Rate of reaction Flashcards
Define activation energy
Minimum amount of energy required for a successful collision between particles
When will particles react?
- If kinetic energy is higher than activation energy
- If they collide in the correct orientation
What is the rate of reaction?
The amount of product made in a reaction over a specified time period.
How to increase the rate of reaction
- Increase the frequency of collisions
- Increase the proportion of successful collisions
Ways to increase rate of reactions
- Temperature
- Concentration
- Pressure
- Surface area
How can you tell from a graph that rate of reaction is high?
Gradient is steep
rate = (volume)
rate = change in volume / change in time
What is half-life?
The time taken for the concentration of a reactant to fall to half of its original value.
What is the half-life pattern for 1st order reactants?
Half-life is always the same, no matter where you start from. (constant half-lives)
What does a concentration-time graph look like for 0th order reactants?
Straight diagonal line
What is the equation for the rate constant using half-lives (if the half-life is constant)?
k= ln(2) / half-life
units are s-1
What does a rate-concentration graph look like for a 1st order reactant?
Diagonal line
What does a rate-concentration graph look like for a 2nd order reactant?
Curved line
What does a rate-concentration graph look like for a 0th order reactant?
Horizontal line
Why are iodine clock reactions called clock reactions?
The time it takes the solution to instantaneously turn dark blue is a measure of the rate of reaction.
