Chemical Kinetics MCQ

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• The value of the rate constant for the gas phase reaction, 2NO₂ + F₂ → 2NO₂F is 38 dm³ mol^-1 s^-1 at 300K. The order of the reaction is
  ক

  0

  খ

  1

  গ

  2

  ঘ

  3
• The fluorescence life time of a molecule in solution is 10 ns. If the fluorescence quantum yield is 0.1, the rate constant of fluorescence decay is
  ক

  1 × 10⁹ s^-1

  খ

  1 × 10⁸ s^-1

  গ

  1 × 10⁷ s^-1

  ঘ

  9 × 10⁷ s^-1
• In a consecutive first order reaction,<br>(where k₁ and k₂ are the respective rate constants) species B has transient existence. Therefore,
  ক

  k₁ ≈ k₂

  খ

  k₁ = 2k₂

  গ

  k₁ ≫ k₂

  ঘ

  k₁ ≪ k₂
• The specific rate constant of decomposition of a compound is represented by $$\ln k = 5.0 - \frac{{12000}}{T}$$<br>The activation energy of decomposition foe this compound at 300 K is
  ক

  24 kcal/mol

  খ

  12 kcal/mol

  গ

  24 cal/mol

  ঘ

  12 cal/mol
• For the reaction, P + Q + R → S, experimental data for the measured initial rates is given below:<br>
  ক

  <table class="table-style-1"> <tr> <td><strong>Expt.</strong></td> <td><strong>Initial conc. P<br>(M)</strong></td> <td><strong>Initial conc. Q<br>(M)</strong></td> <td><strong>Initial conc. R<br>(M)</strong></td> <td><strong>Initial rate<br>(m/s)</strong></td> </tr> <tr> <td>1</td> <td>0.2</td> <td>0.5</td> <td>0.4</td> <td>8.0 × 10^-5</td> </tr> <tr> <td>2</td> <td>0.4</td> <td>0.5</td> <td>0.4</td> <td>3.2 × 10^-4</td> </tr> <tr> <td>3</td> <td>0.4</td> <td>2.0</td> <td>0.4</td> <td>1.28 × 10^-3</td> </tr> <tr> <td>4</td> <td>0.1</td> <td>0.25</td> <td>1.6</td> <td>4.0 × 10^-5</td> </tr></table>The order of the reaction with respect to P, Q and R respectively, is 2, 2, 1

  খ

  2, 1, 2

  গ

  2, 1, 1

  ঘ

  1, 1, 2
• In a homogeneous catalytic reaction, 1.0 M of a substrate band 1.0 μM of a catalyst yields 1.0 mM of a product in 10 s. The turnover frequency (TOF) of the reaction (S^-1) is
  ক

  10^-2

  খ

  10²

  গ

  10^-3

  ঘ

  10³
• If k_a ≫ k_b, then concentration versus time plot for the reaction is
  ক

  <img src="/images/option-image/engineering-chemistry/chemical-kinetics/1689834831-20-1.png" title="Chemical Kinetics mcq question image" alt="Chemical Kinetics mcq question image">

  খ

  <img src="/images/option-image/engineering-chemistry/chemical-kinetics/1689834841-20-2.png" title="Chemical Kinetics mcq question image" alt="Chemical Kinetics mcq question image">

  গ

  <img src="/images/option-image/engineering-chemistry/chemical-kinetics/1689834851-20-3.png" title="Chemical Kinetics mcq question image" alt="Chemical Kinetics mcq question image">

  ঘ

  <img src="/images/option-image/engineering-chemistry/chemical-kinetics/1689834923-20-4.png" title="Chemical Kinetics mcq question image" alt="Chemical Kinetics mcq question image">
• The reaction, 2NO(g) + O₂(g) → 2NO₂(g) proceeds via the following steps:<br>NO + NO \[\xrightarrow{{{{\text{K}}_{\text{a}}}}}\
  ক

  N₂O₂<br>N₂O₂ \ NO + NO<br>N₂O₂ + O₂ \{{{{\text{k}}_{\text{b}}}}}\

  খ

   NO₂ + NO₂<br>The rate of this reaction is equal to

  গ

  <p><span>A.</span> 2k_b

  ঘ

  </span> (2K_ak_b²)/(K_a + k_b)
• 1 g of ⁹⁰Sr gets converted to 0.953 g after 2 yr. The half-life of ⁹⁰Sr, and the amount of ⁹⁰Sr remaining after 5 yr are
  ক

  1.44 yr and 0.916 g

  খ

  57.6 yr and 0.75 g

  গ

  28.8 yr and 0.887 g

  ঘ

  100 yr and 0.982 g
• Consider an exothermic reaction, $$A\mathop {\mathop \rightleftharpoons \limits_{{k_{ - 1}}} }\limits^{{k_1}} I$$<br>As the temperature increases
  ক

  k₁, k_-1 and k₁/k_-1 increase

  খ

  k₁ increases, k_-1 decreases and k₁/k_-1 increases

  গ

  k₁, k_-1 and k₁/k_-1 decrease

  ঘ

  k₁ and k_-1 decrease and k₁/k_-1 increases
• The half-life time for a reaction at initial concentrations of 0.1 and 0.4 mol^-1 are 200 s and 50 s respectively. The order of the reaction is
  ক

  0

  খ

  1

  গ

  2

  ঘ

  3
• For the reaction, 2X₃ $$ \rightleftharpoons $$ 3X₂, the rate of formation of X₂ is
  ক

  $$3\left( {\frac{{ - d\left}}{{dt}}} \right)$$

  খ

  $$\frac{1}{2}\left( {\frac{{ - d\left}}{{dt}}} \right)$$

  গ

  $$\frac{1}{3}\left( {\frac{{ - d\left}}{{dt}}} \right)$$

  ঘ

  $$\frac{3}{2}\left( {\frac{{ - d\left}}{{dt}}} \right)$$
• For a given first order reaction, the reactant reduces to $${\frac{1}{4}^{{\text{th}}}}$$ its initial value in 10 min. The rate constant of the reaction is
  ক

  0.1386 min^-1

  খ

  0.0693 min^-1

  গ

  0.1386 mol L^-1min^-1

  ঘ

  0.0693 mol L^-1min^-1
• The half-life of a first order reaction varies with temperature according to
  ক

  In t_1/2 ∝ 1/T

  খ

  In t_1/2 ∝ T

  গ

  t_1/2 ∝ 1/T²

  ঘ

  t_1/2 ∝ T²
• Sucrose is converted to a mixture of glucose and fructose in a pseudo first order process under alkaline conditions. The reaction has a half-life of 28.4 min. The time required for the reduction of a 8.0 mM sample of sucrose to 1.0 mM is
  ক

  56.8 min

  খ

  170.4 min

  গ

  85.2 min

  ঘ

  227.2 min
• The rate constant of a reaction is 6 × 10-3 s-1 at 50° and 9 × 10-3 s-1 at 100° C. Calculate the energy of activation of the reaction.
  ক

  6.123 kJ mol-1

  খ

  8.124 kJ mol-1

  গ

  12.357 kJ mol-1

  ঘ

  18.256 kJ mol-1
• What is the value of rate constant k if the value of the activation energy Ea and the frequency factor A are 49 kJ / mol and 9 × 1010 s-1 respectively? (T = 313 K)
  ক

  6 × 102 s-1

  খ

  9 × 102 s-1

  গ

  6 × 10-2 s-1

  ঘ

  3 × 102 s-1
• The activation energy of a reaction is 50 kJ mol-1 and the value of rate constant at 300 K is 2.5×10-5 sec-1. What is the value of the frequency factor, A?
  ক

  4228.53 s-1

  খ

  3829.69 s-1

  গ

  7596.45 s-1

  ঘ

  6565.35 s-1
• What is R in the equation k = Ae-Ea/RT?
  ক

  R = 8.314 J K-1 mol-1

  খ

  R = 3.184 J K-1 mol-1

  গ

  R = 4.318 J K-1 mol-1

  ঘ

  R = 1.438 J K-1 mol-1
• Which of the following represents the Boltzmann factor?
  ক

  e-Ea

  খ

  eEa

  গ

  e-Ea/RT

  ঘ

  eEa/RT
• Which of the following is the correct Arrhenius equation?
  ক

  k = A eEa/RT

  খ

  k = A eEa/T

  গ

  k = A eEa/R

  ঘ

  k = A e-Ea/RT
• What happens to the peak of the curve in the Maxwell-Boltzmann distribution graph if temperature increases?
  ক

  Shifts forward and upward

  খ

  Shifts forward and downward

  গ

  Shifts backward and upward

  ঘ

  Shifts backward and downward
• The rate of reaction increases with a rise in temperature.
  ক

  True

  খ

  False
• Which of the following is the correct expression for the temperature coefficient (n)?
  ক

  n = Rate constant at T + 10°/Rate constant at T°

  খ

  n = Rate constant at T + 20°/Rate constant at T°

  গ

  n = Rate constant at T + 30°/Rate constant at T°

  ঘ

  n = Rate constant at T + 40°/Rate constant at T°
• The rate of a reaction depends on the temperature.
  ক

  True

  খ

  False
• For the reaction C2H5COOC2H5 + H2O → C2H5COOH + C2H5OH, find the concentration of if the rate constant k=0.2 and the rate of the reaction is 0.39 s-1.
  ক

  if the rate constant k=0.2 and the rate of the reaction is 0.39 s-1. ] 2.87 M

  খ

  C2H5COOC2H5

  গ

  C2H5COOC2H5

  ঘ

  C2H5COOC2H5
• Which of the following is not an example of a pseudo first-order reaction?
  ক

  CH3COOC2H5 + NaOH → CH3COOH + H2O

  খ

  CH3COOC2H5 + H2O → CH3COOH + C2H5OH

  গ

  C2H5COOC2H5 + H2O → C2H5COOH + C2H5OH

  ঘ

  C12H22O11 + H2O → glucose + fructose
• Which of the following is not similar between a first order and pseudo first order reaction?
  ক

  The molecularity is one in both the reactions

  খ

  Both follows first order kinetics

  গ

  The unit of rate constant is s-1

  ঘ

  The rate of the reaction depends only on one reactant
• Which of the following is not true for a pseudo first-order reaction?
  ক

  The reaction follows first order kinetics

  খ

  Molecularity of the reaction should be one

  গ

  The reactants such as water are present in excess and are assumed to be constant throughout the reaction

  ঘ

  Unit of the rate constant is s-1
• What is the rate law of hydrolysis of CH3COOC2H5 in aqueous solution? 2 b) R=k c) R=k d) R=kk’
  ক

  R=k 2

  খ

  CH3COOC2H5

  গ

  CH3COOC2H5

  ঘ

  CH3COOC2H5