Rates of reactions

Question 1

Collision Theory

Answer 1

For a reaction to occur particles need to collide with enough energy

Question 2

Successful collision

Answer 2

Particles need to have enough energy to reacts

Question 3

Addition of a catalyst

Answer 3

*Doesn’t get used up - no waste
*Only need a small amount
* Speeds up the rate of reaction
-Provide an alternative pathway for the reaction

Question 4

Increasing temperature/ heat

Answer 4

*Increases rate of reaction
*Particles will move faster- collide more often
* The proportion of particles with a high enough energy will be higher
* If there are more collisions there’s more successful collisions per unit time

Question 5

Surface area of a solid

Answer 5

• Chop it up to make the particles smaller
• Smaller the powder the larger the surface area - more particles are exposed - more collisions - more successful collisions - more collisions per unit time

Question 6

Increase concentration of a liquid/ Increase pressure of a gas

Answer 6

As you increase concentration pressure per cm3 it increases the number of collisions - increases successful collisions -more collisions per unit time

Question 7

Ea

Answer 7

Activation energy

Question 8

What changes activation energy

Answer 8

Only catalysts changes the activation energy - provides an alternative pathway