List of top Chemical Reaction Engineering Questions

Methane combusts with air in a furnace according to the reaction \( \text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O} \). The heat of reaction \( \Delta H_{\text{rxn}} \) is -880 kJ per mol of CH4 and is assumed constant. The furnace is well-insulated, and no side reactions occur. All components behave as ideal gases with a constant molar heat capacity of 44 J mol\(^{-1}\) °C\(^{-1}\). Air is composed of 20 mol% O2 and 80 mol% N2. The air-fuel mixture enters the furnace at 50°C. The methane conversion \( X \) varies with the air-to-methane mole ratio \( r \) as \( X = 1 - 0.1 e^{-2(r-r_s)} \) with \( 0.9 r_s \leq r \leq 1.1 r_s \), where \( r_s \) is the stoichiometric air-to-methane mole ratio. For \( r = 1.05 r_s \), the exit flue gas temperature in °C, rounded off to 1 decimal place, is _____.

Two parallel first-order liquid phase reactions \( A \xrightarrow{k_1} B \) and \( A \xrightarrow{k_2} C \) are carried out in a well-mixed isothermal batch reactor. The initial concentration of A in the reactor is \( 1 \) kmol m\(^{-3}\), while that of B and C is zero. After 2 hours, the concentration of A reduces to half its initial value, and the concentration of B is twice that of C. The rate constants \( k_1 \) and \( k_2 \), in h\(^{-1}\), are, respectively,

The rate of a reaction \( A \rightarrow B \) is \( 0.2 \) mol m\(^{-3}\) s\(^{-1}\) at a particular concentration \( C_{A1} \). The rate constant of the reaction at a given temperature is \( 0.1 \) m\(^3\) mol\(^{-1}\) s\(^{-1}\). If the reactant concentration is increased to \( 10 C_{A1} \) at the same temperature, the reaction rate, in mol m\(^{-3}\) s\(^{-1}\), is

A chemostat with cell recycle is shown in the figure. The feed flow rate and culture volume are \( F = 75 \) L/h and \( V = 200 \) L, respectively. The glucose concentration in the feed \( C_{S0} = 15 \) g/L. Assume Monod kinetics with specific cell growth rate \(\mu_g=\)\( \frac{1}{C_c} \frac{dC_c}{dt} = \frac{\mu_m C_S}{K_s + C_S} \),, where \( \mu_m = 0.25 \) h\(^{-1}\) and \( K_s = 1 \) g/L. Assume  maintenance, and death rates to be zero, input feed to be sterile (\( C_{S0} = 0 \)), and steady-state operation. The glucose concentration in the recycle stream, \( C_{S1} \), in g/L, rounded off to 1 decimal place, is ____.

For purchasing a batch reactor, three alternatives P, Q and R have emerged, as summarized in the table. For a compound interest rate of 10% per annum, choose the correct option that arranges the alternatives, in order, from the least expensive to the most expensive

A first-order liquid phase reaction \( A \rightarrow B \) is conducted in two isothermal plug flow reactors (PFRs) of volume 1 m\(^3\) each, connected in series. The feed flow rate and concentration of A to the first reactor are 10 m\(^3\) h\(^{-1}\) and 1 kmol m\(^{-3}\), respectively. At steady-state, the concentration of A at the exit of the second reactor is 0.2 kmol m\(^{-3}\). If the two PFRs are replaced by two equal-volume continuously stirred tank reactors (CSTRs) to achieve the same overall steady-state conversion, the volume of each CSTR, in m\(^3\), is:

The residence time distribution, \( E \), for a non-ideal flow reactor is provided in the figure. A first-order liquid phase reaction with a rate constant of 0.2 min\(^{-1}\) is conducted in the reactor. If the inlet reactant concentration is 2 mol L\(^{-1}\), the reactant concentration (in mol L\(^{-1}\)) in the exit stream is

A first-order heterogeneous reaction \( A \rightarrow B \) is conducted using a porous spherical catalyst under isothermal conditions, where intraphase diffusion governs the reaction rate. At a bulk A concentration of 0.3 mol L\(^{-1}\), the observed reaction rate in a 3 mm diameter catalyst particle is 0.2 mol s\(^{-1}\) L\(^{-1}\) catalyst volume. At a bulk A concentration of 0.1 mol L\(^{-1}\), the observed reaction rate in a 6 mm diameter catalyst particle, in mol s\(^{-1}\) L\(^{-1}\) catalyst volume, is:

Consider the reaction \(N_2(g) + 3H_2(g)\) \(\rightleftharpoons\)\(2NH_3(g)\) in a continuous flow reactor under steady-state conditions. The component flow rates at the reactor inlet are \( F^0_{{N2}} = 100 \) mol s\(^{-1}\), \( F^0_{{H2}} = 300 \) mol s\(^{-1}\), and \( F^0_{\text{inert}} = 1 \) mol s\(^{-1}\). If the fractional conversion of \( {H2} \) is 0.60, the outlet flow rate of \( {N2} \), in mol s\(^{-1}\), rounded off to the nearest integer, is ___

For the electrolytic cell in a chlor-alkali plant, which of the following statements is/are correct?

The ratio of the activation energy of a chemical reaction to the universal gas constant is 1000 K. The temperature-dependence of the reaction rate constant follows the collision theory. The ratio of the rate constant at 600 K to that at 400 K is

In a 400 KV Network, 360 KV is recorded at a 400KV Bus. The reactive power absorbed by stunt reactor rated for 50M VAR. 400KV connected at a BUS is

Choose correct option (Chlor-Alkoli Industry)