C2.4 Rates of reaction Flashcards
How can the rate of a chemical reaction be found?
Amount of reactant used or Amount of product formed
___________________ ____________________
Time Time
When can chemical reactions occur?
When reacting particles collide with each other and with sufficient energy
What is the activation energy?
The minimum amount of energy particles must have to react
Increasing the pressure of reacting gases…
Increases the frequency of collisions as the particles are more squashed together
Increasing the temperature increases the…
Speed of the reacting particles so that they collide more frequently and energetically
What increases the rate of reaction?
More frequent and harder collisions of the reacting particles
Increasing the concentration of reactants in solutions…
Increases the frequency of collisions as there are more particles of reactant hitting the water molecules which makes collisions more likely
Increasing the surface area of solid reactants…
Increases the frequency of collisions as the particles will have more area to collide against
What do catalysts do?
Change the rate of chemical reactions
Catalysts are not…
Used up during the reaction
Different reactions need…
Different catalysts
Why are catalysts important in industrial processes?
They increase the rates of chemical reactions and therefore reduce the amount of energy needed which reduces the costs
What does the reaction between hydrochloric acid and marble chips show?
Using ground marble chips and powdered chalk is more effective than using big pieces of marbles there is more surface area, increasing the collisions and therefore increasing the rate of reaction
What does the reaction between magnesium metal and dilute hydrochloric acid show?
An increased concentration of hydrochloric acid reacts much quicker with the magnesium than a lower concentration
What does the reaction between sodium thiosulfate and hydrochloric acid show?
When the two react a cloud precipitate is formed, by watching how quickly the precipitate is formed you can see the rate of reaction. With higher temperature the cloudy precipitate forms quicker, showing that and increase in temperature increases the rate of reaction
