Rates Flashcards
What are successful collisions?
During the collisions, the old bond is broken and two new bonds are made.
What are unsuccessful collisions?
The force of the collision is not enough to break the existing bonds.
What is activation energy?
The minimum energy that a pair of colliding molecules need in order to react.
Why does increasing the surface area of a solid reactant increase the rate?
The rate of the reaction depends on the number of successful collisions per second.
More molecules are exposed for collisions, and so they collide more frequently.
Consequently, there must be more successful collisions per second.
Why does increasing the concentration of a solution increase the rate?
The rate of a reaction depends on the number of successful collisions per second.
By increasing the conc, there are more molecules present in a given volume so there will be more frequent collisions per second.
Consequently, there must be more successful collisions per second.
why does increasing the pressure of a gas increase the rate?
The rate of a reaction depends on the number of successful collisions per second.
By increasing the pressure, the molecules move close together and so there are more molecules present in a given volume so there will be more collisions per second.
Consequently, there must be more successful collisions per second.
Why does increasing the temperature increase the rate?
The rate of a reaction depends on the number of successful collisions per second.
If the temperature is increased the molecules have more kinetic energy so they collide more frequently and more colliding molecules now have energy greater than of equal to the activation energy and can react on collisions
Consequently there will be many more successful collisions per second.
Why does using a catalyst, increase the rate?
The rate of a reaction depends on the number of successful collisions per second.
A catalyst provides an alternative reaction pathway of lower activation energy. Therefore more molecules have energy greater than or equal to the activation energy.
Consequently there will be many more successful collisions per second.
