Asked in Premeth Test 2 — Reaction KineticsModerate

With the increase of 10°C temperature, the rate of reaction doubles. This increase in rate of reaction is due to:

Correct answer: D. Increase in number of effective collisions

  • A. Decrease in activation energy of reaction
  • B. Decrease in the number of collisions between molecules of reactants
  • C. Increase in activation energy of molecules of reactants
  • D. Increase in number of effective collisions

Explanation

As temperature increases, the kinetic energy of molecules also increases. This heightened energy leads to more frequent and more energetic collisions among reactant molecules. The rate of reaction doubles with a 10°C temperature increase because the number of effective collisions-those with sufficient energy to overcome the activation energy barrier-increases. This does not change the activation energy itself but allows more molecules to have the energy needed to react.The incorrect options misunderstand the concept: activation energy does not change with temperature, and the number of collisions increases, not decreases, with rising temperature.

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About Reaction Kinetics

Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.

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