If the half-life (\(t_{1/2}\)) for a first order reaction is 1 minute, then the time required for 99.9% completion of the reaction is closest to :
Chemical Kinetics
Every question from past board papers on Chemical Kinetics, newest paper first. Open any question for its full worked answer.
NEET UG 2025 question paper (official, booklet 45)
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If the rate constant of a reaction is 0.03 \(\mathrm{s^{-1}}\), how much time does it take for 7.2 mol \(\mathrm{L^{-1}}\) concentration of the reactant to get reduced to 0.9 mol \(\mathrm{L^{-1}}\)?
(Given: log 2 = 0.301)
NEET UG 2024 question paper (official, booklet S6)
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Activation energy of any chemical reaction can be calculated if one knows the value of
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Which plot of ln k vs \(\frac{1}{T}\) is consistent with Arrhenius equation?
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The rate of a reaction quadruples when temperature changes from 27\(^\circ\)C to 57\(^\circ\)C. Calculate the energy of activation.
Given R = 8.314 J \(K^{-1}\) \(mol^{-1}\), log 4 = 0.6021
NEET UG 2023 question paper (official, booklet G6)
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Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :
Assertion A : A reaction can have zero activation energy.
Reasons R : The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy.
In the light of the above statements, choose the correct answer from the options given below :
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For a certain reaction, the rate = k[A]\(^2\)[B], when the initial concentration of A is tripled keeping concentration of B constant, the initial rate would
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Which one is an example of heterogenous catalysis?
NEET UG 2022 question paper (official, booklet R6)
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The given graph is a representation of kinetics of a reaction.
[Graph: y versus x at constant temperature T]
The \(y\) and \(x\) axes for zero and first order reactions, respectively are
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For a first order reaction A \(\to\) Products, initial concentration of A is 0.1 M, which becomes 0.001 M after 5 minutes. Rate constant for the reaction in \(min^{-1}\) is
NEET UG 2021 question paper (official, booklet M4)
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For a reaction A\(\rightarrow\)B, enthalpy of reaction is \(-4.2\) kJ mol\(^{-1}\) and enthalpy of activation is 9.6 kJ mol\(^{-1}\). The correct potential energy profile for the reaction is shown in option.
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The slope of Arrhenius Plot (\(\ln k\) v/s \(\frac{1}{T}\)) of first order reaction is \(-5\times10^3\) K. The value of \(E_a\) of the reaction is. Choose the correct option for your answer.
[Given R=8.314 J K\(^{-1}\)mol\(^{-1}\)]
NEET UG 2020 question paper (official, booklet E1)
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An increase in the concentration of the reactants of a reaction leads to change in :
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The rate constant for a first order reaction is \(4.606\times10^{-3}\) s\(^{-1}\). The time required to reduce 2.0 g of the reactant to 0.2 g is :
NEET UG 2019 question paper (official, booklet P1)
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If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by :
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For the chemical reaction
\(N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)\)
the correct option is :
NEET UG 2018 question paper (official, booklet EE)
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The correct difference between first- and second-order reactions is that
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When initial concentration of the reactant is doubled, the half-life period of a zero order reaction
NEET UG 2017 question paper (official, booklet B)
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Mechanism of a hypothetical reaction \(X_2 + Y_2 \rightarrow 2XY\) is given below :
(i) \(X_2 \rightarrow X + X\) (fast)
(ii) \(X + Y_2 \rightleftharpoons XY + Y\) (slow)
(iii) \(X + Y \rightarrow XY\) (fast)
The overall order of the reaction will be :
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A first order reaction has a specific reaction rate of \(10^{-2}\ sec^{-1}\). How much time will it take for 20 g of the reactant to reduce to 5 g ?
NEET UG 2016 Phase 1 question paper (official, booklet A)
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The rate of a first-order reaction is \(0.04\ mol\ l^{-1}\ s^{-1}\) at 10 seconds and \(0.03\ mol\ l^{-1}\ s^{-1}\) at 20 seconds after initiation of the reaction. The half-life period of the reaction is :
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The addition of a catalyst during a chemical reaction alters which of the following quantities ?
NEET UG 2016 Phase 2 question paper (official, booklet ZZ)
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The decomposition of phosphine [obscured] on tungsten at low pressure is a [obscured] reaction. It is because the