Chemical Engineering - MCQ Practice Questions

In a batch reactor operating at constant volume, the rate of reaction for a first-order reaction A→B is -rA = kCA. If the initial concentration is 2 mol/L and k = 0.1 min⁻¹, what will be the concentration after 10 minutes?

What is the primary advantage of a plug flow reactor (PFR) over a continuous stirred-tank reactor (CSTR) for reactions with high activation energy?

In the context of reaction kinetics, which statement best describes the rate-determining step (RDS) in a multi-step reaction mechanism?

For a second-order reaction A+B→C with equal initial concentrations of 1 mol/L, if the rate constant is 0.5 L/(mol·min), what is the time required for 50% conversion?

In a CSTR operating at steady state, the space time (τ) for a first-order reaction is 5 minutes. What is the conversion if k = 0.2 min⁻¹?

Which of the following reactor types is most suitable for producing fine chemicals where precise temperature control is critical?

In the Arrhenius equation k = A×e^(-Ea/RT), if the activation energy is 80 kJ/mol and temperature increases from 300K to 310K, what is the approximate ratio of rate constants k2/k1?

What does the selectivity parameter in a competing reaction system measure?

In a reversible elementary reaction A ⇌ B with forward rate constant kf = 0.1 s⁻¹ and reverse rate constant kr = 0.02 s⁻¹, what is the equilibrium constant K?

Which catalyst property is most important for industrial applications requiring high selectivity in parallel reactions?

For an exothermic reaction, operating a CSTR at higher conversion requires:

In desorption-limited catalytic reactions, which step determines the overall reaction rate?

What is the significance of the Thiele modulus (φ) in heterogeneous catalysis?

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?

In industrial polymerization reactions, what is the primary role of chain termination reactions?

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 reaction A + B → C where both reactants are supplied in stoichiometric ratio, if reaction order with respect to A is 1 and B is 1, and initial concentrations are each 2 mol/L, the integrated rate law shows conversion X varies as: