Chemical Reaction Engineering MCQs 2026

Elementary rate law r = k C_A^n implies

1. Aequilibrium constant✓
2. Bextent of reaction only✓
3. Cheat transfer coefficient✓
4. Dreaction order n with respect to A✓

Arrhenius equation k = A exp(−E/RT) shows rate constant increases with

1. Apressure only always✓
2. Bcatalyst pore length only✓
3. Ctemperature✓
4. Dreactor diameter only✓

CSTR characteristic is

1. Aplug flow with no mixing✓
2. Bno volume holdup✓
3. Conly solid catalyst fixed bed without fluid✓
4. Dwell-mixed contents with uniform composition✓

PFR model assumes

1. Acomplete backmixing✓
2. Bzero flow✓
3. Cfluid elements move in series without mixing axially✓
4. Donly batch operation✓

Space time τ in PFR is

1. AF/V always called residence without volume✓
2. Bonly catalyst weight✓
3. Conly heat duty✓
4. DV/F_total for volumetric basis✓

Thiele modulus relates

1. Aonly external film only✓
2. Bonly pump head✓
3. Conly distillation reflux✓
4. Dreaction rate in pellet to diffusion rate inside pellet✓

Damköhler number compares

1. Areaction rate to transport rate✓
2. Bheat to work✓
3. Cpressure to gravity✓
4. Dmolecular weight to density only✓

Half-life for first-order reaction t_1/2 equals

1. A1/k✓
2. Bk/2✓
3. C0.693/k✓
4. D2/k✓

Mixed flow reactor exit conversion for first-order liquid reaction is

1. AX = kτ/(1+kτ)✓
2. BX = 1 − exp(−kτ) for PFR✓
3. CX = kτ always linear✓
4. DX = 0 always✓

Langmuir-Hinshelwood mechanism applies to

1. Aonly gas-phase chain reactions✓
2. Bonly enzyme in solution without surface✓
3. Conly distillation trays✓
4. Dsurface reaction on catalyst with adsorption steps✓