M3 Topic 3: Rates of Reactions

Question 1

what does collision theory state

Answer 1

for a reaction to occur particles must successfully collide with the correct orientation and with sufficient energy

Question 2

what methods are used to increase the rate of a chemical reaction (5)

Answer 2

increase concentration
increase temperature
increase surface area
increase pressure 
use of a catalyst

Question 3

why does an increase in concentration increase the rate of a chemical reaction

Answer 3

increases the number of particles that are available to react which increases the chance of a successful collision.

Question 4

why does an increase in temperature increase the rate of a chemical reaction

Answer 4

increase the kinetic energy of particles, which increases the frequency of successful particle collisions

Question 5

why does an increase in surface area increase the rate of a chemical reaction

Answer 5

increase the number of exposed particles which increases the frequency of successful collision

Question 6

why does an increase in pressure increase the rate of a chemical reaction

Answer 6

moves the particles closer together which increases the frequency of successful collisions

Question 7

what is activation energy

Answer 7

the minimum amount of energy that collisions must posses for a reaction to occur

Question 8

what are the stages of the energy profile diagram (3)

Answer 8

reactants
transition state
products

Question 9

why do catalysts increase the rate of a chemical reaction

Answer 9

it provides a pathway of lower activation energy giving more reactant sufficient energy to successfully react

Question 10

what is a catalyst

Answer 10

a chemical that change the rate of a chemical reaction but does not become part of the product