Rate of Reaction & Collision Theory

ACTIVATION ENERGY AND
COLLISION THEORY

The Collision Theory describes the conditions necessary for a
reaction to take place.

Collision theory states that:

1.

Particles must collide.

2.

They must collide with sufficient energy.

3.

They must collide at the proper orientation.

As the number of collisions increase, the reaction rate increases.

Multiple Choice

What happens if molecules collide but not in the correct orientation

• Molecules always collide correctly

• All collisions result in products

• Explosion

• No reaction

Multiple Choice

Increasing the temperature is a way to add energy to the reaction, how does a higher temperature impact the way molecules move?

• Molecules move FASTER and collide LESS often at higher temperatures

• Molecules move FASTER and collide MORE often at higher temperatures

• Molecules move SLOWER and collide MORE often at higher temperatures

• Molecules move SLOWER and collide LESS often at higher temperatures

Multiple Choice

An effective collision between reactant particles require the particles to have the proper

• charge and mass

• charge and orientation

• energy and mass

• energy and orientation

ACTIVATION ENERGY AND
COLLISION THEORY

►Activation Energy - the minimum amount of energy colliding particles must have in order to
react.

Multiple Choice

The minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.

• Joule (J)

• STP

• catalyst

• activation energy

Multiple Choice

A reaction accompanied by or requiring the absorption of heat.

• endothermic

• exothermic

• catalyst

• activation energy

Multiple Choice

A reaction accompanied by the release of heat.

• endothermic

• exothermic

• catalyst

• activation energy

REACTION RATE

►Reaction Rate - the rate of disappearance of reactant or the rate of
appearance of product.

Multiple Choice

As a reaction progresses, which statement is true

• The concentration of products decreases, and the concentration of reactants increases

• The concentration of reactants decreases, and the concentration of products increases

FACTORS INFLUENCING
REACTION RATE

A. Temperature

If temperature increases, the number of collisions increases,
therefore, the reaction rate increases. Why?

B. Concentration

If the concentration of reactants increases, the number of
collisions increases, therefore, the reaction rate increases.

FACTORS INFLUENCING
REACTION RATE

C. Particle Size

If you decrease the particle size, the surface area
increases, therefore, the reaction rate increases.

D. Catalyst

►A catalyst increases the reaction rate without
being permanently changed.

►A catalyst changes the way a reaction occurs so
that the activation energy required is lower.

FACTORS INFLUENCING REACTION
RATE

Multiple Choice

How does the surface area increase the rate of reaction

• More exposed sites for reactants to collide

• Fewer exposed sites for reactants to collide

Multiple Choice

All of the following increase the rate of reaction EXCEPT

• Addition of a catalyst

• Increasing the temperature

• Increasing the concentration of the limiting reactant

• Decreasing the surface area

Multiple Choice

What does a catalyst do?

• Catalysts are not related to reaction rates

• Keeps reactants apart from one another to bring the reaction rate to zero

• Decreases the rate of reaction by bringing the reactants together in the correct orientation.

• Increases the rate of reaction by bringing the reactants together in the correct orientation.

Multiple Choice

How does temperature affect the rate of a chemical reaction?

• Increasing temperature increases the rate of reaction

• Increasing temperature decreases the rate of reaction

• Temperature does not impact rate of reaction

• Decreasing temperature increases the rate of reaction