Factors Affecting Rates of Reaction Flashcards
What 4 things does the Rate of Reaction depend on?
Temperature
The concentration of a solution or the pressure of a gas
Surface area - this changes depending on the size of lumps of a solid
The presence of a catalyst
More collisions increases the Rate of a Reaction!
all 4 methods of increasing the rate of a reaction can be explained in terms of increasing the number of successful collisions between the reacting particles:
How does increasing Temperature increase the Rate?
Particles move faster when temperature increases
Faster particles collide more frequently
Faster particles mean more energy they have, so more of the collisions will have enough energy to make the reaction happen
How does increasing the concentration or pressure increase the Rate?
More concentrated means more particles knocking about in the same volume of water
Pressure of a gas is increased means that the same number of particles occupies a smaller space
Collisions between the reactant particles become more frequent
How does increasing the Surface area increase the rate?
If 1 reactant is a solid, then breaking it up into smaller pieces will increase its surface area to volume ratio
This means that for the same volume of the solid, the particles around it will have more area to work on - so there will be collisions more frequently
How does using a Catalyst increase the rate?
Catalyst is a substance that speeds up a reaction without being used up in the reaction itself
They all work by decreasing the activation energy needed for the reaction to occur. They do this by providing an alternative reaction pathway with a lower activation energy
