Question with Answer Gate - Chemical Engineering

Q1. Select the wrong statement regarding water gas shift converters from the list below.

1. inter –stage cooling is provided between the two stage of shift converters.
2. Usually high temperature shift(HTS)reactor has a iron-based catalyst and low temperature shift(LTS) reactor has a copper-based catalyst.
3. HTS reactor is followed by LTS reactor.
4. LTS reactor is followed by HTS reactor.

Answer: D

Q2. A catalyst slab of half-thickness L (the width and length of the slab>>L) is used to conduct the first order reaction A→B. At 450K ,the Thiele modulus for this system is 0.5. The activation energy for the first order rate constant is 100kJ/mol. The effective diffusivities of the reactant in the slab can be assumed to be independent of temperature , and external mass transfer resistance can be neglected. If the temperature of the reaction is increased to 470K, then the effectiveness factor at 470K (up to two decimal place)will be_________.

1. 0.6
2. 0.7-0.9
3. 1.67
4. 2.0-2.3

Answer: B

Q3. A binary feed consisting of 25mol% liquid and 75mol% vapour is separated in a staged distillation column. The mol fraction of the more volatile component in the distillate product is 0.95. The molar flow rate of distillate is 50% of the feed flow rate and McCabe-Thiele method can be used to analyze the column. the q-line intersects the operating line of the enriching section at (0.35,0.5)on the x-y diagram. The slope of the stripping section operating line (up to one decimal place)is_____.

1. -1
2. 0.8
3. 1.4
4. 2

Answer: C

Q4. A proposed chemical plant is estimated to have a fixed capital (FC) of 24Rs crores. Assuming other costs to be small ,the total investment may be taken to be same as FC. After commissioning (at t=0 years), the annual profit before tax is 10 Rs crores/year (at the end of each year) and the expected life of the plant is 10 years. The tax rate is 40% per year and a linear depreciation is allowed at 10% per year. The salvage value is zero. If the annual interest rate is 12% the NPV (net present value of worth) of the project in crores of rupees(up to one decimal place)is_________.

1. -1.78
2. 0
3. 15-15.5
4. 22-24.7

Answer: C

Q5. Adsorption on activated carbon is to be used for reducing phenol concentration in wastewater from 0.04mol/1 to 0.008mol/1. The adsorption isotherm at the operating temperature can be expressed as q= 0.025C 1/3 ; where q is the phenol concentration in solid (mol/g solid)and c is the phenol concentration in water(mol/1). the minimum amount of solid(in grams)required per liter of wastewater (up to one decimal place)is

1. 50.0
2. 5.4-5.7
3. 58.7
4. 6.3-6.5

Answer: D

Q6. The solution of the non-linear equation x 3 -x=0 is to be obtained using Newton- raphson method. If the initial guess is x =0.5,the method converges to which one of the following values:

1. -1
2. 0
3. 1
4. 2

Answer: A

Q7. A centrifugal pump delivers water at the rate of 0.22m 3 /s from a reservoir at a height H, through a vertical pipe of 0.2m diameter. Both the reservoirs are open to atmosphere. The power input to the pump is 90kw and it operates with an efficiency of 75%. Data: Fanning friction factor for pipe flow is f=0.004.Neglect other head losses. Takes gravitational acceleration, g=9.8m/s 2 and density of water is 1000kg/m 3 . The height H,in meters, to which the water can be delivered (up to one decimal place)is ________.

1. 25-27
2. 30-35
3. 20-23
4. 10-15

Answer: A

Q8. An ideal gas is initially at a pressure of 0.1 MPa and a total volume of 2m 3 .It is first compressed to 1MPa by a reversible adiabatic process and then cooled at constant pressure to a final volume of 0.2m 3 . the total work done(in kJ)on the gas for the entire process (up to one decimal place)is______. Data: R = 8.314J/molK; heat capacity at constant pressure (C P )=2.5R

1. 610
2. 750
3. 460
4. 570

Answer: B

Q9. Identify the WRONG statement amongst the following:

1. steam distillation is used for mixtures that re immiscible with water.
2. Vacuum distillation is used for mixtures that are miscible with water.
3. Steam distillation is used for mixtures that are miscible with water.
4. vacuum distillation columns have larger diameter as compared to atmospheric columns for the same throughout.

Answer: C

Q10. A cylindrical packed bed of height 1m is filled with equal sized spherical particles. The particles are nonporous and have a density of 1500kg/m 3 .The void fraction of the bed is 0.45. The bed is fluidized using air (density 1kg/m 3 ). If the acceleration due to gravity is 9.8m/s 2 , the pressure drop (in pa) across the bed at incipient fluidization(up to one decimal place) is ____.

1. 4400
2. 5054-5080
3. 6407
4. 8080-8100

Answer: D