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Chemical Kinetics — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryChemical Kinetics5 Marks
Question
Match the statements given in Column I and Column II.
 
Column I
 
Column II
(i)
Catalyst alters the rate of reaction.
(a)
Cannot be fraction or zero.
(ii)
Molecularity
(b)
Proper orientation is not there always.
(iii)
Second half life of first order reaction
(c)
By lowering the activation energy.
(iv)
$\text{e}^{\frac{-\text{Ea}}{\text{RT}}}$
(d)
Is same as the first.
(v)
Energetically favourable reactions are sometimes slow.
(e)
Total probability is one.
(vi)
Area under the Maxwell Boltzman curve is constant.
(f)
Refers to the fraction of molecules with energy equal to or greater than activation energy.
✓

Answer

 
Column I
 
Column II
(i)
Catalyst alters the rate of reaction.
(c)
By lowering the activation energy.
(ii)
Molecularity
(a)
Cannot be fraction or zero.
(iii)
Second half life of first order reaction
(d)
Is same as the first.
(iv)
$\text{e}^{\frac{-\text{Ea}}{\text{RT}}}$
(f)
Refers to the fraction of molecules with energy equal to or greater than activation energy.
(v)
Energetically favourable reactions are sometimes slow.
(b)
Proper orientation is not there always.
(vi)
Area under the Maxwell Boltzman curve is constant.
(e)
Total probability is one.

Explanation:

  1. Catalyst alters the rate of reaction by lowering activation energy.
  2. Molecularity cannot be fraction or zero. If molecularity is zero, reaction is not possible.
  3. Second half-life of first order reaction is same as first because half-life time is temperature independent.
  4.  $\text{e}^{\frac{-\text{Ea}}{\text{RT}}}$ refers to the fraction of molecules with kinetic energy equal to greater than activation energy.
  5. Energetically favourble reactions are sometimes slow due to improper orientation of molecule cause some ineffective collision of molecules.
  6. Area under the Maxwell-Boltzmann curve is constant because total probability of molecule taking part in a chemical reaction is equal to one.

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