Explore topic-wise MCQs in Chemical Engineering.

This section includes 408 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.

101.

The advantage of firing pulverised coal in the furnace lies in the fact, that it____________________?

A. Permits the use of high ash content coal
B. Permits the use of low fusion point ash coal
C. Accelerates the burning rate and economises on fuel combustion
D. All A., B. and C.
Answer» D. All A., B. and C.
102.

Safe condition for storage of high V.M. bituminous coal is that ___________________?

A. Height of the coal heap should be < 3 metres
B. Maximum 200 tons should be stored in a heap
C. Both A. and B.
D. Neither A. nor B.
Answer» D. Neither A. nor B.
103.

Removal of hydrogen from coke oven gas ___________________?

A. Increases its calorific value
B. Decreases its calorific value
C. Does not alter its calorific value
D. Is not possible on commercial scale
Answer» B. Decreases its calorific value
104.

Ratio of primary air to secondary air increases with increase in the rank of coal, because the__________________?

A. High rank coals have higher amount of volatile matter
B. Ratio of fixed carbon to volatile matter increases
C. Oxygen content progressively decreases
D. Calorific value of the coal increases
Answer» C. Oxygen content progressively decreases
105.

Rate of low temperature oxidation of coal due to bad storage conditions_______________?

A. Decreases with increase in surface area
B. Does not vary with increase in surface area
C. Is more for low volatile coal compared to high volatile coal
D. Is accelerated by storage in large heaps with small surface to volume ratio
Answer» E.
106.

Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around ______________ Nm3?

A. 30
B. 300
C. 3,000
D. 30,000
Answer» C. 3,000
107.

Quantity of coke produced from metallurgical coal may be around _____________ percent?

A. 30
B. 50
C. 75
D. 95
Answer» D. 95
108.

Purity of coke means that, it is high in carbon and low in __________________?

A. Volatiles
B. Ash
C. Iron
D. Moisture
Answer» B. Ash
109.

Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is __________________?

A. 20
B. 12.5
C. 0
D. 10
Answer» D. 10
110.

Pulverised coal used in boiler firing need not have____________________?

A. Less moisture content
B. High fusion point of its ash
C. High bulk density
D. Lower ash content
Answer» C. High bulk density
111.

Proximate analysis of coal determines its ______________ content?

A. Moisture, ash, sulphur & volatile matter
B. Moisture, volatile matter, ash & fixed carbon
C. Moisture, sulphur, nitrogen & fixed carbon
D. None of these
Answer» C. Moisture, sulphur, nitrogen & fixed carbon
112.

_____________ prohibits the use of alcohols directly in petrol engines ?

A. Low octane number
B. High cost & availability
C. Low flash point
D. Low calorific value
Answer» C. Low flash point
113.

Producer gas comprises mainly of _______________________?

A. CO & N2
B. CO & H2
C. CO2 & N2
D. CO2 & H2
Answer» B. CO & H2
114.

Producer gas containing least amount of tar is produced by the_________________?

A. Partial combustion of coal
B. Partial combustion of large size (< 50 mm) coke
C. High pressure gasification of coal (e.g. in Lurgi gasifier)
D. Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)
Answer» C. High pressure gasification of coal (e.g. in Lurgi gasifier)
115.

____________ process is meant for direct hydrogenation of coal to produce liquid fuel?

A. Fischer-Tropsch
B. Bergius
C. Lurgi
D. None of these
Answer» C. Lurgi
116.

Prime coking coal is always blended with medium or non- coking coal before carbonisation__________________?

A. To check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls
B. Because, it alone produces unreactive coke
C. Both A. and B.
D. Neither A. nor B.
Answer» D. Neither A. nor B.
117.

_____________ present in coal is not determined in its ultimate analysis ?

A. Fixed carbon
B. Total carbon
C. Hydrogen
D. Nitrogen
Answer» B. Total carbon
118.

Presence of phosphorous in metallurgical coal__________________?

A. Is not undesirable
B. Reduces its calorific value
C. Badly affects the quality of steel
D. Increases its caking power
Answer» D. Increases its caking power
119.

Presence of nitrogen in combustion air does not reduce the ____________________?

A. Amount of heat liberated
B. Flame temperature
C. Flue gas temperature
D. Any of the above
Answer» B. Flame temperature
120.

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
121.

Presence of free moisture in coal is most disadvantageous during_________________?

A. Its pulverisation (as it requires more power)
B. Combustion of fire slacks on the grates
C. Handling (e.g. when emptying wagons)
D. None of these
Answer» B. Combustion of fire slacks on the grates
122.

Presence of force moisture in coal is most disadvantageous during its __________________?

A. Transportation and handling
B. Washing
C. Pulverisation
D. Storage
Answer» D. Storage
123.

Presence of free moisture in coal during its high temperature carbonisation _____________________?

A. Reduces the coking time
B. Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls
C. Increases the loss of fine coal dust from the ovens when charging
D. None of these
Answer» C. Increases the loss of fine coal dust from the ovens when charging
124.

Preheating of ______________ the flame temperature?

A. The gaseous fuel before combustion decreases
B. Combustion air decreases
C. Either the fuel or the air or both, increases
D. Either the fuel or the air does not affect
Answer» D. Either the fuel or the air does not affect
125.

Preheating of combustion air is done to ___________________?

A. Increase the adiabatic flame temperature
B. Increase the calorific value of the fuel
C. Complete the combustion of fuel
D. Reduce its requirement for effecting the complete combustion
Answer» B. Increase the calorific value of the fuel
126.

Preheating of a gaseous fuel results in increased____________________?

A. Flame length
B. Flame temperature
C. Quantity of flue gas
D. Ignition temperature
Answer» C. Quantity of flue gas
127.

Preheating of coal charge for the coke ovens reduces the __________________?

A. Time of carbonisation
B. Yield of gas and tar
C. Fuel consumption in coking
D. All A., B. and C.
Answer» E.
128.

Power alcohol as compared to straight run gasoline has lower ________________?

A. Calorific value
B. Octane number
C. Specific gravity
D. Viscosity
Answer» B. Octane number
129.

Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its ___________________?

A. Emissivity factor is higher
B. Sulphur content is lower
C. Flue gas has lower dew point thereby facilitating more waste heat recovery
D. All A., B. and C.
Answer» E.
130.

Pick the odd man out?

A. Briquettes
B. Wood
C. Oil gas
D. Pitch creosote mixture
Answer» C. Oil gas
131.

Percentage of nitrogen in blast furnace gas may be around__________________?

A. 5
B. 25
C. 55
D. 80
Answer» D. 80
132.

Percentage of hydrogen in coke oven gas may be around ___________________?

A. 10
B. 25
C. 45
D. 60
Answer» E.
133.

Percentage of methane in coke oven gas may be around _____________________?

A. 5
B. 15
C. 25
D. 50
Answer» D. 50
134.

Percentage of carbon monoxide in blast furnace gas may be around ____________________ ?

A. 8
B. 14
C. 22
D. 52
Answer» D. 52
135.

Pensky-Marten apparatus is used for those oils, whose flash points are _____________ °F?

A. < 120
B. > 120
C. < 90
D. 90-110
Answer» C. < 90
136.

Oxygen percentage (by weight) in atmospheric air is_________________?

A. 19
B. 21
C. 23
D. 29
Answer» D. 29
137.

Oxygen required for theoretically complete combustion of 1 Nm3 methane is ______________ Nm3?

A. 2
B. 4
C. 6
D. 1
Answer» B. 4
138.

Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around ______________ percent?

A. 4
B. 96
C. 20
D. 40
Answer» D. 40
139.

“Overfire burning” in a furnace is a phenomenon characterised by the __________________?

A. Supply of excess fuel
B. Supply of excess air
C. Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air
D. None of these
Answer» D. None of these
140.

Out of the following fuels, the difference between the net and gross calorific value is maximum in case of_________________?

A. Pitch
B. Fuel oil
C. Blast furnace gas
D. Bituminous coal
Answer» C. Blast furnace gas
141.

Out of the following fuels, the difference between gross and net calorific value will be minimum in case of___________________?

A. Coke oven gas
B. Water gas
C. Natural gas
D. Blast furnace gas
Answer» E.
142.

Orsat apparatus__________________?

A. Gives flue gas analysis on dry basis
B. Determines N2 in flue gas indirectly
C. Can’t determine CO in flue gas, if it is < 0.2%
D. All A., B. & C.
Answer» E.
143.

Orsat apparatus is meant for ___________________?

A. Gravimetric analysis of flue gas
B. Finding out combustion efficiency
C. Direct determination of nitrogen in flue gas by absorbing it in ammoniacal cuprous chloride
D. None of these
Answer» E.
144.

Optimum preheating temperature for pitch creosote mixture (PCM) which is also termed as C.T.F-200, before atomisation through burners is_________________?

A. 200 °F
B. 200 °C
C. 200 °K
D. 200 °R
Answer» B. 200 °C
145.

One kg of carbon for theoretically complete combustion requires ______________ kg of air?

A. 11.5
B. 0.5
C. 23
D. 12
Answer» B. 0.5
146.

ombustion of pulverised coal compared to the lumpy coal __________________?

A. Provides better control of furnace temperature
B. Facilitates combustion with lower excess air
C. Provides higher thermal efficiency & flame temperature
D. All A., B. & C.
Answer» E.
147.

Of the total tar present in raw coke oven gas, the tar recovered in primary cooler is about _______________ percent?

A. 5
B. 25
C. 55
D. 75
Answer» C. 55
148.

_____________ of the coal is the basis for Seylor’s coal classification?

A. Proximate analysis
B. Ultimate analysis
C. Caking index
D. Calorific value
Answer» C. Caking index
149.

Octane number of 2, 2, 4 – trimethyl pentane is __________________?

A. 0
B. 100
C. In between 0 and 100
D. More than 100
Answer» C. In between 0 and 100
150.

Number of macrocomponents present in coal according to Stopes are ___________________?

A. Four
B. Five
C. Six
D. Two
Answer» B. Five