Rates of Reaction

Question 1

rate of reaction equation

Answer 1

reactant used or product formed/time taken

Question 2

what factors affect rate of reaction?

Answer 2

• concentration (liquid) - more particles=more frequent collisions
• pressure (gas) - more particles=more frequent collisions
• surface area (solid) - more area for particles to work on=more frequent collisions
• temperature - higher temp=particles move faster=more frequent collisions
• catalysts - lower activation energy

Question 3

required practical: rate of reaction (disappearing cross+bungs)

Answer 3

disappearing cross
1.

bungs
1.

Question 4

what are reversible reactions?

Answer 4

when products can react to produce original reactants

Question 5

what is equilibrium?

Answer 5

when the forward and backward reactions happen at exactly the same rate in a closed system

Question 6

what is dynamic equilibrium?

Answer 6

both reactions are still happening with no overall effect

Question 7

what does the position of equilibrium show?

Answer 7

• equilibrium to the right=concentration of products higher than concentration of reactants
• equilibrium to the left=concentration of reactants higher than concentration of products

Question 8

what factors affect the position of equilibrium?

Answer 8

temp
pressure (gases)
concentration

Question 9

what is Le Chatelier’s Principle?

Answer 9

• If a system is at equilibrium and a change is made to any of the conditions, then the system responds to counteract the change
• can predict effects of changing conditions of a system in equilibrium

Question 10

changes to concentration

Answer 10

• concentration of a reactant is increased, more products will be formed until equilibrium is reached again
• concentration of a product is decreased, more reactants will
  react until equilibrium is reached again.

Question 11

changes to pressure for gases

Answer 11

• an increase in pressure causes the equilibrium position to
  shift towards the side with the smaller number of molecules as
  shown by the symbol equation for that reaction
• a decrease in pressure causes the equilibrium position to shift
  towards the side with the larger number of molecules as
  shown by the symbol equation for that reactio

Question 12

changes to temp

Answer 12

temperature of a system at equilibrium is increased:
* the relative amount of products at equilibrium increases for an endothermic reaction
* the relative amount of products at equilibrium decreases for an exothermic reaction

temperature of a system at equilibrium is decreased:
* the relative amount of products at equilibrium decreases for an endothermic reaction
* the relative amount of products at equilibrium increases for an exothermic reaction.