GATE 2026 Question Paper Chemical Engineering (CH)

FOR GATE EXAM PREPARATION

GATE 2026
Question Paper ·
Chemical Engineering
(CH)
EXAM YEAR TYPE SUBJECT

GATE 2026 Question Paper Chemical Engineering (CH)

Notes · Sample Papers · Previous Year Papers · Mock Tests

m
m .co

m .co s e m

se g l a
a
General Aptitude (GA)
Q.1 – Q.5 Carry ONE mark Each

Q.1 “He often _____ the numbers. False claims are not going to help. Honesty _____
trust”, said the manager.
m
m .co
Choose the option with the correct order of words to fill the blanks.

.co s e m
s em l a
g la ag
(A) a exaggerates; engenders

(B) excels; encourages

(C) aggravates; alleviates

m
.co
(D) diminishes; eliminates

e m
las
ag

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 1 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 1 of 40

Q.2 In the sequence of tiles shown below, the missing tile indicated by the question
mark should be

(A)

(B)

(C)

(D)

Organizing Institute: IIT Guwahati Page 2 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 2 of 40

m
m .co

m .co s e m

se g l a
a

Q.3 A school has 100 students distributed among 1st to 10th standards.

Based on this, which one of the following statements is always correct?

m
m .co
.co s e m
(A)
s em
There are at least 10 students who belong to the same standard.
l a
g la ag
(B) a There is at least one student in each standard.

(C) There are at most 10 students in 10th standard.

(D) The total number of students from 1st to 5th standards is at least 50.

m
m .co
s e
la
Q.4 How many 3-digit numbers can be formed using three distinct single digit prime
numbers?
ag

(A) 64

(B) 24
m
m
c. o(C) m.co
m
12
s e
s e g l a
g la (D) 4 a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 3 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 3 of 40

Q.5 In a group of students, 10 students like Mathematics, 12 students like English,
4 students like both Mathematics and English, and 6 students like neither
Mathematics nor English. The number of students in the group is ____

(A) 18

(B) 20

(C) 24

(D) 32

Organizing Institute: IIT Guwahati Page 4 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 4 of 40

m
m .co

m .co s e m

se g l a
a
Q.6 – Q.10 Carry TWO marks Each

Q.6 Charity : P :: Retaliation : Q

Choose the appropriate pair of words P and Q that fit the analogy.

m
m .co
.co s e m
(A)
s em
P = Parsimonious; Q = Vengeful
l a
g la ag
(B) a P = Altruistic; Q = Amicable

(C) P = Resentful; Q = Spiteful

(D) P = Magnanimous; Q = Vindictive

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 5 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 5 of 40

Q.7 A paper shown in Panel I is folded along the dashed lines (- - -) to construct a
cube. The shaded regions shown in Panel I appear on the outer surface of the cube.
Referring to cubes shown in Panel II, which one of the options is correct?

(A) Only (i) can correspond to the unfolded cube in Panel I.

(B) Only (ii) can correspond to the unfolded cube in Panel I.

(C) Both (i) and (ii) can correspond to the unfolded cube in Panel I.

(D) Neither (i) nor (ii) can correspond to the unfolded cube in Panel I.

Organizing Institute: IIT Guwahati Page 6 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 6 of 40

m
m .co

m .co s e m

se g l a
a
Q.8 Consider the cube shown below with its 8 corners labelled a, b, c, d, e, f, g,
and h. The figure is representative. All corners are to be colored such that any two
corners that are connected by an edge must be of different colors. The minimum
number of colors required to achieve this is ________

m
m .co
m .co s e m
s e l a
g l a ag
a

m
m .co
s e
(A) 8
g la
a
(B) 4

(C) 3

(D) 2
m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 7 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 7 of 40

Q.9 Four hills H1, H2, H3, and H4 are present in an area. The following observations
are made about them:

i. Neither H2 nor H3 is the easternmost hill.
ii. Neither H2 nor H3 is the westernmost hill.
iii. Neither the easternmost hill nor the westernmost hill is the southernmost
hill.
iv. Two hills are located to the west of H2.
v. The southernmost hill has at least two hills to its east.

The southernmost hill is ________.

(A) H1

(B) H2

(C) H3

(D) H4

Organizing Institute: IIT Guwahati Page 8 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 8 of 40

m
m .co

m .co s e m

se g l a
a
Q.10 As shown in the figure, circle 𝐶1 with center 𝑂1 and radius 𝑟1 touches the square
𝑉𝑊𝑋𝑌 at points 𝑃 and 𝑄 while circle 𝐶2 with center 𝑂2 and radius 𝑟2 touches the
square 𝑉𝑊𝑋𝑌 at points 𝑅 and 𝑆. The two circles touch each other at 𝑇.

̅̅̅̅ = 𝑉𝑊
Given 𝑟1 = 1 cm and 𝑉𝑌 ̅̅̅̅̅ = 4 cm, 𝑟2 = _____ cm.

m
m .co
m .co s e m
s e l a
g l a ag
a

m
m .co
s e
g la
a

m
m 4 − 3√2
.co
(A)

m .co s e m
s e (B) 1 + 2√2
g l a
g la a
a (C) 7 − 4√2

(D) 5 + 3√2

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 9 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 9 of 40

Q.11 – Q.35 Carry ONE mark Each

Q.11 Which one of the following is NOT a type of chain conveyor?

(A) apron conveyor

(B) bucket conveyor

(C) scraper conveyor

(D) screw conveyor

Organizing Institute: IIT Guwahati Page 10 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 10 of 40

m
m .co

m .co s e m

se g l a
a
Q.12 In the P&ID shown below, which one of the following is the function of PAH in the
process?

m
m .co
m .co s e m
s e l a
g l a ag
a

m
.co
s em
a
to maintain a constant pressureginl the vessel by throttling the pump outlet
a
(A)

(B) to alert when high pressure is detected in the tank

(C) to measure the average pressure in the vessel and display it locally

m
(D) to regulate the flow from the vessel to downstream users

m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 11 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 11 of 40

Q.13 A body is placed inside a perfectly black enclosure and is allowed to reach thermal
equilibrium. According to the Kirchhoff’s identity, which one of the following is
equal to the emissivity of the body at a given wavelength?

(A) absorptivity of the body at the same wavelength

(B) reflectivity of the body at the same wavelength

(C) Stefan-Boltzmann constant

(D) zero

Q.14 Which one of the following ratios does Grashof number represent?

(A) buoyancy force to inertia force

(B) buoyancy force to viscous force

(C) viscous force to capillary force

(D) viscous force to inertia force

Organizing Institute: IIT Guwahati Page 12 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 12 of 40

m
m .co

m .co s e m

se g l a
a
Q.15 Consider a closed system of one mole of an ideal gas undergoing a polytropic
process. The process follows 𝑃𝑉 𝑛 = constant, where P is the pressure, V is the
volume and n is a constant. If the process is isobaric, which one of the following is
the value of n?

m
m .co
m .co s e m
(A)
s
0
e l a
g l a ag
(B)
a 1

(C) ∞

(D) the ratio of specific heat capacity at constant pressure to specific heat capacity at
constant volume

m
m .co
s e
g la point?
Q.16 According to the phase rule, which one of the following is the number of degrees of
a
freedom for pure water at its triple

(A) −3

(B) 0
m
m
c. o(C) m.co
m
1
s e
s e g l a
g la a
a
(D) 3

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 13 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 13 of 40

Q.17 An irreversible chemical reaction occurs on a porous catalyst. All the pores are of
same size. In strong pore diffusion regime, the observed activation energy is
120 kJ mol−1 . The activation energy of diffusion is 10 kJ mol−1 . Assuming
Arrhenius temperature dependency for both reaction and diffusion, which one of the
following is the true activation energy (in kJ mol−1 ) of the reaction?

(A) 65

(B) 110

(C) 130

(D) 230

Q.18 In a traditional continuous Kraft (Sulfate) pulping process, consider the following
major steps:

Bleaching (BL), Chipping (CH), Debarking (DE), Digestion (DI), and Pulp
Washing (WA).

Which one of the following is the CORRECT sequence of steps for this process?

(A) DE → BL → WA → DI → CH

(B) DE → CH → DI → WA → BL

(C) DE → CH → WA → DI → BL

(D) DE → BL → WA → CH → DI

Organizing Institute: IIT Guwahati Page 14 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 14 of 40

m
m .co

m .co s e m

se g l a
a
Q.19 For an irreversible reaction containing inerts in the feed, single-pass conversion in
a reactor is 70%. Which one of the following statements is CORRECT?

m
(A)
m
Recycle eliminates the need for a purge stream.
.co
.co s e m
s em l a
ag
(B) Recycle reduces the concentration of inerts in the system.

g la
(C) a Recycle increases the overall conversion.

(D) Recycle decreases the overall conversion.

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 15 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 15 of 40

Q.20 A binary mixture of butane and butadiene is to be separated in an extractive
distillation using furfural. Furfural lowers the activity of butadiene more than it does
for butane. Consider the distillation sequence shown in the figure.

Match the component labels in Group I with chemical species in Group II.

Group I Group II

P. Component X 1. Butane

Q. Component Y 2. Butadiene

R. Component Z 3. Furfural

(A) P-1, Q-2, R-3

(B) P-1, Q-3, R-2

(C) P-2, Q-1, R-3

(D) P-2, Q-3, R-1

Organizing Institute: IIT Guwahati Page 16 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 16 of 40

m
m .co

m .co s e m

se g l a
a
Q.21 A two-dimensional temperature profile is given as 𝑇 = 2𝑥 2 + 3𝑥𝑦 + 𝑦 2 . If 𝒊̂ and 𝒋̂
are the unit vectors along x and y directions, respectively, which one of the following
is the directional derivative of T at the location 𝑥 = 2, 𝑦 = 2?

m
8𝒊̂ + 12𝒋̂ m .co
.co
(A)
e m
em l as
(B)
la s14𝒊̂ + 10𝒋̂
ag
g
a 8𝒊̂ − 12𝒋̂
(C)

(D) 14𝒊̂ − 10𝒋̂

m
c. olim 𝑒cos−𝑥−1
𝑥
Q.22 Which one of the following is the value of ?
em
𝑥→0 𝑥−1

las
ag
(A) −1

(B) 0

(C) 1
m
m
c. o(D) m.co
m
∞
s e
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 17 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 17 of 40

−3 4
Q.23 Which one of the following is the pair of eigenvalues of the matrix [ ]?
4 3

(A) −7, 7

(B) −5, 5

(C) −4, 3

(D) −3, 4

Q.24 Which one of the following is produced by catalytic reforming of straight run
gasoline and naphtha?

(A) diesel oil

(B) furnace oil

(C) high octane gasoline

(D) kerosene

Organizing Institute: IIT Guwahati Page 18 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 18 of 40

m
m .co

m .co s e m

se g l a
a
Q.25 A process exhibits an inverse response to a step input. Which of the following
statements is/are necessarily TRUE about the process?

m
(A)
m
Its transfer function has a positive zero.
.co
.co s e m
s em l a
ag
(B) Its transfer function has a negative zero.

g la
(C) a The initial direction of the step response is opposite to the final steady state value.

(D) The system is unstable due to a zero in the right half of the s-plane.

m
.co
Q.26 Urea has its major use as a solid fertilizer for nitrogen fixation. Which of the
following is/are other application(s) of urea?
e m
las
ag
(A) manufacturing of resins and plastics

(B) melamine production

m
(C) muriatic acid production

m
c. o(D) m.co
m
sulfamic acid production
s e
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 19 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 19 of 40

Q.27 Which of the following statements regarding the heat of reaction is/are CORRECT?

(A) For endothermic reaction, it is positive.

(B) For exothermic reaction, it is negative.

(C) For exothermic reaction, it is positive.

(D) It is the enthalpy change for a process in which stoichiometric quantities of
reactants, at a temperature and pressure, react completely in a single reaction to
form products at the same temperature and pressure.

Q.28 In which of the following condition(s), Bernoulli’s equation is applicable?

(A) incompressible flow

(B) inviscid flow

(C) unsteady flow

(D) flow along a streamline

Organizing Institute: IIT Guwahati Page 20 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 20 of 40

m
m .co

m .co s e m

se g l a
a
Q.29 Which of the following methods for calculating profitability does/do NOT consider
the time value of money?

m
(A)
m
rate of return on investment
.co
.co s e m
s em l a
ag
(B) discounted cash flow rate of return

g la
(C) a payback period

(D) net present worth

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 21 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 21 of 40

Q.30 Consider two successive screen sizes in the Tyler standard screen scale, viz.
150 meshes per inch and 200 meshes per inch. Their linear sizes of the openings are
L150 and L200, respectively. If the value of L200 is 2.9 × 10−3 inch, then the value of
L150 (in inch) is _____ × 10−3 (rounded off to one decimal place).

Q.31 Consider a homogeneous gas phase reaction, A + 2B → 2C + 3D, occurring at
constant temperature and pressure in a varying volume batch reactor. The vessel is
initially charged with 50 moles of A and 150 moles of B. The gases behave ideally.
For complete conversion of A, the ratio of the final volume to the initial volume is
______ (rounded off to one decimal place).

Q.32 Water is discharged from vertical side of a tank through a circular orifice of
diameter 2 cm under laminar flow conditions. The water surface in the tank is
maintained at constant level above the center of the orifice. If the fluid jet has a
diameter of 1.6 cm at its vena contracta, then the coefficient of contraction is
________________ (rounded off to two decimal places).

Organizing Institute: IIT Guwahati Page 22 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 22 of 40

m
m .co

m .co s e m

se g l a
a
Q.33 Consider a non-reactive binary mixture of two ideal gases A and B in an isothermal
horizontal closed tube. Due to the concentration difference at the two ends of the
tube, equimolal counterdiffusion occurs along the axial direction. No concentration
gradients exist in the radial direction. The profile for partial pressure of component
A (𝑝𝐴 ) as a function of axial distance 𝑧 is shown in the figure. The partial pressure
of component B (𝑝𝐵 ) approaches zero at 𝑧 = 0.8 m. At a location 𝑧 = 𝑧1 the partial
m
.co
pressures of the components A and B are equal. The value of 𝑧1 (in m)
m
.co m
is _____ (rounded off to two decimal places).

m s e
s e l a
g l a ag
a

m
m .co
s e
g la
a

An experiment is performed by rolling an unbiased die once. Events A and B are
Q.34
defined as follows:

Event A: The outcome of the rolled die is a prime number.
Event B: The outcome of the rolled die is an odd number less than 4.
o m
m c
. (rounded
m .co e m
The conditional probability of A given B, denoted by P(A|B), is ______
s
s e
off to one decimal place).
g l a
g la Using single step trapezoidal rule, the value of a
a Q.35
0.5
∫ (1 + 16𝑥 − 20𝑥 2 ) 𝑑𝑥
0

is ______ (rounded off to two decimal places).

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 23 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 23 of 40

Q.36 – Q.65 Carry TWO marks Each

Q.36 K value is defined as the ratio of mole fraction of a component in the vapor phase
to that in the liquid phase. The K values of propane and iso-butane at 293 K are
given in the table.

K values
Pressure (kPa) Propane iso-Butane
1100 1.8 0.85
1200 1.6 0.75
1300 1.4 0.65
1400 1.25 0.5
1500 1.1 0.45

Which one of the following is closest to the bubble point pressure (in kPa) of an
equimolar mixture of propane and iso-butane at 293 K?

(A) 1110

(B) 1190

(C) 1310

(D) 1390

Organizing Institute: IIT Guwahati Page 24 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 24 of 40

m
m .co

m .co s e m

se g l a
a
Q.37 Consider a flow with the following velocity field

̂
⃗⃗ = (𝑥 + 𝑦)𝒊̂ + (𝑦 + 𝑧)𝒋̂ + (𝑧 + 𝑥)𝒌
𝑽

̂ are the unit vectors in the x, y and z directions, respectively. Which
where 𝒊̂, 𝒋̂ and 𝒌
one of the following is CORRECT?
m
m .co
.co s e m
s em l a
g la flow is incompressible and irrotational. ag
(A)
a The

(B) The flow is incompressible and rotational.

(C) The flow is compressible and rotational.

m
.co
(D) The flow is compressible and irrotational.

e m
las
ag

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 25 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 25 of 40

Q.38 Vapor pressure of water at various temperature is given in the table.

Temperature (in K) 284 289 294 299 310

Vapor pressure of water (in kPa) 1.28 1.80 2.50 3.40 6.40

An air and water vapor mixture at 100 kPa with a relative humidity of 20% has a
dry-bulb temperature of 310 K. Assume latent heat of vaporization for water is
44 kJ mol−1 and specific heat capacity of the air and water vapor mixture is
0.035 kJ mol−1 K −1. Which one of the following is the closest to its wet-bulb
temperature (in K)?

(A) 284

(B) 294

(C) 310

(D) 321

Organizing Institute: IIT Guwahati Page 26 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 26 of 40

m
m .co

m .co s e m

se g l a
a
Q.39 A volatile organic compound (VOC) is to be adsorbed from air onto a bed of
activated carbon. The equilibrium capacity of activated carbon at the feed
conditions is 0.4 grams VOC per gram of activated carbon. The column contains
4 grams of activated carbon per cm2 of cross-section. The feed rate into the adsorber
column is 0.2 grams VOC cm−2 h−1 . Breakthrough time is defined as the time at
which the concentration at the exit of the bed (𝑐) reaches a value of 0.05𝑐0 , where
m
.co
𝑐0 is the concentration of VOC in the feed. The breakthrough time for the bed is
m
.co
2.1 h. The area under 𝑐⁄𝑐0 curve between the initial and breakthrough times is
e m
m
0.1 h. Which one of the following is the fraction of unused bed at breakthrough?
e l as
l as ag
ag
(A) 0

(B) 0.25

m
.co
(C) 0.50

e m
(D) 0.75
las
ag

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 27 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 27 of 40

Q.40 Consider the following complex numbers

𝑧1 = 𝑟1 (cos 𝜃1 + 𝑖 sin 𝜃1 )
𝑧2 = 𝑟2 (cos 𝜃2 + 𝑖 sin 𝜃2 )
𝜋 𝜋
where 𝑟1, 𝑟2 are real numbers, 0 ≤ 𝜃1 ≤ , 0 ≤ 𝜃2 ≤ , and 𝑖 = √−1
2 2

If |𝑧1 + 𝑧2 | = |𝑧1 | + |𝑧2 |, which one of the following conditions is necessarily
CORRECT?

(A) 𝜋
𝜃1 = 0, 𝜃2 =
2

(B) 𝜋
𝜃1 = ,𝜃 = 0
2 2

(C) 𝑟1 = 𝑟2

(D) 𝜃1 = 𝜃2

Organizing Institute: IIT Guwahati Page 28 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 28 of 40

m
m .co

m .co s e m

se g l a
a
Consider the following curve in polar coordinates.
Q.41
𝑟 = 2 − 2 sin 𝜃

Which one of the following is the area enclosed by the curve for 0 ≤ 𝜃 ≤ 2𝜋 ?

m
m .co
m .co s e m
s e
3𝜋 l a
ag
(A)

g l a
(B) a 4𝜋

(C) 5𝜋

(D) 6𝜋

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 29 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 29 of 40

Q.42 Consider the following homogeneous isothermal liquid-phase parallel reactions
carried out in three reactor configurations (having identical volumes and same
operating temperatures), as shown in the figure.

A + B → D Rate of formation of D: 𝑟𝐷 = 𝑘1 𝐶𝐴 𝐶𝐵
A + B → U Rate of formation of U: 𝑟𝑈 = 𝑘2 𝐶𝐴2 𝐶𝐵
where D is the desired product and U is the undesired product. The inlet
concentrations of A and B are the same in all three configurations
(𝐶𝐴0 = 𝐶𝐵0 = 1 mol L−1). The total molar feed flow rate of A (𝐹𝐴0 ) and that of
B (𝐹𝐵0 ) are the same in all three configurations (𝐹𝐴0 = 𝐹𝐵0 = 10 mol min−1 ). In
configuration I, 𝐹𝐴0 is equally distributed among all the inlets. Similarly, in
configuration III, 𝐹𝐵0 is equally distributed among all the inlets. Assuming plug flow
behavior, at steady state, which one of the following statements is CORRECT?

(A) Configuration I and Configuration III give the same selectivity of the desired
product.

(B) Configuration I gives the highest selectivity of the desired product.

(C) Configuration II gives the highest selectivity of the desired product.

(D) Configuration III gives the highest selectivity of the desired product.

Organizing Institute: IIT Guwahati Page 30 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 30 of 40

m
m .co

m .co s e m

se g l a
a
Q.43 The reaction rate constants of two reactions follow Arrhenius’ law. The activation
energies of Reaction 1 and Reaction 2 are 𝐸1 and 𝐸2 , respectively and 𝐸1 < 𝐸2 .
Assuming same value for the frequency factor for both the reactions, which one of
the following statements is CORRECT?

m
c o m m .co
Reaction 1.and Reaction 2 are less temperature sensitive at lower temperature than se
emtemperature. a
(A)
s g l
la
at higher

g a
(B)
a Reaction 1 and Reaction 2 have the same temperature sensitivity at all temperatures.
(C) Reaction 1 is more temperature sensitive than Reaction 2 at all temperatures.

(D) Reaction 2 is more temperature sensitive than Reaction 1 at all temperatures.

m
m .co
s e
la characteristics has a turndown ratio (ratio of
maximum flow to minimumgcontrollable flow) of 50. The flow rate through the
Q.44 A control valve with hyperbolic
a 3 −1
valve at 70% open is 5 m s . Assuming constant fluid density and pressure drop
across the valve, which one of the following is the flow rate (in m3 s −1 ) through the
valve at 30% open?

m
.co
(A) 1.1
m
c. o(B) s e m
e m 2.2
l a
las ag
ag (C) 3.3

(D) 4.4

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 31 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 31 of 40

Q.45 The gross energy requirement, to reduce a very large feed of coal to such a size that
80% of the product passes through a 100 µm screen, is 13 kWh per ton of feed. In a
process, 250 tons h−1 of coal is crushed. The range of feed sizes is such that 80%
of the feed passes through an opening of 100 mm. The product size range is to be
such that 80% of the product passes through an opening of 25 mm. According to the
Bond’s law, which one of the following is the power consumption (in kW)?

(A) 12.8

(B) 25.7

(C) 51.4

(D) 102.7

Q.46 In a certain project, 15% of the total investment is the working capital. The minimum
acceptable rate of return is 4.95% and the period of evaluation is 15 years. Which
one of the following is the maximum acceptable project payback period (in years)?

(A) 5

(B) 8

(C) 12

(D) 15

Organizing Institute: IIT Guwahati Page 32 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 32 of 40

m
m .co

m .co s e m

se g l a
a
Q.47 A continuous distillation column is used to separate an equimolar mixture of
diethylamine (DEA) and methanol. The feed enters the column as saturated liquid
at a flow rate of 30 mol s −1. It is desired to obtain 92 mol% DEA as distillate. The
rate of withdrawal of the distillate from the column is 10 mol s −1. The equilibrium
curve for the conditions in the column is given below. The latent heat of vaporization
of the reboiler contents is 35 kJ mol−1 . Neglect heat loss to the surroundings and
m
.co
assume constant molal overflow. Which one of the following is the minimum
m
.co m
reboiler heat duty (in kW)?

m s e
s e l a
g l a ag
a

m
m .co
s e
g la
a

m
.co
(A) 350
m
c. o(B) s e m
e m 700
l a
las ag
ag (C) 1120

(D) 1470

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 33 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 33 of 40

Q.48 A gas stream with 2.01 mol % ammonia is to be scrubbed in a counter-current
isothermal packed bed absorber using pure water to reduce its concentration to
0.01 mol %. Assume that dilute conditions apply, operating line is linear and the
mass transfer coefficients are constant throughout the column. The liquid and the
gas flows inside the absorber (in kmol m−2 h−1 ) are 1000 and 200, respectively.
The equilibrium relationship is 𝑦 = 0.9 𝑥, where, 𝑦 is the mole-fraction of ammonia
in the gas phase and 𝑥 is that in the liquid. Under these conditions, the height of
overall gas transfer unit (𝐻𝑡𝑂𝐺 ) is 0.8 m and the number of overall gas transfer units
(𝑁𝑡𝑂𝐺 ) is given by the following integral.
𝑦2
𝑑𝑦
𝑁𝑡𝑂𝐺 = ∫ ∗
𝑦1 𝑦 − 𝑦

The integration is performed between the two ends of the column, and 𝑦 ∗ is the
equilibrium mole fraction in the gas phase, corresponding to the composition of the
liquid at corresponding location. Which one of the following is the minimum length
of the packing (in m) necessary to achieve the desired scrubbing?

(A) 4.2

(B) 5.0

(C) 6.2

(D) 7.7

Organizing Institute: IIT Guwahati Page 34 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 34 of 40

m
m .co

m .co s e m

se g l a
a
Q.49 Laboratory filtration is conducted at constant pressure drop of 200 kPa on a slurry
of CaCO3 in water at room temperature. The time taken to collect filtrate is shown
in the table.

Filtrate volume Time
collected (in m3 ) (in s)
m
.co
1 × 10−3 40

o m 2 × 10−3 100
m
. c s e
emis the filter medium resistance (in m )? a
−3
2
10
l
The filter area is 0.05 m and viscosity of filtrate is Pa s. Which one of the

as
following
l
−1

a g
ag
(A) 3 × 10−11

(B) 3 × 10−8

m
(C) 3 × 108
m .co
s e
(D) 3 × 1011
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 35 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 35 of 40

Q.50 Consider three identical non-interacting first order processes in series, each having
unit gain and a time constant of 2 min. Tuning of proportional controller using
closed loop Ziegler-Nichols technique is considered. Which one of the following is
the ultimate period of sustained cycling (in min per cycle)?

(A) 4√3𝜋

(B) √3𝜋
4

(C) 4𝜋
√3

(D) 𝜋
4√3

Q.51 A thermometer initially at a steady temperature of 30 ℃ is inserted in a water bath
maintained at 90 °C. The initial rate of temperature rise of the thermometer is
2 ℃ s −1. Assuming first order behavior, the thermometer reading (in ℃) after one
minute is ______ (rounded off to one decimal place).

Q.52 In a double pipe cocurrent heat exchanger, operating at steady state, oil (specific
heat capacity = 2100 J kg −1 ℃−1 ) entering at 7 kg s−1 at 100 ℃ is used to heat
water (specific heat capacity = 4200 J kg −1 ℃−1 ) flowing at 3.5 kg s −1 from 20 ℃
to 50 ℃. If the overall heat transfer coefficient is 291 W m−2 ℃−1 , the required heat
transfer area (in m2) is _____ (rounded off to one decimal place).

Organizing Institute: IIT Guwahati Page 36 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 36 of 40

m
m .co

m .co s e m

se g l a
a
Q.53 A pipe with outer diameter of 0.02 m, carries hot water. The temperature at the outer
surface of the pipe is 70 ℃. This pipe is covered with two concentric layers of
insulation, each having a thickness of 0.01 m. The first layer (adjacent to the pipe)
is made up of felt material (thermal conductivity 𝑘𝑓 = 0.12 W m−1 ℃−1 ), and the
next layer is made up of asbestos (thermal conductivity 𝑘𝑎𝑠 = 0.15 W m−1 ℃−1 ).
The insulated pipe is exposed to ambient air at 20 ℃. The convection heat transfer
m
.co
coefficient at the outer insulation layer is 3 W m−2 ℃−1 . At steady state, neglecting
m
.co m
heat transfer due to radiation, the heat loss at the outer insulation layer (in W m−1)
s e
em
is _____ (rounded off to two decimal places).
s l a
la is formed by the following gas phase homogeneous reaction:
Q.54 gMethanol ag
a
CO (g) + 2H2 (g) ⇋ CH3 OH (g)

The standard Gibbs free energies of formation at 298 K for CO and CH3OH are
−137 kJ mol−1 and −162 kJ mol−1 , respectively. The value of universal gas
constant is 8.314 J mol−1 K −1 . The equilibrium constant for the given reaction at
298 K is _____ × 104 (rounded off to one decimal place).

m
Q.55
m .co
A first-order homogeneous liquid-phase reaction (A→B) occurs in an adiabatic,
ideal mixed flow reactor operating at steady state. The volumetric flow rate of the
s e
feed is 4 L min−1 and volume of the reactor is 20 L. At the reactor temperature of
la
500 K, the reaction rate constant is 1 min−1, and heat of reaction is
g
a
−20 kcal mol−1 . The average heat capacity of the feed as well as the reaction
mixture in the temperature range of interest is 0.3 kcal mol−1 K −1.

At the inlet, the feed temperature (in K) is _________ (rounded off to one decimal
place).

Q.56 A first-order homogeneous liquid-phase reaction (A→B) occurs in a non-ideal
isothermal reactor operating at steady state. The variance (𝜎 2 ) of residence time
m
.co
distribution (RTD) from a pulse tracer experiment is 4 min2. The volumetric flow
m
.co
rate of the feed is 5 L min−1 and volume of the reactor is 25 L. The reaction rate
constant is 0.4 min−1. Based on the tanks-in-series model, the conversion (in %) is e m
e m l as
s
_______ (rounded off to one decimal place).

la ag
ag

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 37 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 37 of 40

Q.57 A feed containing 10 mol % propylene, 15 mol % ammonia and rest air is charged
into a reactor to produce acrylonitrile (C3H3N) according to the following reaction.

2C3H6 + 2NH3 + 3O2 → 2C3H3N + 6H2O
Assume, air contains 80 mol % N2 and 20 mol % O2.

If the conversion of the limiting reactant is 30%, the composition of
C3H3N (in mol %) in the product stream is ___________(rounded off to two decimal
places).

Q.58 A gas mixture of 50 wt. % argon and 50 wt. % helium flowing through a horizontal
tube of uniform diameter at a rate of 1 kg s −1 is heated from 300 K to 400 K at
1 bar. Neglect shaft work, and changes in kinetic as well as potential energies
between the inlet and the outlet. Assume the mixture exhibits ideal gas behavior.
The specific enthalpies of the components are given in the following table.

Specific enthalpy (kJ kg −1)
Component
at 300 K at 400 K
Argon 348 400
Helium 1574 2092

At steady state, the heat input required (in kW) is ___________ (rounded off to the
nearest integer).

Q.59 When a cylindrical capillary glass tube, open at both ends, is vertically inserted in
a pool of water, the water level in the tube rises to 7 cm relative to the water level
outside the tube. Consider that the surface tension of water is 0.07 N m−1 and that
the contact angle of water on glass is 0°. The density of water is 1000 kg m−3 , and
the local acceleration due to gravity is 10 m s −2. The diameter of the capillary tube
(in μm) is __________ (rounded off to the nearest integer).

Q.60 Consider a two-dimensional, steady, laminar flow of an incompressible fluid with
zero pressure gradient, over a thin horizontal flat plate of length 2 m. The free stream
velocity is 1 m s−1 . A boundary layer thickness of 1 mm is observed at a distance
of 0.25 m from the leading edge of the plate. At 1 m from the leading edge, the
boundary layer thickness (in mm) is _________ (rounded off to the nearest integer).

Organizing Institute: IIT Guwahati Page 38 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 38 of 40

m
m .co

m .co s e m

se g l a
a
Q.61 The flooding velocity curves for two different structured packings are shown in the
figure. The ratio of mass velocities of liquid (𝐺𝑥 ) to that of the gas (𝐺𝑦 ) is 1.27. The
density of the liquid (𝜌𝑥 ) is 1200 kg m−3 and that of the gas (𝜌𝑦 ) is 1.2 kg m−3. For
both the packings, the allowable superficial vapor velocity is 60% of flooding
velocity (𝑢0,𝐹 ). The ratio of allowable mass velocity of the vapor in packing P to that
in packing Q is _____________ (rounded off to one decimal place).
m
m .co
m .co s e m
s e l a
g l a ag
a

m
m .co
s e
g la
a
Q.62 Consider a differential equation:

𝑑2𝑦 𝑑𝑦
𝑥2 2
+ 3𝑥 − 3𝑦 = 0
𝑑𝑥 𝑑𝑥

m
.co
𝑦=3
m
.co
𝑑𝑦 } 𝑎𝑡 𝑥 = 1

m 𝑑𝑥
= −5
s em
s e g la
g la a places).
a The value of y at 𝑥 = 2 is ______ (rounded off to two decimal

m .
.co s e m
s em l a
la
Organizing Institute: IIT Guwahati

g
Page 39 of 40
ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 39 of 40

Q.63 The data given in the table are fitted to the equation 𝑦 = 𝑚𝑥 using the method of
least squares. The value of 𝑚 is ______ (rounded off to one decimal place).

𝑥 1 2 3 4
𝑦 2 6 7 10

Q.64 Cyclohexane (C6H12) is produced from benzene (C6H6) and hydrogen (H2) according
to the following reaction.
C6 H6 + 3H2 ⟶ C6 H12
Consider the process flow diagram shown in the figure.

In this process, the overall and single-pass conversions are 90% and 25%,
respectively. The recycle stream contains 25 mol % C6H6 and 75 mol % H2. If the
fresh feed contains 25% excess H2, at steady state, the ratio of the molar flow rate of
recycle stream to that of the fresh feed is _________ (rounded off to one decimal
place).

Q.65 The velocity profile for a fully developed laminar flow of an incompressible
Newtonian fluid, at steady state, through a horizontal infinitely wide and long slit of
gap 0.01 m is given by the following equation.

𝑢(𝑦) = 7.5 − 3 × 105 𝑦 2

where 𝑦 is the vertical distance measured from the center of the slit. The average
velocity of the fluid (in m s−1 ) is ____________ (rounded off to the nearest integer).

Organizing Institute: IIT Guwahati Page 40 of 40

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 40 of 40