Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AIIMS 201925 May
Exam
AIIMS
Year
2019
Date
25 May
Subject
Chemistry
Chapter
Chemical Kinetics

AIIMS 2019 · 25 May · Chemistry · Chemical Kinetics

Find out the time required for 2 / 3^ rd completion of a first...

Find out the time required for 2/3rd 2 / 3^{\text{rd }} completion of a first order reaction, if the value of rate constant is 4.3×10−4s−1.4.3 \times 10^{-4} \mathrm{ s}^{-1} .

Options

  1. A0.0025×103 s0.0025 \times 10^3 \mathrm{~s}
  2. B0.25×103 s0.25 \times 10^3 \mathrm{~s}
  3. C0.025×103 s0.025 \times 10^3 \mathrm{~s}
  4. D2.5×103 s2.5 \times 10^3 \mathrm{~s}

Correct answer

D. 2.5×103 s2.5 \times 10^3 \mathrm{~s}

Step-by-step solution

For a first order reaction, k=2.303tlog⁡aa−x∴t=2.3034.3×10−4log⁡aa/3=2.55×103 s\begin{aligned} & k=\frac{2.303}{t} \log \frac{a}{a-x} \\ & \therefore \quad t=\frac{2.303}{4.3 \times 10^{-4}} \log \frac{a}{a / 3}=2.55 \times 10^3 \mathrm{~s}\end{aligned}
Practice Chemical Kinetics on Quantrex Academy →

More from Chemical Kinetics

The combination of NO_2(g) and CO(g) occurs in two steps as follows: What is the rate law… MHT CET Medical 2026The slope of the graph [A]_t against time for zero order reaction is MHT CET Medical 2026For the reaction C_2H_5Br_ (l) arrow C_2H_ 4(g) + HBr , r = K(C_2H_5Br) What is order and… MHT CET Medical 2026The decomposition of N_2O_ 5(g) occurs as: 2\ N_2O_ 5(g) arrow 4\ NO_ 2(g) + O_ 2(g) . If… MHT CET Medical 2026Which of the following statements represents rate of reaction? MHT CET Medical 2026What is the order of reaction for the following? 2H_2O_2(l) arrow 2H_2O(l) + O_2(g) MHT CET Medical 20262A k B is a zero-order reaction, where k=1.0 mol L ^ -1 min ^ -1 . If the initial… NEET 2026Match List I with List II : List I (Order of reaction) List II (Unit of rate constant) A.… NEET 2026 Full Chemical Kinetics list All AIIMS PYQs