Topic 7- Rates of Reaction and Energy Changes Flashcards
What is the rate of reaction?
the speed at which the reaction turns into products
What is the calculation for the rate of reaction?
Rate of reaction= amount of reactant used or produce formed/ time taken
Describe the pattern of the mass of the reactant on a graph
- It starts at the starting mass on the y axis
- Falls rapidly
- Then slow as the reactant progresses (used up less quickly)
Describe the pattern of the volume of product produced on a graph
- Starts at 0 (at beginning there’s no products)
- Quickly increases
- Becomes less steep (as reaction progresses)
- Finally it plateaus
When measuring the rate of reaction what two things can we measure?
- How fast the reactants are being used up
- How fast the products are being formed
What factors affect the rate of reaction?
- Temperature
- Concentration/ pressure
- Surface Area
- Catalyst
What is the collision theory?
- For particles to react, they have to collide with each other with sufficient energy (activation energy)
- Less energy than this = nothing will happen
What two points can increase the rate of reaction? (not factors)
-Amount of energy the particles have
more energy= more energy they can transfer during the collision
-Frequency of collisions
more often particles collide= more the chance of a successful collision
Describe how temperature will affect the rate of reaction
-As temp increases particles gain more energy (move faster)=
more collision
collide with more energy= more likely to exceed activation energy
… higher rate of successful collisions
Describe how concentration/pressure will affect the rate of reaction
-Concentration (liquid) & pressure (gases)
-As concern/pressure increases= more particles per unit of vol
= more frequent collisions
… increases the rate of reaction
