Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Advanced 2008Paper 1
Exam
JEE Advanced
Year
2008
Paper
Paper 1
Subject
Chemistry
Chapter
Chemical Kinetics

JEE Advanced 2008 · Paper 1 · Chemistry · Chemical Kinetics

Under the same reaction conditions, initial concentration of 1.386...

Under the same reaction conditions, initial concentration of 1.386 moldm−31.386 \mathrm{~mol} \mathrm{dm}^{-3} of a substance becomes half in 40 s and 20 s through first-order and zero-order kinetics, respectively. Ratio (k1k0)\left(\frac{k_1}{k_0}\right) of the rate constants for first order \left(k_1\right)andzeroand zero\operatorname{order}\left(k_0\right) of the reaction is

Options

  1. A0.5 mol−1dm30.5 \mathrm{~mol}^{-1} \mathrm{dm}^3
  2. B1.0 moldm31.0 \mathrm{~mol} \mathrm{dm}^3
  3. C1.5 moldm31.5 \mathrm{~mol} \mathrm{dm}^3
  4. D2.0 mol−1dm32.0 \mathrm{~mol}^{-1} \mathrm{dm}^3

Correct answer

A. 0.5 mol−1dm30.5 \mathrm{~mol}^{-1} \mathrm{dm}^3

Step-by-step solution

First order kinetics, k1=0.693t1/2=0.69340 s−1k_1=\frac{0.693}{t_{1/2}}=\frac{0.693}{40} \mathrm{~s}^{-1} Zero order kinetics, k1=C02t1/2=1.3862×20k_1=\frac{C_0}{2 t_{1/2}}=\frac{1.386}{2 \times 20} Hence, k1k0=0.6931.386=0.5\frac{k_1}{k_0}=\frac{0.693}{1.386}=0.5
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 Advanced PYQs