Rate of reaction and collision theory

Collision Theory- For a reaction to occur, the reactant particles must (3)

- collide with each other
- collide with sufficient energy to break the bonds within the reactants
- collide with the correct orientation to break the bonds within the reactants and to allow the formation of new products

How can you measure rate of reaction? (2)

- Using volume of gas produced
- Using mass loss

How to use volume of gas to measure rate of reaction?

- Collecting Gas with a gas syringe and recording volume.

How to use mass loss to measure rate of reaction?

Measure decrease in mass over time.

What are the two ways of altering the rate of reaction?

- Increasing the frequency of collisions
- Increasing the energy of collisions

How do you increase the frequency of collisions?

- Increasing concentration or pressure
- Increasing surface area

Increasing Concentration or Pressure

When the concentration of a solution increases, there are more reactant particles moving randomly in a given volume of solution, increasing frequency of collisions and thus successful collisions.

Increasing Surface Area

- Only surface particles react. Increasing surface area (e.g., breaking into smaller pieces) exposes more particles which increases collision frequency, thus increasing reaction rate

How do you increase the energy of collisions?

- Increasing temperature

Increasing temperature for increasing energy of collisions

- Increasing temperature, increases particles kinetic energy.
- more particles have enough energy to overcome the activation energy, increasing frequency of successful collisions.

Homogeneous Catalysts

same physical state as the reactants and products of the reaction

Heterogeneous Catalysts

different physical state to the reactants and products of the reaction