Half-life and methods to determine order

27 questions on Half-life and methods to determine order from the Chemical Kinetics chapter: 5 NEET level, 11 JEE Main, 11 JEE Advanced. Each one opens with its answer and solution.

• For a first order reaction, if the initial concentration of the reactant is doubled, the half-life NEET level
• For a zero order reaction, doubling the initial concentration of the reactant makes the half-life NEET level
• For a second order reaction of the type 2A -> P, the initial concentration is made three times larger. The half-life becomes NEET level
• A first order reaction has k = 0.0231 min^-1. Using ln 2 = 0.693, its half-life is NEET level
• In an experiment on a reaction of the type A -> P, the concentration of A was increased to three times its value and the initial rate became nine times larger. ... NEET level
• A first order reaction has a half-life of 40 min. The percentage of the reactant remaining after 2 h is JEE Main level
• A zero order reaction has k = 5.0x10^-3 mol L^-1 s^-1 and [A]_0 = 0.60 mol L^-1. Its half-life is JEE Main level
• For a reaction of the type A -> P, the half-life is 80 min when [A]_0 = 0.10 mol L^-1 and 40 min when [A]_0 = 0.20 mol L^-1. The order of the reaction is JEE Main level
• For A + B -> products the following initial rate data were obtained. Experiment 1: [A] = 0.10, [B] = 0.10, initial rate = 2.0x10^-3. Experiment 2: [A] = 0.20, [... JEE Main level
• A reaction 2A -> P is second order with k = 0.0125 L mol^-1 s^-1 (for -d[A]/dt = k[A]^2). Calculate its half-life, in minutes (two decimals), when [A]_0 = 0.20 ... JEE Main level
• The half-life of a first order reaction is 25 min. Using log 2 = 0.3010, calculate the time (in minutes, two decimals) needed for 90% of the reactant to be cons... JEE Main level
• For a reaction A -> products the half-life is 600 s at [A]_0 = 0.10 mol L^-1 and 300 s at [A]_0 = 0.40 mol L^-1. Using t_1/2 propto [A]_0^ 1-n, find the order n... JEE Main level
• A substance decomposes on a metal surface by a zero order reaction. Its concentration falls from 0.80 mol L^-1 to 0.50 mol L^-1 in 30 min. Calculate the half-li... JEE Main level
• Select the correct statement(s) about the dependence of half-life t_1/2 on the initial concentration a for reactions of order n. JEE Main level
• Initial rate data for A + B -> products (concentrations in mol L^-1, rates in mol L^-1 s^-1): Experiment 1: [A] = 0.10, [B] = 0.10, rate = 5.0x10^-4. Experiment... JEE Main level
• A reaction has a half-life of 50 min for [A]_0 = 0.80 mol L^-1 and 25 min for [A]_0 = 0.40 mol L^-1. Select the correct statement(s). JEE Main level
• Initial rates for A + B -> products (concentrations in mol L^-1, rates in mol L^-1 s^-1): (i) [A]=0.10, [B]=0.10, rate =2.50x10^-4; (ii) [A]=0.20, [B]=0.10, rat... JEE Advanced level
• For a reaction of the type A -> products, the concentration of A is 0.80 mol L^-1 at t = 0, 0.40 at t = 50 min and 0.20 at t = 150 min. The order and rate const... JEE Advanced level
• For A -> products a plot of log(rate) against log[A] (rate in mol L^-1 min^-1, [A] in mol L^-1) is a straight line of slope 2.00 and intercept -1.699. Take log ... JEE Advanced level
• A first order reaction and a zero order reaction have the same initial concentration and the same half-life of 60 min. At t = 90 min the ratio [A]_first/[A]_zer... JEE Advanced level
• For A + B -> P with B in large excess, the half-life of A does not depend on [A]_0. It is 10 min when [B]_0 = 0.10 mol L^-1 and 2.5 min when [B]_0 = 0.20 mol L^... JEE Advanced level
• A reaction A -> P has a half-life of 40 min for [A]_0 = 0.50 mol L^-1 and 20 min for [A]_0 = 1.00 mol L^-1. Starting from [A]_0 = 0.25 mol L^-1, calculate the t... JEE Advanced level
• A first order reaction is 40% complete in 20 min. Using log 2 = 0.3010 and log 3 = 0.4771, calculate the time (in minutes, nearest integer) for the reaction to ... JEE Advanced level
• Ammonia decomposes on a hot tungsten surface by a zero order reaction, 2NH3(g) -> N2(g) + 3H2(g), at constant volume and temperature. Starting with pure NH3 at ... JEE Advanced level
• Concentration data for A -> products (in mol L^-1): 0.800 at t = 0, 0.400 at 20 min, 0.200 at 40 min, 0.100 at 60 min. Take ln 2 = 0.693. Select the correct sta... JEE Advanced level
• Three reactions X (zero order), Y (first order) and Z (second order) each start with 1.00 mol L^-1 of reactant and each has a half-life of 10 min at this concen... JEE Advanced level
• The gas-phase decomposition of A shows a half-life of 100 s when the initial pressure is 300 mmHg and again 100 s when it is 150 mmHg. Take log 2 = 0.3010 and l... JEE Advanced level