Parallel, consecutive and reversible reactions, catalysis

28 questions on Parallel, consecutive and reversible reactions, catalysis from the Chemical Kinetics chapter: 6 NEET level, 11 JEE Main, 11 JEE Advanced. Each one opens with its answer and solution.

• For A <=> B the forward activation energy is 90 kJ mol^-1 and Delta H = +30 kJ mol^-1. A catalyst lowers the forward activation energy to 70 kJ mol^-1. The acti... JEE Main level
• A undergoes two parallel first-order reactions with k_1 = 4.0x10^-3 s^-1 and k_2 = 3.0x10^-3 s^-1. Using ln 2 = 0.693, find the half-life of A in seconds (neare... JEE Main level
• A decomposes by two parallel first-order paths with activation energies E_1 = 50.0 and E_2 = 90.0 kJ mol^-1. At the temperature of interest the products from th... JEE Advanced level
• A reaction has an uncatalysed path (E_a = 100.0 kJ mol^-1). Adding a catalyst opens a second, parallel path with E_a = 90.0 kJ mol^-1, and the uncatalysed path ... JEE Advanced level
• Two parallel first-order reactions of A, giving B and C, have the same pre-exponential factor. Their activation energies are 60.0 and 65.0 kJ mol^-1 respectivel... JEE Main level
• A (initial concentration 0.800 M) undergoes parallel first-order reactions A -> B (k_1 = 0.030 min^-1) and A -> C (k_2 = 0.010 min^-1). After t = 34.65 min, fin... JEE Main level
• For the endothermic first-order reaction A <=> B, E_a,f = 80 and Delta H = +30 kJ mol^-1. A catalyst lowers E_a,f to 60 kJ mol^-1 at fixed pre-exponential facto... JEE Advanced level
• In an autocatalytic reaction, where a product speeds up the reaction, the plot of reactant concentration against time typically shows JEE Main level
• Which statements about a catalyst in a reversible reaction are correct? JEE Main level
• A decomposes by two parallel first-order paths, A -> B (k_1 = 3.0x10^-3 s^-1) and A -> C (k_2 = 2.0x10^-3 s^-1). The overall rate constant for the disappearance... NEET level
• A catalyst increases the rate of a reaction because it NEET level
• Which of the following is an example of homogeneous catalysis? NEET level
• A forms B (E_1 = 70.0 kJ mol^-1) and C (E_2 = 50.0 kJ mol^-1) by parallel first-order paths with equal pre-exponential factors. Select the correct statement(s). JEE Advanced level
• For A ->[k_1] B ->[k_2] C with k_1 = 0.10 min^-1, k_2 = 0.50 min^-1 and only A present initially, select the correct statement(s). Use ln 5 = 1.609. JEE Advanced level
• For A ->[k_1] B ->[k_2] C (first order, k_1 = 0.020 min^-1, k_2 = 0.100 min^-1, pure A at t=0), the ratio [B]/[A] at long times (transient equilibrium) approach... JEE Advanced level
• For the consecutive first-order reactions A -> B -> C starting with pure A, the concentration of the intermediate B NEET level
• For a reversible reaction, a catalyst NEET level
• For A <=> B with first-order rate constants k_f = 2.0x10^-2 s^-1 and k_b = 5.0x10^-3 s^-1, the equilibrium constant is NEET level
• For A <=> B (first order both ways, k_f = 0.020 min^-1, k_b = 0.005 min^-1) starting with [A]_0 = 1.00 M and no B, find the time (in min) at which [B] = 0.400 M... JEE Advanced level
• A decomposes by two parallel first-order paths giving B and C in the molar ratio 3:1. The half-life of A is 20.0 min. Using ln 2 = 0.693, the rate constant of t... JEE Advanced level
• A forms B (activation energy E_1) and C (activation energy E_2) by parallel first-order paths, with E_1 - E_2 = 20.0 kJ mol^-1 and a temperature-independent rat... JEE Advanced level
• For A ->[k_1] B ->[k_2] C with k_1 = 5.0x10^-2 s^-1 and k_2 = 2.0x10^-4 s^-1, the rate at which C appears after the initial period is governed mainly by JEE Main level
• An enzyme obeys E + S <=>[k_1][k_-1] ES ->[k_2] E + P with k_1 = 1.0x10^6 M^-1 s^-1, k_-1 = 5.0x10^3 s^-1, k_2 = 5.0x10^3 s^-1. Applying the steady-state approx... JEE Advanced level
• For A ->[k_1] B ->[k_2] C (first order, k_1 = 0.20 min^-1, k_2 = 0.05 min^-1, only A present initially), the time at which [B] is maximum is t_max = ln(k_1/k_2)... JEE Main level
• For A ->[k_1] B ->[k_2] C with k_1 = 0.30 min^-1, k_2 = 0.10 min^-1 and [A]_0 = 0.600 M (no B or C initially), find the maximum concentration of B in M (two dec... JEE Advanced level
• A undergoes parallel first-order reactions A -> B (k_1 = 3.0x10^-2 min^-1) and A -> C (k_2 = 1.0x10^-2 min^-1). Use ln 2 = 0.693. Select the correct statement(s... JEE Main level
• The first-order reversible reaction A <=> B has k_f = 0.030 min^-1 and k_b = 0.020 min^-1. The deviation ([A] - [A]_eq) decays exponentially with rate constant ... JEE Main level
• A catalyst lowers the activation energy of a reaction from 80.0 to 60.0 kJ mol^-1 without changing the pre-exponential factor. At 300 K (R = 8.314 J mol^-1 K^-1... JEE Main level