Q46.For conversion of compound A →B, the rate constant of the reaction was found to be 4. 6 × 10−5 Lmol −1 s−1 . The order of the reaction is _____ .
What This Question Tests
This question tests the fundamental knowledge of how to determine the order of a chemical reaction solely from the units of its rate constant.
Concepts Tested
Formulas Used
Unit of rate constant k = (mol/L)^(1-n) s^(-1)
📚 NCERT Sections This Tests
3.10 — In A Reaction Between A And B, The Initial Rate Of Reaction (R0) Was Measured
Chemistry Class 11 · Chapter 3
3.10 In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below: A/ mol L–1 0.20 0.20 0.40 B/ mol L–1 0.30 0.10 0.05 r0/mol L–1s–1 5.07 × 10–5 5.07 × 10–5 1.43 × 10–4 What is the order of the reaction with respect to A and B? 3.11 The following results have been obtained during the kinetic studies of the reaction: 2A + B ® C + D Experiment [A]/mol L–1 [B]/mol L–1 Initial rate of formation of D/mol L–1 min–1 I 0.1 0.1 6.0 × 10–3 II 0.3 0.2 7.2 × 10–2 III 0.3 0.4 2.88 × 10–1 IV 0.4 0.1 2.40 × 10–2 Determine the rate law and the rate constant for the reaction. 3.12 The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table: Experiment [A]/ mol L–1 [B]/ mol L–1 Initial rate/ mol L–1 min–1 I 0.1 0.1 2.0 × 10–2 II – 0.2 4.0 × 10–2 III 0.4 0.4 – IV – 0.2 2.0 × 10–2 3.13 Calculate the half-life of a first order reaction from their rate constants given below: (i) 200 s–1 (ii) 2 min–1 (iii) 4 years–1 3.14 The half-life for radioactive decay of 14C is 5730 years. An archaeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample. 3.15 The experimental data for decomposition of N2O5 [2N2O5 ® 4NO2 + O2] in gas phase at 318K are given below: t/s 0 400 800 1200 1600 2000 2400 2800 3200 102 × [N2O5]/ 1.63 1.36 1.14 0.93 0.78 0.64 0.53 0.43 0.35 mol L–1 (i) Plot [N2O5] against t. (ii) Find the half-life period for the reaction. (iii) Draw a graph between log[N2O5] and t. (iv) What is the rate law ? Chemistry 86 Reprint 2025-26 (v) Calculate the rate constant. (vi) Calculate the half-life period from k and compare it with (ii).
3.23 — The Rate Constant For The Decomposition Of Hydrocarbons Is 2.418 × 10–5S–1
Chemistry Class 11 · Chapter 3
3.23 The rate constant for the decomposition of hydrocarbons is 2.418 × 10–5s–1 at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.
3.24 — Consider A Certain Reaction A ® Products With K = 2.0 × 10 –2S–1. Calculate
Chemistry Class 11 · Chapter 3
3.24 Consider a certain reaction A ® Products with k = 2.0 × 10 –2s–1. Calculate the concentration of A remaining after 100 s if the initial concentration of A is 1.0 mol L–1.
📋 Question Details
- Chapter
- Chemical Kinetics
- Topic
- Order of Reaction
- Year
- 2023
- Shift
- 29 Jan Shift 2
- Q Number
- Q46
- Type
- Numerical
- NCERT Ref
- Class 12 Chemistry Ch 4: Chemical Kinetics
More from this Chapter
Q93.Consider an endothermic reaction, X ⟶Y with the activation energies Eb and Ef for the backward and forward reactions, respectively. In general (1) Eb < Ef (2) Eb > Ef (3) Eb = Ef (4) There is no definite relation between Eb and Ef
Q90.Rate of a reaction can be expressed by Arrhenius equation as: k = Ae−E/RT In this equation, E represents (1) the energy above which all the colliding (2) the energy below which colliding molecules will molecules will react not react (3) the total energy of the reacting molecules at a (4) the fraction of molecules with energy greater temperature, T than the activation energy of the reaction
Q91.The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr : NO(g) + Br2( g) ⇌NOBr2( g) NOBr2( g) + NO(g) ⟶2NOBr(g) If the second step is the rate determining step, the order of the reaction with respect to NO(g) is (1) 1 (2) 0 (3) 3 (4) 2
Q68.The energies of activation for forward and reverse reactions for A2 + B2 ⇌2AB are 180 kJ mol−1 and 200 kJ mol−1 respectively. The presence of catalyst lowers the activation energy of both (forward and reverse) reactions by 100 kJ mol−1 . The enthalpy change of the reaction (A2 + B2 ⟶2AB) in the presence of catalyst will be (in kJ mol−1 ) (1) 300 (2) 120 (3) 280 (4) 20