from the diagram, when the temperatures of reactants are raised from 20°c to 30°c:\nthe total number of…

from the diagram, when the temperatures of reactants are raised from 20°c to 30°c:\nthe total number of collisions doubles.\nthe number of molecules having eᵣ or greater doubles.\nthe average kinetic energy doubles.\nthe number of molecules doubles.

from the diagram, when the temperatures of reactants are raised from 20°c to 30°c:\nthe total number of collisions doubles.\nthe number of molecules having eᵣ or greater doubles.\nthe average kinetic energy doubles.\nthe number of molecules doubles.

Answer

Explanation:

Step1: Understand reaction - rate concept

Increasing temperature in a reaction system mainly affects the number of molecules with sufficient energy ($E_r$ or greater) to react.

Step2: Analyze each option

  • The total number of collisions does not simply double with a 10 - degree temperature increase. Collision frequency is related to temperature but not in a simple doubling - relationship.
  • When temperature increases from 20°C to 30°C, according to the Arrhenius concept and Maxwell - Boltzmann distribution, the number of molecules having the activation energy ($E_r$) or greater approximately doubles.
  • The average kinetic energy of molecules is proportional to the temperature in Kelvin ($KE=\frac{3}{2}kT$). A 10 - degree increase from 20°C (293 K) to 30°C (303 K) does not double the average kinetic energy.
  • The number of molecules in the system is determined by the amount of substance and is not affected by a small temperature change like this.

Answer:

The number of molecules having $E_r$ or greater doubles.