AP PGECET 2024 Chemical Engineering Question Paper with Answer Key PDF

Question 1:

Which of the following states that the total pressure exerted by a gaseous mixture is equal to the sum of the partial pressures?

• (1) Amagat’s law
• (2) Raoult’s law
• (3) Dalton’s law
• (4) Avogadro’s law

If air has 21% and 79% of Oxygen and Nitrogen by volume respectively. What is the average molecular weight?

• (A) \( 29.3 \)
• (B) \( 29 \)
• (C) \( 28.84 \)
• (D) \( 28 \)

An organic compound is found to contain \( \mathrm{C} = 54.5% \), \( \mathrm{O} = 36.4% \), and \( \mathrm{H} = 9.1% \) by weight. Its empirical formula is:

• (1) \(\mathrm{CHO}_2\)
• (2) \(\mathrm{C_2H_4O}\)
• (3) \(\mathrm{C_2H_6O}\)
• (4) \(\mathrm{C_3H_4O}\)

Cox charts are plotted

• (A) Logarithm of vapour pressure of a substance versus logarithm of partial pressure of the reference substance
• (B) Logarithm of vapour pressure of a substance versus logarithm of the vapour pressure of reference substance
• (C) Logarithm of vapour pressure of a substance versus temperature
• (D) Logarithm of vapour pressure of a substance versus partial pressure

The number of degrees of freedom for a mixture of liquid water and liquid toluene (immiscible in water) in equilibrium with their vapours is:

• (1) 3
• (2) 2
• (3) 1
• (4) 0

The solubility of sodium chloride in water at 290K is 35.8 kg/100 kg water. What is the mass fraction of sodium chloride in the solution?

• (1) 0.264
• (2) 0.358
• (3) 0.642
• (4) 0.736

The ratio of moles of the reactant converted to the desired product and moles of the reactant converted to undesired product is called as:

• (1) Conversion
• (2) Selectivity
• (3) Reaction yield
• (4) Plant yield

A recycle ratio is defined as:

• (1) Recycle stream/fresh feed stream
• (2) Recycle stream/gross feed stream
• (3) Gross feed stream/recycle stream
• (4) Fresh feed stream/recycle stream

In which of the following process involving an ideal gas, the change in internal energy and the change in enthalpy would be zero?

• (1) Isobaric process
• (2) Isothermal process
• (3) Adiabatic process
• (4) Polytropic process

The Vander Waals equation of state is given by:

• (1) \( P = \frac{RT}{(v - b)} - \frac{a}{T^{0.5} v (v + b)} \)
• (2) \( P = \frac{RT}{(v - b)} - \frac{a}{v^2} \)
• (3) \( P = \frac{RT}{(v - b)} - \frac{{a'}{T}}{v(v + b)} \)
• (4) \( P = \frac{RT}{(v - b)} - \frac{a \alpha}{v(v + b) + b(v - b)} \)

Entropy of a system is:

• (1) A measure of disorder of the system
• (2) A measure of orderly behaviour of the system
• (3) Independent of Temperature
• (4) Independent of Pressure

When the reactants and products are at their standard states, the change in enthalpy accompanying the formation of 1 mole of a substance from the constituent elements is termed as:

• (1) The standard heat of reaction
• (2) The standard heat of formation
• (3) The standard heat of combustion
• (4) The standard heat of accumulation

The Carnot cycle consists of an alternate series of

• (1) Two reversible isothermal processes and two reversible adiabatic processes
• (2) Two reversible isobaric processes and two reversible adiabatic processes
• (3) Two reversible isothermal processes and two reversible isobaric processes
• (4) Two reversible isothermal processes and two polytropic processes

For an ideal gas mixture, the fugacity of a component is equal to

• (1) Vapour pressure of that component
• (2) Partial pressure of the component
• (3) The total pressure of the mixture
• (4) The vapour pressure of the component at STP

For an ideal gas mixture undergoing a reversible gaseous phase chemical reaction, the equilibrium constant:

The Gibbs free energy change (\(\Delta G^\circ\)) and equilibrium constant (K) for a chemical reaction are related by

• (1) \(\Delta G^\circ = RT \ln K\)
• (2) \(\Delta G^\circ = T \ln K\)
• (3) \(\Delta G^\circ = RTK\)
• (4) \(\Delta G^\circ = -RT \ln K\)

An ideal fluid is the one which:

The flow of incompressible fluids without the presence of shear is referred to as

• (1) Potential flow
• (2) Turbulent flow
• (3) Laminar flow
• (4) Fully developed flow

The Bernoulli equation states that in a steady irrotational flow of an incompressible fluid,

• (1) The total potential energy at any point is constant
• (2) The total kinetic energy at any point is constant
• (3) The total energy at any point is constant
• (4) The total pressure energy at any point is constant

When the flow of a fluid through a circular pipe, the friction factor is

• (1) \( f = \frac{16}{N_{Re}} \)
• (2) \( f = \frac{24}{N_{Re}} \)
• (3) \( f = 0.079 N_{Re}^{-1/2} \)
• (4) \( f = 0.079 N_{Re}^{-1/4} \)

Pitot tube is used for measuring:

Kozney Carman equation is used for finding

• (1) Volumetric flow rate through a pipe line
• (2) Velocity of fluids through a duct
• (3) Pressure drop through a packed bed
• (4) Pressure drop through a fluidized bed

In which of the following pumps, the displacement of fluid is by rotating action

• (1) Centrifugal pump
• (2) Gear pump
• (3) Plunger pump
• (4) Piston pump

Which of the following happens when the gas velocity increases in fluidization?

• (1) Bulk density of the bed increases and fluidization become less aggressive
• (2) Bulk density of the bed decreases and fluidization become less aggressive
• (3) Bulk density of the bed increases and fluidization become more aggressive
• (4) Bulk density of the bed decreases and fluidization become more aggressive

100-mesh screen means

• (1) 100 little square openings per one linear cm of screen
• (2) 100 little square openings per one linear mm of screen
• (3) 100 little square openings per one linear inch of screen
• (4) 100 little square openings per one linear feet of screen

The work required for crushing a given material is proportional to the logarithm of the ratio between the initial and final diameters is a statement of:

In a ball mill, centrifugal force will be exactly balanced by the weight of the ball when mill runs at

• (1) Minimum speed
• (2) Maximum speed
• (3) Critical speed
• (4) Optimum speed

The mass of material that can be fed per unit time to a unit area of the screen is called as

• (1) Effectiveness of the screen
• (2) Capacity of the screen
• (3) Ability of the screen
• (4) Productivity of the screen

Which of the following is a process of gravity concentration where solids are separated based upon the differences in the behavior of particles through a moving fluid which in turn, depends upon densities/specific gravities.

• (1) Classification
• (2) Sedimentation
• (3) Centrifugation
• (4) Jigging

The filter aid is a granular or fibrous material and is used to

• (1) Increase the cake resistance
• (2) Increase the cake porosity
• (3) Increase the pressure drop across the cake
• (4) Increase the filter medium resistance

A fluid energy mill is used for:

In a batch thickener, the rate of sedimentation can be artificially increased by

• (1) The addition of coagulating agents
• (2) Cooling the suspension to room temperature
• (3) Promoting the free settling
• (4) Controlling the flow rate

The critical radius of insulation is

• (1) \( \frac{The thermal conductivity of an insulating material}{Heat transfer coefficient at the outer surface of insulation} \)
• (2) \( \frac{The thermal conductivity of metal to be insulated}{Heat transfer coefficient at the outer surface of insulation} \)
• (3) \( \frac{The thermal conductivity of an insulating material}{Heat transfer coefficient at the inside surface of insulation} \)
• (4) \( \frac{The thermal conductivity of metal to be insulated}{Heat transfer coefficient at the inside surface of insulation} \)

The Peclet number is defined as the product of

• (1) The Reynolds number and Graetz number
• (2) The Prandtl number and Nusselt number
• (3) The Reynolds number and Prandtl number
• (4) The Reynolds number and Nusselt number

Ratio of emissive power of a body to the emissive power of a perfectly black body, is known

• (1) Emissivity
• (2) Absorptivity
• (3) Transmissivity
• (4) Reflectivity

In a shell and tube heat exchanger, steam is condensing on the shell side and a cold fluid is flowing through the tubes in the turbulent flow region, then the Wilson plot is used to:

In a heat exchanger, for the same terminal temperatures, the logarithmic mean temperature difference for counter flow is

• (1) Appreciable greater than that for co-current flow
• (2) Appreciable lower than that for co-current flow
• (3) Almost equal to that for co-current flow
• (4) Appreciable lower than that for cross flow

Dropwise condensation,

• (1) Requires smooth, clean uncontaminated surfaces
• (2) Is stable and easy to maintain
• (3) Have higher heat transfer coefficients
• (4) Have lower heat transfer coefficients

As per the Stefan-Boltzmann law the total energy emitted by a black body is directly proportional to

• (1) The third power of its absolute temperature
• (2) The fourth power of its absolute temperature
• (3) The fifth power of its absolute temperature
• (4) The sixth power of its absolute temperature

In shell and tube heat exchanger, external cleaning of the tubes is easy in case of

• (1) Equilateral triangular pitch arrangement of tube layout
• (2) Right angle triangular pitch arrangement of tube layout
• (3) Square pitch arrangement of tube layout
• (4) Hexagonal pitch arrangement of tube layout

Use of multiple effect evaporator results in:

The heat flux in the nucleate boiling regime is proportional to

• (1) \((\Delta T)^2\)
• (2) \((\Delta T)^4\)
• (3) \((\Delta T)^3\)
• (4) \(\sqrt{\Delta T}\)

The steady state gas phase reaction 3A + B \(\rightarrow\) C + 2D takes place on a catalyst surface. What will be the value of the flux ratio \( N_A / N_D \)?

• (1) -2
• (2) -0.5
• (3) -1.5
• (4) 2

Lewis number is the ratio of

• (1) Thermal diffusivity to mass diffusivity
• (2) Mass diffusivity to momentum diffusivity
• (3) Mass diffusivity to thermal diffusivity
• (4) Momentum diffusivity to thermal diffusivity

The penetration theory relates average mass transfer coefficient (\( k \)) with diffusivity (\( D \))

• (1) \( k \propto D \)
• (2) \( k \propto \sqrt{D} \)
• (3) \( k \propto D^{1.5} \)
• (4) \( k \propto D^2 \)

The absorption factor can be increased by:

A plate is called a theoretical plate when

• (1) The vapour and liquid leaving the plate are in equilibrium
• (2) The vapour and liquid entering the plate are in equilibrium
• (3) The vapour leaving the plate is in equilibrium with the liquid entering the plate
• (4) The liquid leaving the plate is in equilibrium with the vapour entering the plate

If reflux in a distillation column is 100 mol/hr and the overhead product rate is 50 mol/hr, the reflux ratio is

• (1) 0.5
• (2) 2
• (3) 50
• (4) 150

At a given temperature, the humid volume is

• (1) Linear function of humidity
• (2) Inverse function of humidity
• (3) Square function of humidity
• (4) No specific function of humidity

In liquid-liquid extraction, if the selectivity is unity, then

• (1) Separation of the components is most effective
• (2) No separation is possible
• (3) Amount of solvent required is minimum
• (4) Solvent flow rate should be very high

Higher temperature increases the rate of leaching in a solid-liquid system due to:

Moisture in a solid exerting an equilibrium vapour pressure equal to that of the pure liquid at that temperature is

• (1) Bound moisture
• (2) Unbound moisture
• (3) Critical moisture
• (4) Equilibrium moisture

In case of adsorption hysteresis, the desorption equilibrium pressure is

• (1) Always lower than that obtained during adsorption
• (2) Always higher than that obtained during adsorption
• (3) Same as that obtained during adsorption
• (4) Can be either higher or lower than that obtained during adsorption

Flooding in a distillation column is detected by a sharp

• (1) Increase in Murphree plate efficiency
• (2) Increase in pressure drop
• (3) Decrease in pressure drop
• (4) Decrease in liquid holdup in the column

The activation energy at high temperatures is lower than at lower temperatures, which represents

• (1) Diffusion regime
• (2) Reaction regime
• (3) Kinetic regime
• (4) Intermediate regime

A reaction is of zero order when the rate of reaction is

• (1) Directly proportional to the concentration of reactant
• (2) Inversely proportional to the concentration of reactant
• (3) Independent of the concentration of reactant
• (4) Independent of temperature and pressure

The most suitable reactor to carry out an auto-thermal reaction is a:

For a steady-state mixed reactor the space-time is equivalent to the holding time for

• (1) Constant fluid density systems
• (2) Variable fluid density systems
• (3) Non-isothermal gas reactions
• (4) Gas reactions with changing number of moles

For identical feed comp., flow rate, conversion and for all positive reaction orders the ratio of the volume of mixed reactor to the volume of plug flow reactor

• (1) Is independent of the order of reaction
• (2) Increases with increase in the order of reaction
• (3) Decreases with increase in the order of reaction
• (4) Increases with increase in the percentage of conversion

In a semi-batch reactor

• (1) Rate of reaction can be controlled
• (2) Maximum conversion can be controlled
• (3) Both the reactants flow counter-currently
• (4) Residence time is constant

The best combination of reactors for an exothermic reaction is:

If the conversion of a first-order liquid phase reaction occurring in a CSTR is 75%, molar feed rate is 5 mol/min, the rate of the reaction is 5 \(\frac{mol}{litre \cdot min}\) then the volume of the reactor (in litre) is?

• (1) 0.33
• (2) 0.4
• (3) 0.75
• (4) 0.5

If \( \tau = 5 \) s, first order rate constant, \( k = 0.25 \) sec\(^{-1}\) and the number of tanks, \( N \) is 5, then the conversion is

• (1) 87.45%
• (2) 33%
• (3) 75%
• (4) 67.2%

Which of the following is true for gas-phase reactions?

• (1) Decrease in moles of the product increases the volume of the reaction mixture
• (2) Increase in moles of the product does not affect the volume of the reaction mixture
• (3) Increase in moles of the product increases the volume of the reaction mixture
• (4) Increase in moles of the product decreases the volume of the reaction mixture

Which of the following represents heterogeneous catalytic reaction?

• (1) Reduction of iron ore
• (2) Ammonia synthesis
• (3) Burning of coal
• (4) Roasting of ores

What is the activity of a catalyst when a time \( t = 0 \)?

If an instrument produces the same reading at different times for the same variation in the measured variable, then it is said to

• (1) Have no hysteresis
• (2) Have no accuracy
• (3) Have no dead zone
• (4) Have no drift

Which of the following pressure gauge operation depends on the variation of the thermal conductivity of a gas at low pressure,

• (1) Bourdon tube gauge
• (2) Hydrostatic gauge
• (3) Pirani gauge
• (4) McLeod gauge

Which of the following measuring device is not suitable for the measurement of the rate of flow of liquids

• (1) Nutating-Disc Meter
• (2) Hot-Wire Anemometer
• (3) Laser-Doppler Anemometer
• (4) Venturi Meter

Bourdon gauges are used for measurement of pressures

• (1) Local atmospheric pressures
• (2) Local absolute pressures
• (3) Low range vacuum pressures
• (4) Large range gauge pressures

If initial conditions for a system are inherently zero, what does it physically mean?

If the system is stable, the response is smooth and non-oscillatory (damping coefficient, \(\xi > 1\)), the response is referred to as

• (1) Overdamped
• (2) Critically damped
• (3) Underdamped
• (4) Undamped

Response of a linear control system for a change in set point is called

• (1) Frequency response
• (2) Transient response
• (3) Servo problem
• (4) Regulatory problem

Which of the following controllers has more oscillatory behaviour in response?

• (1) P-controller
• (2) PI-controller
• (3) PD-controller
• (4) PID-controller

A servo control loop responds for

• (1) Load changing
• (2) Set point changing
• (3) Both load and set point changing
• (4) Neither load nor set point changing

In a Second-order system of under-damped case, the decay ratio and overshoot are related as:

Bode diagram is generated from output response of the system subjected to _____________________ input

• (1) Impulse
• (2) Step
• (3) Ramp
• (4) Sinusoidal

Routh test

• (1) Criterion provides information about the actual location of roots
• (2) Cannot be used to test the stability of a control system containing transportation lag
• (3) Criterion is not applicable to systems with polynomial characteristic equation
• (4) Cannot determine as to how many roots of the characteristic equation have positive real roots

Main function of baffles on the shell side of a heat exchanger is to

• (1) Decrease the pressure drop
• (2) Reduce the scale deposit
• (3) Hold the tubes in position
• (4) Create turbulence

In which of the following type of heat exchanger the heat exchange between the two fluids occur by their complete physical mixing?

• (1) Direct contact heat exchanger
• (2) Indirect heat exchanger
• (3) Recuperator
• (4) Regenerator

In a multistage compressor, intercooling is done to:

A specific advantage of using steam as a heating medium in exchangers is its

• (1) Inexpensiveness
• (2) High value of latent heat
• (3) High film coefficient
• (4) Non-corrosive condensate

The number of bubble caps to be used per tray is determined from

• (1) The vapour load
• (2) The liquid load
• (3) Tray diameter
• (4) Allowable gas velocity

In the tray distillation column, flooding determines

• (1) Maximum vapor flow allowed
• (2) Maximum pressure allowed
• (3) Minimum vapor flow
• (4) Minimum pressure allowed

Liquid remaining in unit volume of bed after bed is drained is called as

• (1) Final holdup
• (2) Total holdup
• (3) Static holdup
• (4) Dynamic holdup

Which is the suitable contacting equipment for gas-liquid operations involving liquids with dispersed solids?

If an amount \(R\) is paid at the end of every year for '\(n\)' years, then the net present value of the annuity at an interest rate of '\(i\)' is

• (1) \(R[\{(1 + i)^n - 1\}/i]\)
• (2) \(R[\{(1 + i)^n - 1\}/\{i(1 + i)^n\}]\)
• (3) \(R(1 + i)^n\)
• (4) \(R/(1 + i)^n\)

Which of the following is a component of working capital investment?

• (1) Utilities plant
• (2) Maintenance and repair inventory
• (3) Process equipment
• (4) Depreciation

Operating profit of a chemical plant is equal to

• (1) Profit before interest and tax
• (2) Profit after tax plus depreciation
• (3) Net profit and tax
• (4) Profit after tax

Which of the following methods of depreciation calculations results in book values greater than those obtained with straight line method?

• (1) Multiple straight-line method
• (2) Sinking fund method
• (3) Declining balance method
• (4) Sum of the years digit method

Thermal diffusivity of a material (\( \alpha \)) is defined as:

The catalyst used in the low-pressure Ziegler process for polyethylene manufacture _____________________

• (1) Is Nickel
• (2) Consists of aluminium triethyl combined with titanium tetrachloride
• (3) Consists of aluminium chloride combine with titanium dioxide
• (4) Is vanadium pentoxide

The major chemical recovered from the black liquor in Kraft Pulp Process is

• (1) Sodium sulphate
• (2) Sodium carbonate
• (3) Sodium hydroxide
• (4) Sodium bicarbonate

Each term of the Bernoulli's equation written in the form \(\frac{p}{\rho} + \frac{g}{g_c}(Z) + \frac{v^2}{2g_c} = Constant\), represents the total energy per unit

• (1) Mass
• (2) Volume
• (3) Specific weight
• (4) Specific volume

What is the disadvantage of Solvay process?

• (1) Higher salt consumption
• (2) No co-products to dispose
• (3) Use of low-grade brine
• (4) Less electric power

What is undesirable in urea production?

Washing soda is

• (1) \(Na_2CO_3\)
• (2) \(Na_2CO_3.H_2O\)
• (3) \(Na_2CO_3.10H_2O\)
• (4) \(NaHCO_3\)

Tetrafluoroethylene is known as

• (1) Perspex
• (2) Nylon-66
• (3) Polyester
• (4) Teflon

Oils and fats are

• (1) Higher alcohols
• (2) Esters of higher acids
• (3) Alkaloids
• (4) Carbohydrates

The monometallic catalyst used in the catalytic reforming of naphtha is

• (1) Platinum
• (2) Nickel
• (3) Molybdenum
• (4) Cobalt

What happens in a reversible adiabatic expansion process?

Economy of a multiple effect evaporator is not influenced much by the

• (1) Boiling point elevations
• (2) Temperature of the feed
• (3) Rate of heat transfer
• (4) Ratio of the weight of thin liquor to thick liquor

The terminal velocity of a small sphere settling in a viscous fluid varies as the

• (1) First power of its diameter
• (2) Inverse square of its diameter
• (3) Inverse of the fluid viscosity
• (4) Square of the difference in specific weight of solid and fluid

Water hammer is caused in steam carrying pipelines, because of

• (1) Partial condensation of steam
• (2) Vibration of pipeline
• (3) High degree of super heat of steam
• (4) Its exposure to torrential rain

Floating head heat exchangers are used for the

• (1) Heat transfer between corrosive fluids
• (2) Cases where temperature difference between the shell and the tubes is more (>50°C)
• (3) Co-current heat transfer systems
• (4) Counter-current heat transfer systems

Rate of a chemical reaction is not influenced by the:

A batch of material is dried under constant drying conditions. When drying is taking place from all the surfaces, the rate of drying during the constant rate period is

• (1) Directly proportional to the solid thickness
• (2) Inversely proportional to the solid thickness
• (3) Independent of solid thickness
• (4) Directly proportional to the square of solid thickness

The hydrodynamic and thermal boundary layers will merge when

• (1) Prandtl number is one
• (2) Schmidt number tends to infinity
• (3) Nusselt number tends to infinity
• (4) Archimedes number is greater than 10,000

Find \(x, y, z\) and \(w\) given that \(3 \begin{bmatrix} x & y
z & w \end{bmatrix} = \begin{bmatrix} x & 5
-1 & 2w \end{bmatrix} + \begin{bmatrix} 6 & x+y
z+w & 5 \end{bmatrix}\)

• (1) \(x = 3,\ y = 4,\ z = 3,\ w = 5\)
• (2) \(x = 3,\ y = 4,\ z = 5,\ w = 2\)
• (3) \(x = 2,\ y = 4,\ z = 2,\ w = 5\)
• (4) \(x = 3,\ y = 4,\ z = 2,\ w = 5\)

Find the largest eigenvalue of the matrix \(\begin{bmatrix} 5 & 4
1 & 2 \end{bmatrix}\)

• (1) 1
• (2) 6
• (3) 2
• (4) 3

Evaluate the limit: \[ \lim_{x \to 0} \left( x - \sin x \right) \left( \frac{1}{x} \right) \]

• (1) 0
• (2) 1
• (3) 2
• (4) 3

The mean of a binomial distribution is 5, then its variance is

• (1) \(>\) 5
• (2) 5
• (3) \(<\) 5
• (4) 25

General solution of \((D^2 - 5D + 6)y = 0\) is \(y(x) =\)

• (1) \(c_1 e^{-3x} + c_2 e^{2x}\)
• (2) \(c_1 e^{3x} + c_2 e^{-2x}\)
• (3) \(c_1 e^{3x} + c_2 e^{2x}\)
• (4) \(c_1 e^{-3x} + c_2 e^{-2x}\)

Integrating factor of the linear differential equation \(\frac{dy}{dx} + \frac{2y}{x} = x \log x\) is

• (1) \(x\)
• (2) \(x^2\)
• (3) \(x^3\)
• (4) \(x^4\)

In the Taylor series expansion of \(e^x\) about \(x = 2\), the coefficient of \((x - 2)^4\) is

• (1) \(\frac{1}{4!}\)
• (2) \(\frac{2^4}{4!}\)
• (3) \(\frac{e^2}{4!}\)
• (4) \(\frac{e^4}{4!}\)

The Laurent series of \( f(z) = \frac{z}{(z^2+1)(z^2+4)} \) for \( |z| < 1 \) is:

Let E and F be the events of a sample space S of an experiment, if \( P(S/F) = P(F/F) \), then \( P(S/F) \) is equal to:

• (1) 0
• (2) -1
• (3) 1
• (4) 2

If \(p = \frac{1}{8}; n = 640; q = \frac{7}{8}\), then variance Binomial Distribution

• (1) 0.07
• (2) 0.7
• (3) 7.0
• (4) 70.0

The function \(f(x,y) = x^2 + y^2 - xy - x - y + 5\) has

• (1) Maximum at (1,1)
• (2) Saddle point at (1,1)
• (3) Minimum at (1,1)
• (4) Minimum at (1,2)

From the given data value of \(\int_{1}^{2} \frac{1}{x} dx\) using Simpson’s 1/3rd rule is

• (1) 0.06932
• (2) 0.6932
• (3) 6.932
• (4) 0.006932