Answer:
The significance of "Er" in the diagram is :
B.) Threshold energy for reaction
Explanation:
Threshold energy : It is total amount of energy required by the reactant molecule to reach the transition state .
Activation energy : It is the excess energy absorbed by the molecules to reach the transition state.
Activation Energy = Threshold Energy - Average Kinetic Energy
This means Activation energy decreases on increasing kinetic energy
On increasing Temperature average kinetic energy of the molecule increases which reduces the activation energy and the reaction occur faster in that case.
Catalyst also reduces the Activation energy.
Er = Threshshold energy for reaction at 30 degree
Ea = Activation Energy
The given figure shows that the threshold energy decreases on increasing the temperature
Only the molecule having energy greater than Er can react to form product
