Chemical Engineering - MCQ Practice Questions

In a semi-batch reactor for an exothermic consecutive reaction A→B→C, why is controlled addition of A preferred over charging all reactant initially?

For a reaction with order n = 1.5 at initial concentration C₀ = 4 mol/L, if the rate constant is 0.1 (L/mol)⁰·⁵/min, what is the half-life?

Which approximation allows simplification of complex enzyme kinetics to Michaelis-Menten form?

For gas-phase reactions in a packed bed reactor, the Peclet number (Pe) indicates:

In the context of green chemistry and reaction engineering, which reactor configuration minimizes waste generation for a fast, highly exothermic reaction?

For a non-elementary bimolecular reaction where experimental data shows apparent order n = 1.5 with respect to concentration [A], which mechanism is most probable?

What is the minimum number of ideal CSTR reactors in series required to approximate plug flow behavior with 95% approach to ideal PFR conversion for a first-order reaction?

For a gas-phase reaction in a fluidized bed reactor, the overall reaction rate is limited by mass transfer from bulk to catalyst surface. Which step shows zero-order kinetics behavior?

In cascade impaction for studying particle-phase reaction kinetics in reactors, which aerodynamic diameter range represents particles most suitable for chemical reaction on catalyst surfaces?

Which reactor configuration minimizes backmixing while maintaining high mass transfer rates for liquid-liquid reactions between immiscible phases?

For a second-order reaction in a PFR, increasing the inlet concentration while maintaining constant volumetric flow rate will result in:

The Weisz-Prater criterion is used to determine:

For parallel reactions where A → B (desired) with rate constant k₁ and A → C (undesired) with rate constant k₂, the selectivity towards B is maximized by:

In the design of a CSTR for a reaction with Arrhenius parameters: Ea = 50 kJ/mol, A = 10⁵ s⁻¹, what is the approximate k at 50°C?

For a polymerization reaction in a batch reactor, the polydispersity index (PDI) and average molecular weight depend on:

In consecutive reactions A → B → C (both first-order), maximum concentration of intermediate B occurs at which time?

Thiele modulus (φ) represents the ratio of which two parameters in heterogeneous catalysis?

In a recycle reactor with recycle ratio R, what is the volume reduction factor compared to PFR for equivalent conversion?

For homogeneous gas-phase reaction in batch reactor, if pressure increases at constant volume, what happens to reaction rate for 2A → Products?

The Maxwell relation that can be derived from Gibbs free energy is: