How do changes in the frequency of collisions between particles effect the rate of reaction?
Speeds it up - anything that increases the number of successful collisions between reactant particles
how do changes in temperature affect the rate of reaction?
higher temperature- more energy- faster
so particles collide more often
increase in temperature by 10ºc causes the reaction to double
how do changes in surface area affect the rate of reaction?
decreasing the particle size increases the surface area to volume ratio
more surface area is exposed to reactant particles and there is a greater frequency of collisions so the reaction will speed
how does concentration affect the rate of reaction?
more reactant particles in the same volume so the particles are more closely packed together increasing the frequency of collisions and therefore the rate of reaction
how do pressure affect the rate of reaction?
reducing the volume increases the pressure so there is the same number of particles in a smaller volume so the particles are closer together and increases the frequency of collisions and also the rate of reaction
what does a catalyst do?
Speeds up a chemical reaction.
how are catalysts useful?
save money
save time
conserve fossil fuels
reduces CO2 pollution
how exactly do catalysts work?
provide alternative reaction route and requires a lower activation energy but does not alter the overall energy change or the frequency of collisions but more collisions are successful
what is an enzyme?
Proteins that speed up chemical reactions
what is a biological catalyst?
special types of large complex proteins called enzymes
what are catalysts usually?
transition metals and precious metals in the form of powders or pellets to give a larger surface area