Chemistry - Rate of chemical change Flashcards
Name 4 ways you can change the rate of a chemical reaction
Changing surface area
or
Changing the concentration of the substances
or
Changing the temperature
or
Using a catalyst
magnesium + hydrochloric acid –> magnesium _______ + hydrogen
magnesium chloride
A cube of calcium carbonate has six faces.
The side lengths for this cube are all 2mm.
Calculate the total surface area of the calcium carbonate.
2 x 2 = 4
4 x 6 = 24mm²
If a 36mm² cube of calcium carbonate is split into 2 separate lumps, will the reaction be quicker, slower or the same length of time?
Quicker
Do reactions of solids take place inside the solid as well as at the surface of the solid?
No, reactions only take place at the surface of a solid
Increasing the temperature increases the _____ energy of particles
‘Kinetic’ energy
Why do fireworks contain powder not lumps?
Higher surface area so quicker rate of reaction
What does more kinetic energy in particles mean?
Increase in frequency of particle collisions
What is a catalyst?
A substance that speeds up a reaction without getting used up in the process
Why isn’t the catalyst included in the word equation?
It is not being used up in the reaction. It is not reacting with anything, just speeding it up
What is activation energy?
The minimum energy required to start a reaction
Is a lot of a catalyst needed for a reaction?
No
Can a catalyst be used for multiple of the same reaction?
Yes
Are catalysts expensive?
No
