chemical engineering Mcqs
4301. A gas at 0C is cooled at constant pressure until its volume becomes half the original volume. The temperature of the gas at this state will be_______________?
comments icon0
A. -136.5C

B. 0K

C. 136.5K

D. -273C

4302. With increase in the porosity, thermal spalling resistance of fireclay brick_______________?
comments icon0

A. Decreases

B. May increase or decrease

C. Increases

D. Remain same

4303. In case of vapor-liquid equilibria, which of the following does not account for gas phase deviation from ideality ?
comments icon0

A. None of these

B. Use of equation of state

C. Fugacity co-efficient

D. Activity co-efficient
4304. _____________ paint has the minimum absorption co-efficient?
comments icon0

A. Light cream

B. Black

C. White lead

D. Grey

4305. Which of the following is correct ?
comments icon0

A. Resistance = Driving force Rate

B. Rate = Driving force Resistance

C. Driving force = Rate Resistance

D. Rate = Resistance/Driving force

4306. Refractory bricks having lower porosity have _____________________?
comments icon0

A. Low heat capacity

B. Greater strength

C. Low thermal conductivity

D. High insulating properties

4307. Boiling point of a non-homogeneous mixture of immiscible liquids is _____________ that of any one of its separate components?
comments icon0
A. Lower than

B. Either A. or B.; depends on the liquids

C. Equal to

D. Higher than

4308. Fireclay bricks are not used in the________________?
comments icon0

A. Coke oven regenerators

B. By-product coke oven walls

C. Combustion chamber of B.F. stoves

D. Beehive coke oven

4309. Pure oxide refractories are generally monocrystalline in nature and are self bonded ______________ bricks are generally used as moderator in nuclear reactors?
comments icon0

A. Corundum

B. Beryllia

C. Carborundum

D. Thoria

4310. API gravity of water at N.T.P. is about__________________?
comments icon0
A. 10

B. 0

C. 100

D. 1

4311. Methane is mixed with stoichiometric proportion of oxygen and completely combusted. The number of additional specifications required to determine the product flow rate and composition is_______________?
comments icon0

A. 3

B. 2

C. 0

D. 1

4312. jH factor for heat transfer is not a function of the _______________ number?
comments icon0

A. Reynolds

B. Nusselt

C. Grashoff

D. Both B. & C.
4313. For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area___________________?
comments icon0

A. Increases

B. Passes through a maxima

C. Decreases

D. Remain constant

4314. Pick out the wrong statement ?
comments icon0

A. Propagation velocity for travel of heat radiation through vacuum is equal to the velocity of the light

B. The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

C. Heat transfer by radiation cannot occur across an absolute volume

D. In case of a shell and tube heat exchanger, the pressure drop through the shell is proportional to the number of times the fluid crosses the bundle between baffles

4315. Overall thermal resistance for conductive heat transfer through a series of flat resistances is equal to the____________________?
comments icon0

A. Minimum resistance presents in the series

B. Maximum resistance in the series

C. Average of all resistances

D. Sum of all resistances
4316. Duhring?s rule is important in solving problems on__________________?
comments icon0
A. Evaporation

B. Humidification

C. Distillation

D. Crystallisation

4317. The density of a liquid is 1500 kg/m3. Its value in gin/litre will be equal to________________?
comments icon0
A. 1500

B. 15

C. 150

D. 1.5

4318. 1 gm mole of an alcohol whose molecular weight is 74 contains 48 gms of carbon, 10 gms of hydrogen and 16 gms of oxygen. Its molecular formula is__________________?
comments icon0

A. (C2H4)2H2.OH

B. C4H9OH

C. C2H33OH

D. C3H21OH

4319. Pick out the wrong statement ?
comments icon0
A. With change in temperature, the radiant energy emitted by a black body remains unchanged

B. Value of Stefan-Boltzmann constant is 4.876 10-8 KCal/m2.hr.K4

C. Absorptivity of a body approaches unity in case of diffuse reflection

D. Absorptivity of a perfectly black body is unity

4320. Except for monatomic gases, the molal heat capacity at constant volume for all gases is _____________ Kcal/Kg mole. K?
comments icon0

A. < 1

B. > 3

C. < 3

D. 3

4321. If 1.5 moles of oxygen combines with aluminium to form Al2O3, then the weight of aluminium (atomic weight = 27) used in this reaction is __________ gm?
comments icon0
A. 54

B. 27

C. 5.4

D. 2.7

4322. An equation for calculating vapour pressure is given by, log10 P = A B(t + c). This is called the________________?
comments icon0

A. Kopps rule

B. Troutons rule

C. Kistyakowsky equation

D. Antoine equation
4323. Pick out the wrong statement pertaining to a shell and tube heat exchanger ?
comments icon0

A. The maximum value of baffle spacing is equal to the I.D. of the shell

B. The maximum unsupported tube span is generally about 75 times tube diameter, but is reduced to about 60 times for aluminium, copper & alloys of these

C. Disk and doughnut baffle is the most commonly used baffle

D. The minimum value of baffle spacing is 50 mm

4324. A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides __________________?
comments icon0
A. Higher economy

B. Lower capacity

C. Both A. & B.

D. Lower economy

4325. Spalling of silica bricks occurs due to abrupt volume changes, when it is cooled below a temperature of ______________ C?
comments icon0

A. 770

B. 270

C. 70

D. 570

4326. Which of the following ideal gas laws are not applicable to mixture of gases ?
comments icon0

A. Amagats law

B. Daltons law

C. Boyles law & Charles Law

D. None of these

4327. The atomic heat capacities of all solid elements ______________ with decrease in temperature?
comments icon0
A. Decreases

B. Approach zero at 0C

C. Remains unchanged

D. Increases

4328. Pick out the correct equation ?
comments icon0

A. jH = (St)2/3(Pr) = f/2

B. jH = (St)(Pr)2/3 = f/2

C. jH = (St)1/3(Pr) = f/2

D. jH = (St)(Pr)1/3 = f/2

4329. The film thickness for laminar film condensation on vertical surface _____________ from top to bottom?
comments icon0

A. Remain constant

B. Cumulatively decreases

C. Cumulatively increases

D. And the surface conductance increase

4330. Pick out the wrong statement?
comments icon0
A. Heat sensitive materials should be concentrated in high pressure evaporators

B. Steam jet ejector is used for vapor compression in a thermal recompression evaporator

C. The capacity of an evaporator is reduced by the boiling point elevation

D. Corrosive liquid is normally passed through the tubes in a shell and tube heat exchanger

4331. Steam traps are provided in steam carrying pipelines to_________________?
comments icon0

A. Condense steam

B. Release excess steam pressure by bleeding steam

C. Remove condensate and inert gases

D. None of these

4332. Ceramic recuperators used for waste heat recovery from high temperature flue gas going out of the furnace is made of ________________?
comments icon0

A. Siliceous fireclay

B. Silicon carbide

C. Fireclay

D. Corundum

4333. Viscosity of 1 centipoise is equal to 1 Centistoke in case of________________?
comments icon0

A. None of these

B. Carbon tetrachloride

C. Water

D. Mercury

4334. Which is an acidic refractory ?
comments icon0

A. Chrome magnesite

B. Fireclay

C. Magnesite

D. Dolomite

4335. For water evaporating into unsaturated air under adiabatic conditions and at constant pressure, the ____________ remains constant throughout the period of vaporisation ?
comments icon0

A. Dry bulb temperature

B. Humidity

C. Wet bulb temperature

D. Relative saturation

4336. If Prandtl number is greater than the Schmidt number, then the____________________?
comments icon0
A. Thermal boundary layer lies inside the concentration boundary layer

B. Thermal & concentration boundary layers are of equal thickness

C. Hydrodynamic (i.e., momentum) boundary layer is thicker than the other two

D. Concentration boundary layer lies inside the thermal boundary layer

4337. Pick out the wrong statement?
comments icon0

A. In a sieve tray, the minimum hole diameter is equal to the tray thickness

B. In practical operation, distillation towers having diameter 3-6 metres equipped with bubble cap (round) size of 15 cms are used

C. In a stainless steel sieve tray, the minimum hole diameter is equal to 10 times the plate thickness

D. Height of packing in a packed tower is about 3 times the column diameter for raschig rings and about 5 to 10 times the column diameter for saddle packing

4338. A vessel of volume 1000 m3 contains air which is saturated with water vapour. The total pressure and temperature are 100 kPa and 20C respectively. Assuming that the vapour pressure of water at 20C is 2.34 kPa, the amount of water vapour (in kg) in the vessel is approximately ?
comments icon0
A. 17

B. 20

C. 25

D. 34

4339. Presence of MgO in alumino-silicate refractories ______________ its refractoriness ?
comments icon0

A. Either A. or B.; depends on its quantity

B. Increases

C. Does not affect

D. Lowers
4340. Evaporation of 1kg of water from a solution in a single effect evaporator requires about ________________ kg of steam?
comments icon0
A. 1-1.3

B. 1.8-2

C. 0.4 0.6

D. 2 2.4

4341. Dissolving a solute in a solvent does not change its________________?
comments icon0
A. None of these

B. Viscosity

C. Specific heat

D. Vapour pressure

4342. Cox chart which is useful in the design of a distillation column (particularly suitable for petroleum hydrocarbons) is a plot of the_____________?
comments icon0

A. Log (temperature) vs. log (vapor pressure)

B. Vapor pressure vs. log (temperature)

C. Temperature vs. log (vapor pressure)
4343. In panel test for spalling resistance, the average face temperature of panel assembly is maintained at _____________ C for 24 hours?
comments icon0

A. 700

B. 1000

C. 1600

D. 2000

4344. Radiant energy received by a body is proportional to (where, d = the distance between the object emitting radiation and that receiving it.) ?
comments icon0

A. ?d

B. d

C. d1.5

D. d2
4345. Pick out the correct statement?
comments icon0
A. Risers are generally not connected to the plate in a distillation coloumn by bolts, rivets or welding

B. It is preferred to use a vertical condenser for condensation of vapor from a distillation column without sub-cooling

C. Random packing a packed tower offers the advantage of lower pressure drop and higher throughput of fluids as compared to regular/stacked packing

D. Draining of residual liquid on tray during shut down of distillation column is facilitated by weep holes

4346. A compound was found having nitrogen and oxygen in the ratio 28 gm and 80 gm respectively. The formula of the compound is_________________?
comments icon0

A. N2O3

B. None of these

C. N2O4

D. N2O5
4347. Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to__________________?
comments icon0

A. CO attack

B. Thermal spalling

C. Fusion under load

D. Slag attack

4348. The amount of Zn (atomic weight = 65) required to form 224 c.c. of H2 at N.T.P. on treatment with dilute H2SO4will be _____________ gm?
comments icon0

A. 65

B. 6.5

C. 0.65

D. 0.065

4349. Hot metal runner in blast furnace are lined with ______________ bricks?
comments icon0
A. Fireclay

B. Magnesite

C. Silica

D. Carborundum

4350. The number of H+ in 1 c.c solution of pH 13 is__________________?
comments icon0
A. 6.023 107

B. 6.023 1013

C. 1013

D. 6.023 1010