Water dispersed in solid sulphur

All (a), (b) and (c) are correct

Only for increasing the velocity of the reaction

For altering the velocity of the reaction

Only for decreasing the velocity of the reaction

Does not increase or decrease the free energy change in the reaction

Increases the free energy change in the reaction

Decreases the free energy change in the reaction

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

MCQ Questions for Class 12 Engineering Chemistry Surface Chemistry Quiz 14

In the manufacture of

$H_{2}SO_{4}$ by contact process, the presence of

$As_{2}O_{3}$ acts as

0%
Catalytic promoter
0%
Catalytic poison
0%
Induced catalyst
0%
Auto catalyst

TEL minimizes the knocking effect when mixed with petrol. It acts as

0%
Positive catalyst
0%
Negative catalyst
0%
Auto-catalyst
0%
Induced catalyst

The decomposition of

$H_{2}O_{2}$ may be checked by adding a small quantity of phosphoric acid. It is an example of

0%
Neutralization
0%
Negative catalysis
0%
Positive catalysis
0%
Catalytic poisoning

When freshly precipitated

$Fe(OH)_{3}$ is boiled with water in the presence of few drops of

$dil. HCl$ , a hydrated ferric oxide sol is obtained. The method is termed as:

0%
Electro dispersion
0%
Peptization
0%
Ultra fltration
0%
Dialysis

To coagulate gelatin sol, which of the following is most effective?

0%
$NaCl$
0%
$Na_{3}PO_{4}$
0%
$AlCl_{3}$
0%
$Alcohol$

Which among the following statements is false?

0%
increase of pressure increases the amount of adsorption.
0%
increase of temperature may decrease the amount of adsorption.
0%
the adsorption may be monolayered or multilayered.
0%
particle size of the adsorbent will not affect the amount of adsorption.

Among the following, which is the correct statement about milk?

0%
Milk is an emulsion of liquid fat in water
0%
Milk in emulsion of protein in water
0%
Milk is stabilized by protein
0%
Milk is stabilized by fat

$Fe^{3+}$ ions coagulate blood. This shows that blood contains colloidal particles bearing

0%
negative charge
0%
positive charge
0%
no charge
0%
either positive or negative charge

Butter is a colloid formed when

0%
liquid fat is dispersed in liquid fat
0%
liquid fat is dispersed in water
0%
water is dispersed in liquid fat
0%
solid fat is dispersed in water

Zeolites are used as catalyst in

0%
Petrochemical industries during cracking
0%
In the preparation of $H_{2}SO_{4}$
0%
In the hydrolysis of ester
0%
All

Peptization is a process of

0%
precipitating the colloidal particles.
0%
purifying the colloidal sol.
0%
dispersing the precipitate into colloidal sol.
0%
movement of colloidal particles towards the opposite charged electrodes.

Which is not correct for heterogeneous catalysis?

0%
The catalyst decreases the energy of activation.
0%
The surface of catalyst plays an important role.
0%
The catalyst forms an intermediate with the reactants, at the surface.
0%
There is no change in the energy of activation.

Sulphur sol contains

0%
Discrete sulphur atoms
0%
Discrete sulphur molecules
0%
Water dispersed in solid sulphur
0%
Large aggregates of sulphur molecules

A catalytic poison renders the catalyst ineffective because

0%
it is preferentially adsorbed on the catalyst.
0%
it adsorbs the molecules of the reactants.
0%
it combines chemically with the catalyst.
0%
it combines with one of the reactant.

Which of the following option(s) is/are correct regarding catalytic activity?

0%
Conversion of proteins into amino acids by hydrolysis in intestine is catalysed by enzyme pancreatic trypsin.
0%
In case of fever, the activity of bio-chemical catalyst gets adversely affected.
0%
In heterogeneous catalysis, the reactants must get adsorbed reasonably strong on the catalyst surface but not so strongly that desorption of product becomes impossible.
0%
In the decomposition of methyl urea, enzyme urease acts as a catalyst.

Regarding criteria of catalyst, which one of the following statements is not true?

0%
The catalyst is unchanged chemically after the reaction.
0%
A small quantity of catalyst is often sufficient to bring about a considerable amount of the reaction.
0%
In reversible reaction, the catalyst alters the equilibrium position.
0%
The catalyst alters the rate of reaction.

Which of the following statements is false for catalyst?

0%
A catalyst initiates the reaction.
0%
It does not alter the position of equilibrium in a reversible reaction.
0%
A catalyst remains unchanged in quantity and composition at the end of reaction.
0%
Catalysts are sometimes very specific in respect of a reaction.

Which of the following statements is incorrect about catalyst?

0%
A catalyst catalyses a spontaneous chemical reaction.
0%
A catalyst catalyses all chemical reaction, whether spontaneous or non-spontaneous.
0%
A catalyst provides alternate path of chemical reaction.
0%
A catalyst does not involve in a chemical reaction.

Which of the following is not true with respect to a catalyst?

0%
A catalyst increases the rate of a reaction while inhibitor decreases the reaction rate.
0%
A promoter cannot catalyse the reaction on its own without the presence of a catalyst.
0%
The activity of enzyme catalyst increases in the presence of metal ions like $Mn^{2+}$ , $Co^{2+}$ , etc.
0%
When a solid catalyst is used for gaseous reaction, energy released in physisorption increases the rate of a reaction.

The emulsifying agent in milk is

0%
Lactic acid
0%
Casein
0%
Lactose
0%
Fat

A catalyst is used

0%
Only for increasing the velocity of the reaction
0%
For altering the velocity of the reaction
0%
Only for decreasing the velocity of the reaction
0%
All (a), (b) and (c) are correct

If the absorbate is held on a surface by weak van der Waal's forces the absorption process is called

0%
physical adsorption
0%
chemical adsorption
0%
heat of adsorption
0%
enthalpy of adsorption

Which is the correct statement in case of milk

0%
Milk is an emulsion of protein in water
0%
Milk is an emulsion of fat in water
0%
Milk is stablised by protein
0%
Milk is stabiloised by fat

Which among the following statement is false ?

0%
The adsorption may be monolayered or multilayered
0%
Particle size of adsorbent will not affect the amount of adsorption
0%
Increases of pressure increases amount of adsorption
0%
Increases of temperature may decrease the amount of adsorption

Which of the following forms a colloidal solution ion water?

0%
NaCl
0%
Glucose
0%
Starch
0%
Barium nitrate

A reaction is catalysed by

$'X'$ . Here

$'X'$

0%
Decreases the rate constant of reaction
0%
Does not affect the equilibrium constant of reaction
0%
Decreases the enthalpy of reaction
0%
Decreases the activation energy

When a freshly precipitated substance is converted into a colloidal solution with the help of a third substance, the process is known as

0%
Coagulation
0%
Peptization
0%
Electrodispersion
0%
Dialysis

When

$KClO_{3}$ is heated, it decomposes into

$KCl+O_{2}$ . If some

$MnO_{2}$ is added, the reaction goes much faster because

0%
$MnO_{2}$ decomposes to give $O_{2}$
0%
$MnO_{2}$ provides heat by reacting
0%
Better contact is provided by $MnO_{2}$
0%
$MnO_{2}$ acts as a catalyst

Explanation

$2KClO_{3}\overset{MnO_{2}}{\longrightarrow}2KCl+3O_{2}$

$MnO_2$ acts as a catalyst in the above reaction which enhances the reaction rate.

Colloidal solution cannot be obtained from two such substance which are

0%
Insoluble in each other
0%
In same physical state
0%
In different physical state
0%
None of these

In a reversible reaction, a catalyst will affect the rate of

0%
Forward reaction
0%
Reverse reaction
0%
Forward and reverse reaction
0%
Neither (a) nor (b)

The catalyst used in the lead chamber process of sulphuric acid manufacture is

0%
Platinum
0%
Oxide of nitrogen
0%
Nickel
0%
Vanadium compounds

Explanation

The process of producing sulphuric acid by oxidising sulphur dioxide with moist air, using gaseous nitrogen oxides as catalysts, is known as Lead chamber process. This reaction takes place primarily in a series of large, box-like chambers of sheet lead.

$2SO_{2}+O_{2}\ \overset{NO}{\rightarrow}\ 2SO_{3}$

What is the role of a catalyst in a catalysed reaction?

0%
Lowers the activation energy
0%
Increases the activation energy
0%
Affects the free energy change
0%
Affects the enthalpy change

The role of a catalyst in a reversible reaction is to

0%
Increase the rate of forward reaction
0%
Decrease the rate of backward reaction
0%
Alter the equilibrium constant of the reaction
0%
Allow the equilibrium to be achieved quickly

In the following reaction the catalyst used is

0%
$Al_{2}O_{3}$
0%
$Cr_{2}O_{3}$
0%
$Cr_{2}O_{3}$ and $Al_{2}O_{3}$
0%
Zn dust

Which of the following reactions leads to the formation of a substance in the colloidal state

0%
$Cu+HgCl_{2}\rightarrow CuCl_{2}+Hg$
0%
$2HNO_{3}+3H_{2}S\rightarrow 3S+4H_{2}O+2NO$
0%
$2Mg+CO_{2}\rightarrow 2MgO+C$
0%
$Cu+CuCl_{2}\rightarrow Cu_{2}Cl_{2}$

Explanation

$2HNO_{3}+3H_{2}S\rightarrow \underset{sol}{3S}+4H_{2}O+2NO_{2}$

Sulphur sol contains large aggregates of sulphur molecules such that the size of aggregate come in colloidal range.

When a catalyst is added to a system the

0%
Value of equilibrium constant is decreased
0%
The rate of forward reaction is increased and that of backward reaction is decreased
0%
Equilibrium concentration are unchanged
0%
Equilibrium concentration are increased

Which of the following is used as a catalyst in the manufacture of toluene from benzene with

$CH_{3}Cl?$

0%
Ni
0%
Anhydrous $AlCl_{3}$
0%
Pd
0%
Pt

Explanation

$C_{6}H_{6}+CH_{3}Cl\xrightarrow[AlCl_{3}]{Anhydrous}C_{6}H_{5}CH_{3}+HCl$

Anhydrous

$AlCl_{3}$ is used as shown in the reaction above.

A catalyst

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

Hydrolysis ethyl acetate is catalysed by aqueous

0%
$Na_{2}SO_{4}$
0%
$K_{2}SO_{4}$
0%
$H_{2}SO_{4}$
0%
$BaSO_{4}$

Explanation

$CH_{3}CHOOC_{2}H_{5}+HOH\xrightarrow[catalyst]{conc.\ H_{2}SO_{4}}CH_{3}COOH+C_{2}H_{5}OH$

$H_{2}SO_{4}$ is used as a catalyst in hydrolysis ethyl acetate.

In which of the following reactions heterogeneous catalysis is involved?

(a) $2 SO_{2}(g)+O_{2}(g) \quad \stackrel{NO(g)}{\longrightarrow} 2 SO_{3}(g)$

(b) $2 S O_{2}(g) \stackrel{Pt(s)}{\longleftarrow} 2 S O_{3}(g)$

(d) $C H_{3} C O O C H_{3}(l)+H_{2} O(l) \stackrel{H Cl}{\longrightarrow} C H_{3} C O O H(a q)+C H_{3} O H(a q)$

0%
(b),(c)
0%
(b),(c),(d)
0%
(a), (b), (c)
0%
(d)

Which of the following statements are correct about solid catalyst?

0%
Same reactants may give different product by using different catalysts.
0%
Catalyst does not change $\Delta \mathrm{H}$ of reaction.
0%
Catalyst is required in large quantities to catalyse reactions.
0%
Catalytic activity of a solid catalyst does not depend upon the strength of chemisorption.

Shape selective catalysis is that reaction which s catalysed :

0%
By enzyme
0%
by zeolite
0%
by platinum
0%
by Zeigler - Natta Catalyst

The method pf blood purification in human body is :

0%
Electrophoresis
0%
Electric osmosis
0%
Dialysis
0%
Coagulation

Bredigs arc method involves:

0%
dispersion of metal
0%
condensation of metal
0%
dispersion as well as condensation
0%
neither dispersion nor condensation

Which of the following is an example of aerosol?

0%
Paint
0%
Milk
0%
Sponge
0%
Cloud

Which of the following statement is not correct?

0%
Physical adsorption is due to Vander Waal's forces
0%
Physical adsorption is irreversible
0%
Chemical adsorption increases with increase in temperature in temperature up to certain limit than decreases
0%
Enthalpy of adsorption (|ΔH|) for a chemical adsorption is greater than that of physical adsorption

On adding

$AgNO_{3}$ solution to

$KI$ solution, a negatively charged collodial sol will be formed in which of the following conditions?

0%
$100\ mL$ of $0.1\ M\ AgNO_{3}+100\ mL$ of $0.1\ M\ KI$
0%
$100\ mL$ of $0.1\ M\ AgNO_{3}+50\ mL$ of $0.2\ M\ KI$
0%
$100\ mL$ of $0.2\ M\ AgNO_{3}+100\ mL$ of $0.1\ M\ KI$
0%
$100\ mL$ of $0.1\ M\ AgNO_{3}+100\ mL$ of $0.15\ M\ KI$

Which of the following statement is not true about the oil-in-water type emulsion ?

0%
Addition of small amount of water, no separate layer of water is formed
0%
Addition of a small amount of oil soluble dye renders the entire emulsion coloured
0%
Addition of oil results in the formation of two layers
0%
Addition of a small amount of an electrolyte increases the conductivity of the emulsion

Chromatography is based on :

0%
Physical adsorption
0%
Chemical adsorption
0%
Hydrogen bond
0%
Adsorption

Peptization involves:

0%
precipitation of colloidal particles
0%
disintegration of colloidal aggregates
0%
purification of colloids
0%
impact of molecules of the dispersion medium on the colloidal particles

CBSE Questions for Class 12 Engineering Chemistry Surface Chemistry Quiz 14 - 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 14 - MCQExams.com

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

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