Chemical Engineering - MCQ Practice Questions

The minor losses in pipe fittings are expressed as K×(V²/2g) where K is the loss coefficient. For a 90° elbow with Re = 50,000, typical K value is:

In a centrifugal pump, the head developed is given by Euler's pump equation. If impeller outlet tangential velocity is 20 m/s and inlet tangential velocity is 4 m/s, calculate theoretical head (g = 9.81 m/s²):

In boundary layer theory on a flat plate, the displacement thickness δ* represents:

For compressible flow through a nozzle, if pressure drops significantly and reaches sonic conditions, the Mach number at that point is:

A hydraulic jump occurs in open channel flow when:

The Moody diagram is used to determine friction factor for pipe flow. It shows that friction factor increases with:

For a horizontal pipe with diameter variation from D₁ to D₂, if pressure difference is ΔP and ignoring losses, the velocity ratio V₁/V₂ is:

Which type of reactor provides the best conversion for a reversible exothermic reaction?

In a CSTR operating at steady state, if residence time is doubled and inlet concentration remains constant, how does conversion change for a first-order reaction?

For parallel reactions A→B and A→C, the selectivity of B over C is defined as:

In a catalytic reaction, which parameter does NOT affect the rate of reaction?

For the reaction 2A → B, if initial concentration of A is 2 mol/L and concentration after 5 minutes is 1 mol/L, calculate rate constant (assuming second-order):

The Damköhler number (Da) in chemical reactor design represents:

In enzyme catalysis, what does the Michaelis-Menten constant (K_m) represent?

For an exothermic reaction in an adiabatic reactor, what happens to the reaction rate as conversion increases?

For autocatalytic reactions, which reactor gives highest conversion at equilibrium?

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?