Chemical Engineering GATE 2021 Questions with Answer

Ques 1 Chemical Engineering Thermodynamics

The heat of combustion of methane, carbon monoxide and hydrogen are P, Q and R respectively. For the reaction below, CH₄+H₂O⟶CO+3H₂ the heat of reaction is given by

Ques 2 Chemical Engineering Thermodynamics

The van der Waals equation of state is given by P_r= (8T_r)/(3v_r-1) - 3/v_r² where P_r T_r and v_r represent reduced pressure, reduced temperature and reduced molar volume, respectively. The compressibility factor at critical point (Z_c) is 3/8.
If v_r=3 and T_r=4/3, then the compressibility factor based on the van der Waals equation of state is _______ (round off to 2 decimal places).

Ques 3 Chemical Engineering Thermodynamics

The molar heat capacity at constant pressure C_p (in J mol^-1K^-1) for n-pentane as a function of temperature (T in K) is given by C_p/R=2.46+45.4×10^-3T-14.1×10^-6T². Take R=8.314 J mol^-1K^-1.
At 1000 K, the rate of change of molar entropy of n-pentane with respect to temperature at constant pressure is _______ J mol^-1K^-2 (round off to 2 decimal places).

Ques 4 Chemical Engineering Thermodynamics

The combustion of carbon monoxide is carried out in a closed, rigid and insulated vessel. 1 mol of CO, 0.5 mol of O₂ and 2 mol of N₂ are taken initially at 1 bar and 298 K, and the combustion is carried out to completion.
The standard molar internal energy change of reaction (Δu_R°) for the combustion of carbon monoxide at 298 K=-282 kJ mol^-1. At constant pressure, the molar heat capacities of N₂ and CO₂ are 33.314 J mol^-1K^-1 and 58.314 J mol^-1K^-1, respectively. Assume the heat capacities to be independent of temperature, and the gases are ideal. Take R=8.314 J mol^-1K^-1.
The final pressure in the vessel at the completion of the reaction is _______ bar (round off to 1 decimal place).

Ques 5 Chemical Engineering Thermodynamics

A gaseous mixture at 1 bar and 300 K consists of 20 mol % CO₂ and 80 mol% inert gas.
Assume the gases to be ideal. Take R=8.314 J mol^-1K^-1.
The magnitude of minimum work required to separate 100 mol of this mixture at 1 bar and 300 K into pure CO₂ and inert gas at the same temperature and pressure is _______ kJ (round off to nearest integer).

Ques 6 Chemical Engineering Thermodynamics

A binary liquid mixture consists of two species 1 and 2. Let γ and x represent the activity coefficient and the mole fraction of the species, respectively. Using a molar excess Gibbs free energy model, In γ₁ vs. x₁ and In γ₂ vs. x₁ are plotted. A tangent drawn to the In γ₁ vs. x₁ curve at a mole fraction of x₁=0.2 has a slope =-1.728.
The slope of the tangent drawn to the In γ₂ vs. x₁ curve at the same mole fraction is _______ (correct to 3 decimal places).

Ques 7 Chemical Reaction Engineering

Ethylene C₂H₄ adsorbs on the vacant active sites V of a transition metal catalyst according to the following mechanism.

Ques 8 Chemical Reaction Engineering

The following homogeneous liquid phase reactions are at equilibrium.

Ques 9 Chemical Reaction Engineering

Match the reaction in Group - 1 with the reaction type in Group - 2.
Group - 1
P Methylcyclohexane ⟶ Toluene + 3H₂
Q Ethylcyclopentane ⟶ Methylcyclohexane
R n-Octane ⟶ Ethylbenzene + 4H₂
S n-Octane ⟶ n-Pentane + Propylene
Group - 2
I Dehydrocyclization
II Cracking
III Dehydrogenation
IV Isomerization
The correct combination is:

Ques 10 Chemical Reaction Engineering

Formaldehyde is produced by the oxidation of methane in a reactor. The following two parallel reactions occur.
CH₄+O₂⟶HCHO+H₂O
CH₄+2O₂⟶CO₂+2H₂O
Methane and oxygen are fed to the reactor. The product gases leaving the reactor include methane, oxygen, formaldehyde, carbon dioxide and water vapor.
60 mol s^-1 of methane enters the reactor. The molar flowrate (in mol s^-1) of CH₄, O₂ and CO₂ leaving the reactor are 26, 2 and 4, respectively. The molar flowrate of oxygen entering the reactor is _______ mol s^-1.

Ques 11 Chemical Reaction Engineering

The following isothermal autocatalytic reaction, A+B⟶2B (-r_A)=0.1C_AC_B(mol L^-1s^-1) is carried out in an ideal continuous stirred tank reactor (CSTR) operating at steady state. Pure A at 1 mol L^-1 is fed, and 90% of A is converted in the CSTR. The space time of the CSTR is _______ seconds.

Ques 12 Chemical Reaction Engineering

Reactant A decomposes to products B and C in the presence of an enzyme in a well-stirred batch reactor. The kinetic rate expression is given by -r_A=(0.01C_A)/(0.05+C_A)(mol L^-1min^-1).
If the initial concentration of A is 0.02 mol L^-1, the time taken to achieve 50% conversion of A is _______ min (round off to 2 decimal places).

Ques 13 Chemical Reaction Engineering

The following homogeneous, irreversible reaction involving ideal gases, A⟶B+C (-r_A)=0.5C_A (mol L^-1 s^-1) is carried out in a steady state ideal plug flow reactor (PFR) operating at isothermal and isobaric conditions. The feed stream consists of pure A, entering at 2m s^-1. In order to achieve 50% conversion of A, the required length of the PFR is _______ meter (round off to 2 decimal places).