic of adsorption is wrong?

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Physical adsorption decreases with increase in temperature.
0%
Physical adsorption increases with increase in temperature.
0%
Physical adsorption is a reversible process.
0%
Adsorption is limited only to the surface.

Physical adsorption is appreciable at

0%
Higher temperature
0%
Lower temperature
0%
At room temperature
0%
$100^{\circ}C$

Which of the following is not considered as adsorption?

0%
Extraction of noble gases by charcoal
0%
Sponge placed in water
0%
Finely divided charcoal stirred in dilute acetic acid
0%
Decolourisation of sugar by animal charcoal

For the conversion of oxygen to ozone in the atmosphere, nitric oxide in gaseous phase acts as:

0%
enzyme catalyst
0%
inhibitor
0%
homogeneous catalyst
0%
heterogeneous catalyst

Explanation

When the reactants, products and the catalyst are in the same phase (i.e., liquid or gas), the process is said to be homogeneous catalysis.

Since oxygen and nitric oxide are both in the gas phase, so nitric oxide acts as a homogeneous catalyst.

Hence, option

$C$ is correct.

The enthalpy of adsorption in physisorption lies in the range

0%
$- (40 - 400) kJ/mol$
0%
$- (80 - 240) kJ/mol$
0%
$- (20 - 40) kJ/mol$
0%
$- (1 - 10) kJ/mol$

Platinized asbestos is used as a catalyst in the manufacture of

$H_{2}SO_{4}$ . It is an example of

0%
Homogeneous catalyst
0%
Heterogeneous catalyst
0%
Auto-catalyst
0%
Induced catalyst

Which one of the following characteristics is not correct for physical adsorption of a gas on solid?

0%
Adsorption is reversible.
0%
Adsorption increase with increase in temperature.
0%
Absorption is spontaneous.
0%
Both enthalpy and entropy of adsorption are negative.

The catalyst used in the manufacture of hydrogen by Bosch's process is

0%
$Fe_{2}O_{3}$
0%
$Cr_{2}O_{3}$
0%
$Fe_{2}O_{3} + Cr_{2}O_{3}$
0%
$Cu$

Which one of the following is not the example of homogeneous catalysis?

0%
Formation of $SO_{3}$ in the chamber process
0%
Formation of $SO_{3}$ in the contact process
0%
Hydrolysis of an ester in presence of acid
0%
Decomposition of $KClO_{3}$ in the presence of $MnO_{2}$

Explanation

Hint: A homogenous catalysis is a form of catalysis in which the physical state of reactants and catalysts is similar.

Correct Answer: Option B

Explanation of Correct Option:

The reaction of formation of $SO_3$ in the contact process is as follows:

$2SO_2(g)+O_2(g)\ \underrightarrow{_{V_2O_5(s)}} \ 2SO_3$

Here, $SO_2$ and $O_2$ are in gaseous state and catalyst $V_2O_5$ is in solid form.
Thus, the formation of $SO_3$ in the contact process is not an example of homogenous catalysis.

Explanation of Incorrect Option:

The reaction of formation of $SO_3$ in the chamber process is as follows:

$2SO_2(g)+O_2(g)\ \underrightarrow{_{NO(g)}} \ 2SO_3$

Here,

$SO_2, O_2$ and catalyst

$NO$ are present in same physical state i.e., gaseous state.
Thus, the formation of

$SO_3$ in the chamber process is an example of homogenous catalysis.

The reaction of hydrolysis of an ester in presence of acid is as follows:

$CH_3COOC_2H_5(l) + H_2O(l) \ \ \underrightarrow {_{H_2SO_4(l)}} \ \ CH_3COOH + C_2H_5OH$

Here, reactants and catalyst all are in the same physical state i.e., liquid.

Thus, the hydrolysis of an ester in presence of acid is an example of homogenous catalysis.

The reaction of decomposition of $KClO_3$ in the presence of $MnO_2$ is as follows:

$2KClO_3(s) \ \ \underrightarrow {_{MnO_2(s)}} \ \ 2KCl + 3O_2$

Here, reactants and catalyst all are in the same physical state i.e., solid.

Thus, decomposition of

$KClO_3$ in the presence of

$MnO_2$ is an example of homogenous catalysis.

In a reversible reaction, a catalyst

0%
increases the rate of forward reaction only.
0%
increases the rate of forward reaction to a greater extent that of the back-ward reaction.
0%
increases the rate of forward reaction and decreases that of the backward reaction.
0%
increases the rate of forward and backward reaction by the same factor.

A catalyst

0%
Increases the free energy change in the reaction.
0%
Decrease the free energy change in the reaction.
0%
Does not increase and decreases the free energy change in the reaction.
0%
Can either decrease or increase the free energy change depending on what catalyst we use.

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

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

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

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

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