Chemical Engineering Gate 2026 Questions with Answer

Ques 40 GATE 2026

The flooding velocity curves for two different structured packings are shown in the figure. The ratio of mass velocities of liquid (G_x) to that of the gas (G_y) is 1.27. The density of the liquid (ρ_x) is 1200 kg m⁻³ and that of the gas (ρ_y) is 1.2 kg m⁻³. For both the packings, the allowable superficial vapor velocity is 60% of flooding velocity (u_0,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).

Ques 41 GATE 2026

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.

Ques 42 GATE 2026

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 (p_A) as a function of axial distance z is shown in the figure. The partial pressure of component B (p_B) approaches zero at z = 0.8 m. At a location z = z₁ the partial pressures of the components A and B are equal. The value of z₁ (in m) is _____ (rounded off to two decimal places).

Ques 43 GATE 2026

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.

Ques 44 GATE 2026

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

Ques 45 GATE 2026

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 c₀ is the concentration of VOC in the feed. The breakthrough time for the bed is 2.1 h. The area under c/c₀ curve between the initial and breakthrough times is 0.1 h. Which one of the following is the fraction of unused bed at breakthrough?

Ques 46 GATE 2026

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 assume constant molal overflow. Which one of the following is the minimum reboiler heat duty (in kW)?

Ques 47 GATE 2026

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 = 0.9x, 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 (H_tOG) is 0.8 m and the number of overall gas transfer units (N_tOG) is given by the integral N_tOG = ∫_y1^y2 dy/(y−y*). Which one of the following is the minimum length of the packing (in m) necessary to achieve the desired scrubbing?

Ques 48 GATE 2026

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

Ques 49 GATE 2026

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).

Ques 50 GATE 2026

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)?

Ques 51 GATE 2026

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(m³): 1×10⁻³, 2×10⁻³; Time(s): 40, 100
The filter area is 0.05 m² and viscosity of filtrate is 10⁻³ Pa s. Which one of the following is the filter medium resistance (in m⁻¹)?

Ques 52 GATE 2026

Which of the following methods for calculating profitability does/do NOT consider the time value of money?