MOCK TEST – 3

1. Match the following

Buoyancy Forces
P. Reynolds number 1.
Viscous forces

Inertial forces
Q. Grashoff number 2.
Viscous forces

Grashoff number
R. Rayleigh number 3.
Re ynolds number

(a) P-1, R-3 (b) Q-1, R-3 (c) P-2, Q-1 (d) Q-2, R-1

Ans: (c)

2. If the critical radius of insulation (critical thickness) for cylinder is 10mm, then what is the
critical radius of insulation for sphere?

(a) 2 cm (b) 5 mm (3) 2 mm (d) 5 cm

Ans: (c)

k
Sol: Cylinder =
h

2k
Sphere =  2  10  20 mm  2cm
h

3. In a gas absorption process, HtG  0.24mand L / mG  1.2, then H toG will be _____(in m).

Ans: 1.5

H TL
Sol: H toG  H TG 
L / mg

0.24
0.3   1.5m
1.2

4. Effective Knudsen diffusivity

S1: is independent of pressure

S2: Varies directly with square root of temperature

 S3: Varies inversely with square root of molecular weight

(a) S1 & S2 are correct (b) S1 & S3 are correct

(c) All are correct (d) None of these

Ans: (c)

5. The exit conversion of reactant of ‘A’ for zero order reaction taking places in a CSTR for the
following data will be _______

Data:

Rate constant = 0.5 mol/min /lt

Feed concentration = 2 mol/ lt

Feed flow rate = 0.25 lt/min

Reactor volume = 2 lt

Ans: 100

T V XA
Sol:  
CAO FA0 rA

V
XA   rA 
FAO

2 1
=  0.5  2
 2.25  2 0.5

6. What is the ratio of reaction rate on particle 1 (Size L1=12mm) to the reaction rate on particle 2
(Size L2= 3cm) if the reaction takes place in the regime of strong diffusion resistance? (Given
that effectiveness factor for particle 1 is 0.12)

(a) 4 (b) 0.48 (c) 2.5 (d) 0.03

Ans: (c)

1
Sol:  
mL

  0.12  strong per diffusion

 1 L 2

2 L1

30 5
=   2.5
12 2

7. In the manufacture of urea, bluret ( NH2CONHCONH2 ) formation is kept minimum because it

(a) Is explosive

(b) Decomposes urea into CO2, N2, & H2O

(c) Contains only 4 wt%, N2

(d) Toxic to animals

Ans: (d)

8. Which type of soaps has excellent property to remove soil and grease?

(a) Cationic type (b) Anionic type (c) Non-ionic type (d) Both (a) & (b)

Ans: (c)

9. A distillation column costs Rs. 50,000. Life time and scrap value are 6 years and 0 respectively.
Assuming effective compound interest of 11% per year, what will be the capitalized cost of the
distillation column?

(a) 11,083 (b) 23,156 (c) 90,195 (d) 107,446

Ans: (d)

 50K 
Sol: Cc  50x  
 1  0.116  1 
 

=107,446

10. Stability analysis of a control system can be done by using frequency response method, which
type of input to be specified?

(a) Step input (b) Ramp input (c) Sinusoidal input (d) no input

Ans: (c)

11. Arrange the following in decreasing order of their emissivities.

 I. Smooth glass II. Plaster III. aluminum IV. Concrete

(a) I, II, III, IV (b) I, II, IV,III (c) I, III,IV,II (d) I, III,II,IV

Ans: (b)

12. Which of the following statements is correct for a Schmidt number of value 2?

(a) Mass diffusivity is two times the momentum diffusivity

(b) Thermal diffusivity is two times the momentum diffusivity

(c) Momentum diffusivity is two times the mass diffusivity

(d) Momentum diffusivity is two times the thermal diffusivity

Ans: (c)

13. If LMTD correction factor for a heat exchanger is 0.81, then I is ____ to design that equipment

(a) Desirable (b) Not desirable (c) Cant say (d) None of these

Ans: (b)

Sol: For F7 (LMTD correction factor) value above 0.80, hence is not desirable to design the heat
exchanger

14. What are the dryness fraction values for a liquid just starts boiling and for the vapour which is
formed after complete vaporization?

(a) 0,1 (b) 1,0 (c) Between 0 and 1 (d) Greater than 1

Ans: (a)

mv
Sol: Dryness fraxtion x 
mv  ml

Fir liquid just starts boiling m=0, x=0

For vapour formed after complete vaporization

mv
m2  1
ml  mv

15. The percentage of Na 2SO4 present in one mole of Na 2SO4 .5H2O will be _____ than t5he

percentage of Na 2SO4 present in Na 2SO4 10H2O

 (a) Greater (b) Less (c) Equal (d) None

Ans: (a)

142
Na 2SO4 .5H 2o  100  62
232

142
Na 2SO4 in Na 2SO4 .10H 2O  100
312

= 44

16. Which of the following statements is correct, if the slope of operating line is ‘m’ times the slope
of equilibrium line?

(a) HTU>HETP (b) HETP>HTU (c) HETP=HTU (d) Depends on ‘m’

Ans: (c)

Sol: if operating line is parallel to equal line, than HETP is greater than HTU

17. Hydrolysis of oil and fats with _____ gives a mixture of glycerol and fatty acid, whereas the
hydrolysis of oil and fats with _____ gives a mixture of glycerol and soap.

(a) Acid, Alkali (b) Alkali, Acid (c) Acid, water (d) none of these

Ans: (a)

Sol: Glycerol+3NaoH  Glycerol+3R-COONa

With the acid and water they will give glycerol and fatty acid

18. What is the order of a reaction for ammonia fabrication from the nitrogen and hydrogen ?

(a) 2 (b) 1 (c) 0 (d) cannot say

Ans: (d)

Sol: Unless it is mentioned Reaction is elementary or not

We cant say

19. The half life period of a first order irreversible reaction is a

(a) Constant (b) Function of initial concentration

(c) Function of temperature (d) none of these

 Ans: (c)

rR k
20. For the parallel reaction given below, the quantity is given by 1 , then which of the
rS k2
following is correct for the product distribution of the above reaction?

R
K1

A
K2 S

K1
(a) The product distribution is fixed by
K2

(b) The product distribution is unaffected by using the type of ractor.

(c) Both A & B

(d) None of these

Ans: (c)

21. Find the area |in mm2| of openings in one screen (Taylor series) such that area of openings in the
next smaller opening is 10mm2 ________

Ans: 20

A2
Sol:  2 A 2  2 10 mm2  20
A1

22. A large body A of emissive power 180 W/m2 and absorptivity 0.6 enclosed a small body B of
emissive power 190 W/m2 and are in thermal equilibrium with their environment. Find the
absorptivity of smaller body ‘B’ __________

Ans: 0.63

EA EB E B A
Sol:  B 
A B EA

190  0.6
B   0.63
180

23. Which of the following material will have the same temperature profile shown in the figure
during heat transfer?
 (a) Insulating body (b) Low conductivity fluid

(c) High conductivity fluid (d) none of these

Ans: (b)

Sol: Low conductivity fluid have the same temperature

24. A steam pipe of thermal conductivity 0.65 W/m.K and diameter 120 mm is placed horizontally
in air 320C such that heat is lost from steam pipe. Calculate the heat transfer coefficient if the
Nusselt number is 30 and thermal conductivity of air is 0.04 W/m.k

(a) 7 W/m2.K (b) 16 W/m2.K (c) 10 W/m2.K (d) 22W/m2 K

Ans: (c)

hD
Sol: Nu=
K

h 120 103 
30 
0.04

h= 10W/m2.K

25. Find the value of Lewis number for a mass transfer process for which Reynold’s number is
16000, Schmidt number =840 and Prandtl number = 400.8________

Ans: 2.094

Sc 840
Sol: Le    2.094
Pr 400.8

26. In a falling rate period, the rate of drying is directly proportional to (t) n. find the value of ‘n’ if ‘t’
is the thickness of material

(a) 1 (b) -2 (c) -1 (d) 2

 Ans: (b)

1
Sol: Rate of drying 
 thickness 
2

27. Which of the following statement is correct about Knudsen diffusion?

(a) Mean free path of the gas molecules is greater than the pore diameter

(b) Gaseous collisions are more frequent that collision of molecules with pore walls

(c) Catalytic reaction requires more activation than homogeneous reaction

(d) For irreversible reaction rate always decreases with temperature

Ans: (a)

Sol: For Knudsen diffusion mean path > pore diameter

28. The half life of a reaction is given:

t1/2   23/2  1 .2CAC3/2

What is the order of the reaction ?

5 3 1
(a) (b) (c) 3 (d)
2 2 2

Ans: (a)

Sol: t1/2CAO1n

3
1 n 
2

Order of reaction n=5/2

29. A gaseous phase reaction 3P  Q where 60 mole% P and 40 mole % inerts , find the expansion
factor

(a) -0.2 (b) 0.4 (c) 0.2 (d) -0.4

Ans: (d)

Sol: 3P  Q
 VA1  VA0 0.2  0.6
A    0.4
V A0 1

30. Which of the following statement is correct about membrane to produce caustic soda?

(a) Chlorine contaminated caustic soda is produced

(b) Electric energy consumption is more than the mercury process

(c) Very high purity brine required

(d) Low cost and long life time of the membrane

Ans: (c)

31. A horizontal rectangular channel has a discharge of 8.0 m3s/m width of the channel. In a
hydraulic jump occurring in this channel, the depth before and after the jump is 0.5 m and 4.75 m
respectively. Calculate the energy loss in the jump

(a) 8.365m (b) 8.653m (c) 8.563m (d) 8.065m

Ans: (b)

q 8
Sol: V1    16m / s
g1 0.5

8
V2   1.684m / s
4.15

V12 V2
 Z  1  ZL
2g 2g
L  8.653m

32. Triple glazed windows shown below are used in much closed climates. Calculate the R-value for
the window, if the thermal conductivity of air at normal room temperature is approximately
0.015 Btu/h.ft0F and the thermal conductivity of window glass is 0.78W/mK.

(a) 2.8 (b) 8.2 (c) 3.6 (d) 4.2

 Ans: (a)

Sol: K glass = 0.78  0.37782  645 Btu/h.ft0F

0.08
R glass   0.0148
12  0.45

0.25 /12
Rair=  1.3889
0.015

R value = 3 R glass+2 Rair

=2.8

33. A duct carries hot waste gas from a process unit to a pollution control device. The duct cross
section is 4ft  4ft and it has a surface temperature of 1400C. ambient air at 200C blows across
the duct with a wind speed of 10 m/s. the rate of heat loss per meter (in W/m) of duct length will
be __________.

(assume data: Kinematic viscosity is 2.15 106 ; Nu  0.1202Re0.654 )

Conductivity K= 0.0293, (in SI units)

Ans: 9800

140  20
Sol: Tf =  800 C
2

1.22 10
Ri=  5.674 105
2.15 106

Nu=0.1202 Ri0.654=6965

H=16.7 W/m

A= 4 1.22 10  4.88m 2

q= HAT  167  4.88  144.20  9800W / m

34. The atmospheric air is a mixture of nitrogen and oxygen in the mole ratio 79:21. It is required to
separate 1 mol /sec of air at 1 bar 300K into its pure components at 1 bar and 300K. the
minimum power (kW) required to separate the air will be _____________

(Surroundings are at 300K and treat air as an ideal gas)

 Ans: 1.282

Sol: Entropy change due to mixing

s  R  x i ln x i   si  se 

Wmin= RTo  x i ln x i

= 8.314  300  0.79ln 0.79  0.21ln 0.21 

= 1281.9 J/s

Min power required = 1.28W

35. A crystallizer is changed with 7500kg of aqueous solution at 104 0C containing 29.6% by weight
of anhydrous Na 2SO4 . the solution is then cooled to 200C. during this operation, 5% of water is
lost by evaporation and Glauber’s salt crystallizes. Solubility at 200C = 194g Na2SO4/100h water

Molecular weight of Glauber’s salt (Na2SO4.10H2O)=142+180=322

The yield of crystals in kgs will be ________

Ans: 3749.5

Sol: Na 2SO4 %  7500  0.296  2220kg

H2O percent= 7500-2250=5280 kg

H2O lost = 5280  0.05  264kg

H2O remaining = 5280-264=5016 kg

Let

X= kg of Glauber salt crystallizer

 X   Y 
Y= wt of the solution Na2SO4 balance = 2220  142    19.4  
 322   1194 

 X   Y 
H2O balance = 5016= 180    100  
 322   199.4 

Solving X=3749.5 kg

Y=3486.5 kg
36. What is the rate constant value for second order reaction, if the initial concentration is
mol
5 104 and is decreased by 40% in 50 min?
lit

[Consider as decomposition of a gas]

(a) 13.33 (b) 26.67 (c) 38.93 (d) 46.64

Ans: (b)

Sol: IInd order

 1 1 
    Kt
 CA CAO 

t=30 min

2 104
K  26.66 mol1 min 1
3  250

37. Match the following amines given in List- I with their usage in List – II

List – I List – II
P. Monomethyl amine 1. Used in the manufacturing of
dimethyl formamide and
acetaamide
Q. Dimethyl amine 2. Used to form cholin chloride,
biocies and slimicides
R. Trimethylamine 3. Used in explosive, insecticides
and surfactants
(a) P-3, Q-2, R-1 (b) P-2, Q-3, R-1 (c) P-1, Q-2, R-3 (d) P-3, Q-1, R-2

Ans: (d)

38. Match the following humidity measuring apparatus in List-I with their functioning in List – II

List – I List – II
P . Direct chemical Method 1. Measurement done using the
electrical conductivity
Q. Hygrometer method 2. Measurement done using the
dry bulb and wet bulb
temperatures
 R. Sling psychrometer method 3. Measurement based on
expansion and contraction of
materials like hair, wood, animal
membrane and paper
S. Dew point method 4. Measurement done using
chemical like H2SO4, P2O5 etc
(a) P-2, Q-1, R-4,S-3 (b) P-3, Q-2, R-1, S-4

(c) P-4, Q-3, R-2, S-1 (d) P-1, Q-3, R-2, S-4

Ans: (c)

39. A power plant taps steam superheated by geothermal energy at 505K (the temperature of the hot
resorvoir) and uses the steam to do work in turning the turbine of an electric generator. The
steam is then converted back into water in a condenser at 323K (the temperature of the cold
reservoir), after which the water pumped back into the ground where it is heated again. The
output of the generator is 84MW. Calculate the minimum amount of rejected heat (in MJ) that
must be removed from the condenser every 24 hours?

(a) 1.288 107 (b) 2.818 107 (c) 8.128 107 (d) 1.822 107

Ans: (a)

W
Sol: Efficiency =
QA

Tc
= 1  0.36
Tn

W=Qn-Qc

W
 2.33MW
effc

Qc  233  84

= 149 MW

149  24  3600  1.28 107 MJ

40. Match the following polymerization techniques in List –I that is mostly used for the preparation
of the polymers given in List- II
 List – I List –II
P. Bulk polymerization 1. Used for preparation of polyvinyl
acetate
Q. Solution Polymarization 2. Used for commercial preparation
of polyvinyl chloride and polystyrene
R. Suspension polymerization 3. For preparation of high density
polyethylene and polypropylene
S. Emulsion polymerization 4. Methyl methacrykate to Plexiglas
(a) P-4, Q-3, R-1, S-2 (b) P-4, Q-3, R-2, S-1

(c) P-3, Q-4, R-1, S-2 (d) P-3, Q-4, R-2, S-1

Ans: (b)

41. Match the following model (List- I) which has proper residence time distribution (List -II)

List -I List – II
P. CSTR followed by PFR

1.
Q. PFR followed by CSTR

2.
R. CSTR with bypass

3.
S. PFR with bypass

4.
(a) P-1, Q-2, R-3 (b) Q-1, R-2, S-3 (c) R-2, S-3,P-4 (d) S-3, P-4, Q-1

Ans: (b)

42. (Brary lethenol(1) Methyl acetate (2)) mixture is given at pressure 200kPa and 80 0C

Data:
 A B C
B
In P / kPa  A 
sat
Methanol 16.5938 35644.3  33.39
TC
Methyl Acetate 14.4015 2739.17  50.03

What will be the X2 mole reaction of methyl acetate? _________

Ans: 0.615

3644.3
Sol: in Psat  16.59 
353  33.59

 5.19

2739.17
In P2sat  14.4015 
353  50.03

 5.36

P1sat  180 kPa

P2sat  212.5kPa

P  X1P1sat  X2 P2sat

200  1  X2 180  X2  212.5

X2 = 0.615

43. In an oil refinery plant a heat exchanger of area 100cm2 was purchased in 1993 at a cost of Rs.
3,00,000. In 1999, another heat exchanger of area 20m2 was added. Marshall land swift index
was 1048.5 in 1993 and 1116.9 in 1999. If the cost scales as capacity 0.54, then evaluate the cost
of the 2nd evaporator __________.

Ans: 1,34,010

Sol: 1993 100cm3

C1  3,00,000

0.54
C2  20 
 
C1  100 

C2  0.4193  3,00,000
 = 1,25,800

C1999  1,34,010

44. An evaporator cost of $10,000 has 8 years of life time. Find the book value of the unit at the end
of 4 years. (Use double declining method for depreciation)

(a) $7314 (b) $ 5126 (c) $ 3164 (d) $ 2347

Ans: (c)

2 2
Sol: f    0.25
N 8

P4  P0 1  f 
n

= 104(0.75)4

= 3164

45. An object spherical shape of 3cm diameter at 1000C is suspended in air. The sphere is enclosed
by 10cm dome at 2500C, with absorptivity and emissivity of 1. The dome and sphere are
concentric. What is the radiative heat loss from sphere and dome? Given emissivity of the sphere
is 0.9.

(a) 2.8W, 133.27 W (b) 2.8W, 66.63W (c) 5.6W, 133.27W (d) 5.6W, 66.63 W

Ans: (b)

Sol: qsphere = 0.9  5.67 10 2  4 0.01512   373 4

= 2.7 W

qdone= 1 5.67 108  2  0.05  5234

2

= 66.63 W

46. Match the following monomer (List - I) with corresponding polymer (List - II)
 List –I List –II
P- Chloroethene 1. Nylon
Q. Amide 2. Poly vinyl chloride
R. Ethene 3. Poly ethane
S. Ethylene
(a) P-2, Q-1, R-3 (b) P-3, S-2, R-1

(c) Q-3, R-1, S-2 (d) R-1, S-2, P-3

Ans: (a)

47. Which of the following reactions are endothermic?

(i) 2NH3  CO2 NH2CONH2  H2O

(ii) N2  2H2 2NH3 Haber process

(a) Neither (i) nor (ii) (b) Both (i) and (ii)

(c) Only i (d) Only ii

Ans: (a)

48. Let the inflation rate be 6% per year. If a person deposits Rs. 50,000 in a bank at 9% per annum
simple interest for 10 years, will this effectively protect the purchasing power of the original
principal?

(a) Purchasing power of the investment will not be protected

(b) Purchasing power of the investment will be protected

(c) Investment will be protected without any increment

(d) None of these

Ans: (d)

Sol: P  50000 1  0.09

10

= 118368
 118368
P  66096
1  0.06
10

66096 > 50,000

49. If a bowl of liquid is heated at 1000C and it takes 40 minutes to evaporate, but if it is heated to
1500C, it needs only 20 minutes to evaporate. The activation energy for this process is ________

(Take in2= 0.69)

Ans: 18185

r2 t E1 1 
Sol: ln  ln 1    
r1 t 2 R  T1 T2 

40 E  1 1 
ln  
20 8.314  373 423 


E= 18185.05J/Kmol

50. A binary mixture of 10 Kg mol benzene and toluene containing 40-mol percent, benzene is to
distilled at atm pressure to recover 95% of the benzene. If the residue is 6 kg mol, then the
residue composition for toluene is __________

Ans: 0.967

Sol: 10=D+W

D=4

F *yf = D* yd  W* x w W  w  4  3.8  0.2

6  0.2
YW =  0.967
6