8247 + Mcqs in Chemical Engineering Page 22 McqOptions

1051.	Bituminous coal
A.	ignites less easily than anthracite.
B.	is generally coking.
C.	burns with smoky yellow flame.
D.	both (b) and (c).
Answer» E.

Discussion

1052.	Combustion reaction of fuels is a/an __________ reaction.
A.	auto catalytic
B.	exothermic
C.	endothermic
D.	none of these
Answer» C. endothermic

Discussion

1053.	Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its
A.	caking index.
B.	yield of carbonised products.
C.	friability & oxygen content.
D.	calorific value.
Answer» D. calorific value.

Discussion

1054.	Which of the following is not used as a binder in coal briquetting ?
A.	Tar
B.	Molasses
C.	Pitch
D.	Line
Answer» E.

Discussion

1055.	Size of blast furnace grade coke is __________ mm.
A.	25-80
B.	0-15
C.	15-25
D.	>100
Answer» B. 0-15

Discussion

1056.	Presence of __________ in a dry gaseous fuel does not contribute to its calorific value.
A.	sulphur
B.	oxygen
C.	hydrogen
D.	carbon
Answer» C. hydrogen

Discussion

1057.	Junker's calorimeter is used to determine the calorific value of
A.	pulverised coal
B.	gaseous fuels
C.	fuel oil
D.	none of these
Answer» C. fuel oil

Discussion

1058.	The internal energy of the combustion products is __________ compared to that of reactants.
A.	more
B.	less
C.	equal
D.	more or less ; (depends on the state of fuel.)
Answer» C. equal

Discussion

1059.	Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3 /ton of dry coal.
A.	60
B.	160
C.	500
D.	750
Answer» C. 500

Discussion

1060.	For every 10 C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased from 30 to 70 C, the rate of reaction increases __________ times.
A.	8
B.	12
C.	16
D.	32
Answer» D. 32

Discussion

1061.	The single parameter model proposed for describing non-ideal flow is the __________ model.
A.	tank in series
B.	dispersion
C.	both (a) & (b)
D.	neither (a) nor (b).
Answer» D. neither (a) nor (b).

Discussion

1062.	A first order reaction requires two equal sized CSTR. The conversion is
A.	less when they are connected in series.
B.	more when they are connected in series.
C.	more when they are connected in parallel.
D.	same whether they are connected in series or in parallel.
Answer» C. more when they are connected in parallel.

Discussion

1063.	The temperature at which plastic layer formation takes place during carbonisation of coal varies from __________ C.
A.	100 to 150
B.	350 to 450
C.	550 to 650
D.	700 to 850
Answer» C. 550 to 650

Discussion

1064.	Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300 C to avoid the
A.	requirement of large volume combustion chamber.
B.	risk of explosion.
C.	chances of clinker formation.
D.	incomplete combustion of coal.
Answer» C. chances of clinker formation.

Discussion

1065.	The reaction between oxygen and organic material is a/an __________ reaction.
A.	exothermic
B.	endothermic
C.	biochemical
D.	photochemical
Answer» B. endothermic

Discussion

1066.	With decrease in temperature, the equilibrium conversion of a reversible endother-mic reaction
A.	decreases
B.	increases
C.	remains unaffected
D.	increases linearly with temperature
Answer» B. increases

Discussion

1067.	In an exothermic chemical reaction, the reactants compared to the products have
A.	higher temperature
B.	more energy
C.	less energy
D.	same energy.
Answer» C. less energy

Discussion

1068.	In case of physical adsorption, the heat of adsorption is of the order of __________ kcal/kg.mole.
A.	100
B.	1000
C.	10000
D.	100000
Answer» C. 10000

Discussion

1069.	The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is
A.	backmix reactor
B.	plug flow reactor
C.	series of CSTR
D.	PFR in series
Answer» B. plug flow reactor

Discussion

1070.	6 gm of carbon is burnt with an amount of air containing 18 gm oxygen. The product contains 16.5 gms CO2 and 2.8 gms CO besides other constituents. What is the degree of conversion on the basis of disappearance of limiting reactant ?
A.	100%
B.	95%
C.	75%
D.	20%
Answer» C. 75%

Discussion

1071.	Gravity settling process is not involved in the working of a
A.	hydrocyclone
B.	classifier
C.	dorr-thickener
D.	sedimentation tank
Answer» B. classifier

Discussion

1072.	Froth floatation is the most suitable for treating
A.	iron ores
B.	sulphide ores
C.	quartzite
D.	none of these
Answer» C. quartzite

Discussion

1073.	Size reduction of __________ is accomplished in steam heated rollers and roll crushers.
A.	resins
B.	gums
C.	hard rubber
D.	waxes
Answer» D. waxes

Discussion

1074.	The capacity of a belt conveyor depends upon two factors. If one is the cross-section of the load, the other is the __________ of the belt.
A.	speed
B.	thickness
C.	length
D.	none of these
Answer» B. thickness

Discussion

1075.	Which of the following is not a part of the Blake jaw crusher?
A.	Hanger
B.	Check plates
C.	Toggles
D.	Pitman
Answer» B. Check plates

Discussion

1076.	The capacity of a pneumatic conveying system depends upon the
A.	bulk density of materials.
B.	pressure of the conveying air.
C.	diameter of the conveying line.
D.	all (a), (b) and (c).
Answer» E.

Discussion

1077.	If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the
A.	sedimentation
B.	flocculation
C.	dispersion
D.	centrifugation
Answer» E.

Discussion

1078.	Gross and net calorific value of a fuel will be the same
A.	if its ash content is zero.
B.	ifits carbon content is very low.
C.	if its hydrogen/hydrogen compound content is zero.
D.	under no circumstances.
Answer» D. under no circumstances.

Discussion

1079.	Filter aid is used to
A.	increase the rate of filtration.
B.	decrease the pressure drop.
C.	increase the porosity of the cake.
D.	act as a support base for the septum.
Answer» D. act as a support base for the septum.

Discussion

1080.	The distribution given by microscopic analysis of powder is
A.	number
B.	length
C.	area
D.	volume
Answer» B. length

Discussion

1081.	Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of
A.	bronze
B.	stainless steel
C.	flint or porcelain
D.	concrete
Answer» D. concrete

Discussion

1082.	During combustion of gaseous fuels, deficiency of air
A.	lengthens the flame.
B.	tends to shorten the flame.
C.	does not affect the flame length.
D.	increases the flame temperature.
Answer» B. tends to shorten the flame.

Discussion

1083.	Higher efficiency in the combustion of solid fuel can not be achieved by
A.	proper fuel preparation.
B.	keeping the flue gas exhaust temperature very high.
C.	adopting efficient-fuel firing technique & equipment.
D.	supplying correct quantity of combustion air.
Answer» C. adopting efficient-fuel firing technique & equipment.

Discussion

1084.	A coal containing very high percentage of durain is called __________ coal.
A.	bright
B.	splint
C.	non-banded
D.	boghead
Answer» C. non-banded

Discussion

1085.	Low temperature carbonisation
A.	is mainly for producing the smokeless domestic coke.
B.	is meant for the production of 'metallurgical coke'.
C.	produces higher quantity of gas than high temperature carbonisation.
D.	produces less quantity of tar than high temperature carbonisation.
Answer» B. is meant for the production of 'metallurgical coke'.

Discussion

1086.	Which of the following will give maximum gas conversion ?
A.	Fixed bed reactor.
B.	Fluidised bed reactor.
C.	Semi-fluidised bed reactor.
D.	Plug-flow catalytic reactor.
Answer» D. Plug-flow catalytic reactor.

Discussion

1087.	__________ explains the mechanism of catalysis.
A.	Activated complex theory
B.	Collision theory
C.	Thermodynamics
D.	None of these
Answer» B. Collision theory

Discussion

1088.	From among the following, choose one which is not an exothermic process.
A.	Methanol synthesis
B.	Catalytic cracking
C.	Ammonia synthesis
D.	Oxidation of sulphur
Answer» C. Ammonia synthesis

Discussion

1089.	The fractional volume change of the system for the isothermal gas phase reaction, A 3B , between no conversion and complete conversion is
A.	0.5
B.	1
C.	2
D.	3
Answer» D. 3

Discussion

1090.	Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is
A.	added to the feed slurry.
B.	precoated on the filter medium prior to filtration.
C.	separated from the cake by dissolving solids or by burning it off.
D.	all 'a', 'b'&'c'.
Answer» E.

Discussion

1091.	Which of the following is a pressure filter ?
A.	Leaf filter (Moore filter).
B.	Plate and flame filter.
C.	Rotary drum filter.
D.	Sand filter.
Answer» C. Rotary drum filter.

Discussion

1092.	Which of the following relationships between co-efficinet of friction ( ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct ?
A.	> tan
B.	tan
C.	> tan 2
D.	tan
Answer» C. > tan 2

Discussion

1093.	Pick out the wrong statement pertaining to the roll crushers.
A.	Maximum feed size determines the required roll diameter.
B.	For hard material's crushing, the reduction ratio should not exceed 4.
C.	Both the rolls run necessarily at the same speed.
D.	Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced.
Answer» D. Reduction ratio and differential roll speed affect production rate & energy consumed per unit of surface produced.

Discussion

1094.	In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the
A.	square root of the velocity.
B.	square of the viscosity.
C.	filtration time only.
D.	washing time only.
Answer» B. square of the viscosity.

Discussion

1095.	For sizing of fine materials, the most suitable equipment is a
A.	trommel
B.	grizzly
C.	shaking screen
D.	vibrating screen
Answer» E.

Discussion

1096.	Which of the following is not categorised as a "mechanical operation" ?
A.	Agitation
B.	Filtration
C.	Size enlargement
D.	Humidification
Answer» E.

Discussion

1097.	Tabular bowl centrifuges as compared to disk bowl centrifuges
A.	operate at higher speed.
B.	employ bowl of larger diameter.
C.	can not be operated under pressure/vacuum.
D.	can't be used for separation of fine suspended solids from a liquid.
Answer» B. employ bowl of larger diameter.

Discussion

1098.	Which of the following is not an ultrafine grinder (colloid mill)?
A.	Micronizers
B.	Agitated mills and fluid energy mills
C.	Toothed roll crusher
D.	Hammer mills with internal classification
Answer» D. Hammer mills with internal classification

Discussion

1099.	For a non-spherical particle, the sphericity
A.	is defined as the ratio of surface area of a sphere having the same volume as the particle to the actual surface area of the particle.
B.	has the dimension of length.
C.	is always less than 1.
D.	is the ratio of volume of a sphere having the same surface area as the particle to the actual volume of the particle.
Answer» B. has the dimension of length.

Discussion

1100.	In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is
A.	4
B.	1/4
C.	1
D.	1/2
Answer» C. 1

Discussion

Explore topic-wise MCQs in Engineering.

Bituminous coal

Combustion reaction of fuels is a/an __________ reaction.

Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its

Which of the following is not used as a binder in coal briquetting ?

Size of blast furnace grade coke is __________ mm.

Presence of __________ in a dry gaseous fuel does not contribute to its calorific value.

Junker's calorimeter is used to determine the calorific value of

The internal energy of the combustion products is __________ compared to that of reactants.

Yield of coke oven gas in low temperature carbonisation of coal is about __________ Nm3 /ton of dry coal.

For every 10 C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased from 30 to 70 C, the rate of reaction increases __________ times.

The single parameter model proposed for describing non-ideal flow is the __________ model.

A first order reaction requires two equal sized CSTR. The conversion is

The temperature at which plastic layer formation takes place during carbonisation of coal varies from __________ C.

Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300 C to avoid the

The reaction between oxygen and organic material is a/an __________ reaction.

With decrease in temperature, the equilibrium conversion of a reversible endother-mic reaction

In an exothermic chemical reaction, the reactants compared to the products have

In case of physical adsorption, the heat of adsorption is of the order of __________ kcal/kg.mole.

The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is

6 gm of carbon is burnt with an amount of air containing 18 gm oxygen. The product contains 16.5 gms CO2 and 2.8 gms CO besides other constituents. What is the degree of conversion on the basis of disappearance of limiting reactant ?

Gravity settling process is not involved in the working of a

Froth floatation is the most suitable for treating

Size reduction of __________ is accomplished in steam heated rollers and roll crushers.

The capacity of a belt conveyor depends upon two factors. If one is the cross-section of the load, the other is the __________ of the belt.

Which of the following is not a part of the Blake jaw crusher?

The capacity of a pneumatic conveying system depends upon the

If a force greater than that of gravity is used to separate solids &amp; fluids of different densities, the process is termed as the

Gross and net calorific value of a fuel will be the same

Filter aid is used to

The distribution given by microscopic analysis of powder is

Pebble mills are tumbling mills widely used for grinding in the manufacture of paints &amp; pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of

During combustion of gaseous fuels, deficiency of air

Higher efficiency in the combustion of solid fuel can not be achieved by

A coal containing very high percentage of durain is called __________ coal.

Low temperature carbonisation

Which of the following will give maximum gas conversion ?

__________ explains the mechanism of catalysis.

From among the following, choose one which is not an exothermic process.

The fractional volume change of the system for the isothermal gas phase reaction, A 3B , between no conversion and complete conversion is

Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake &amp; reducing the cake resistance during filtration. Filter aid is

Which of the following is a pressure filter ?

Which of the following relationships between co-efficinet of friction ( ) between rock &amp; roll and a (half of the angle of nip) of the particle to be crushed is correct ?

Pick out the wrong statement pertaining to the roll crushers.

In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the

For sizing of fine materials, the most suitable equipment is a

Which of the following is not categorised as a "mechanical operation" ?

Tabular bowl centrifuges as compared to disk bowl centrifuges

Which of the following is not an ultrafine grinder (colloid mill)?

For a non-spherical particle, the sphericity

In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is

If a force greater than that of gravity is used to separate solids & fluids of different densities, the process is termed as the

Pebble mills are tumbling mills widely used for grinding in the manufacture of paints & pigments and cosmetic industries, where iron contamination in the product is highly objectionable. Pebbles used in pebble mill are made of

Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is

Which of the following relationships between co-efficinet of friction ( ) between rock & roll and a (half of the angle of nip) of the particle to be crushed is correct ?