Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202117 MarchMorning Shift
Exam
JEE Main
Year
2021
Date
17 March
Shift
Morning Shift
Subject
Chemistry
Chapter
Chemical Kinetics

JEE Main 2021 · 17 March · Morning Shift · Chemistry · Chemical Kinetics

For a certain first order reaction 32 % of the reactant is left...

For a certain first order reaction 3232 % of the reactant is left after 570s.570s . The rate constant of this reaction is ×10−3s−1.\times {10}^{- 3}{s}^{- 1} . (Round off to the Nearest Integer).

[Given: log⁡102=0.301,ln⁡10=2.303\log_{10}2 = 0 . 301, \ln 10 = 2 . 303]

Correct answer

0

Step-by-step solution

For 1st{1}^{\text{st}} order reaction,

K=2.303t⋅log[A0][At]=2.303570sec⋅log⁡(10032)K = \dfrac{2 . 303}{t} \cdot log\dfrac{\left[{A}_{0}\right]}{\left[{A}_{t}\right]} = \dfrac{2 . 303}{570sec} \cdot \log \left(\dfrac{100}{32}\right)

=1.999×10−3sec⁡−1≈2×10−3sec⁡−1= 1 . 999 \times {10}^{- 3}\sec^{- 1} \approx 2 \times {10}^{- 3}\sec^{- 1}

Practice Chemical Kinetics on Quantrex Academy →

More from Chemical Kinetics

For a reversible reaction R leftharpoons P , at constant temperature, both the forward… JEE Advanced 2026For a first-order reaction R P at a given temperature, k is the rate constant. For this… JEE Advanced 2026Given below are two statements: R=8.314 J K ^ -1 mol ^ -1 and 1 cal =4.2 J Statement I… JEE Main 2026Decomposition of a hydrocarbon follows the equation k = (5.5 × 10^ 11 \,s^ -1 )\,e^… JEE Main 2026For a reaction A arrow P at T K , the half life (t_ 1/2 ) is plotted as a function of… JEE Main 2026First order gas phase reaction A arrow B + C p_i = initial pressure of gas A, p_t = total… JEE Main 2026If the half life of a first order reaction is 6.93 minutes then the time required for… JEE Main 2026Consider the given graph showing variation of reactant concentration with time. Three… JEE Main 2026 Full Chemical Kinetics list All JEE Main PYQs