How does rate of reaction change during an experiment?
- Rate of reaction will start of faster, and slow down over time
Measuring rate of reaction
- average rate of reaction = total volume or mass produced/ time taken
- or
- average rate of reaction = total volume or mass reacted/ time taken
- exact rate of reaction at a given time = gradient of the curve
Units for rate of reaction
- cm3/s or g/s
Factors affecting rate of reaction
- higher temperature
- higher concentration of reactants
- higher pressure of gases
- larger surface area
- catalyst
Collision theory
- when there is an increase in
- temperature/ pressure/ concentration/ surface area
- rate of reaction will increase - because -
- this change would cause an increase in the
- frequency of collisions - so there is a
- greater chance of a successful collision
Catalyst
- a catalyst increases rate of reaction
- without getting used up
- by providing an alternative pathway
- with a lower activation energy
Activation energy
- minimum energy needed to
- start a reaction