The Four Factors Of Rate Of Reaction Flashcards
Increasing the temperature will increase the rate of reaction. Explain how (5)
– increasing temperature increases speed of the particles
– this is because the heat energy transferred into kinetic energy
– particles will move faster and collide frequently and they’ll collide harder
– now there are more collisions with particles greater than and equal to the activation energy
– this leads to more frequent, successful collision
Increase of concentration will also increase rate. Explain how (3)
– if a solution is more concentrated then there will be a greater amount of particles in a give volume (in the same volume)
– particles will be closer together
– leads to more frequent, successful collisions and more collisions above activation energy so reaction can occur.
Increasing gas pressure will increase rate of reaction. Explain how (3)
– when pressure of gas is increased, the same amount of particles will occupy a smaller space.
– this means particles are closer together
– this leads to more frequent, successful collisions and more collisions above the activation energy
Increasing surface area will also increase rate. Explain how (2)
– breaking a solid up into smaller pieces increases SA and SA:V
– since collisions only happen on the surface of a solid an increased surface area mean that there’s an increase of successful and more frequent collisions
ALTERNATIVELY:
– volume of solid remains the same yet there’s a bigger SA for particles to work on so collisions will have to happen more frequently
ALTERNATIVELY:
– several smaller particles have more surface area than one large particle so there’s more surface area and more room for particle to collide with
– more frequent, successful collisions would happen
Define a catalyst
A catalyst is a substance that speeds up the rate of reaction without being used up in the process. This means it’s not included in the reaction equation
The presence of a catalyst speeds up the rate of reaction. Explain why (2)
–different catalysts are needed for different reactions, but they all do the same thing
– they’ll lower the activation energy needed for a reaction to occur and they’ll provide a different reaction path with a lower activation energy
Do you need to put the catalyst into the reaction equation?
No, since they aren’t used up, they don’t belong in the reaction as they didn’t help in making the products, only speeding up the process
Do catalysts affect the total energy change!
No, they don’t/ they don’t change the overall energy change for a reaction, therefore products will have the same energy as they would without a catalyst. ALL A CATALYST DOES IS LOWER ACTIVATION ENERGY
What do catalysts do for the reaction and the particles in it?
Catalysts provide a diff. reaction pathway for particles and does so by lowering the activation energy boundary
