Rates of Reactions Flashcards
(17 cards)
Particles react when:
They collide with sufficient kinetic energy a quantity known as activation energy
What is activation energy? 
Minimum amount of energy required to break bonds in reactant particles-which leads to particles reacting when they collide 
What happens if particles collide but they do not have activation energy?
Collision is unsuccessful and doesn’t lead to a chemical reaction
How can a chemical reaction be altered?
By changing how often particles collide and with how much energy
Ways rate of reaction can be changed
Changing temperature of reaction
Changing concentration of solutions
Changing surface area of a solid reactant
Adding a catalyst
What does increasing the temperature do to the reaction?
Gives all of the particles more energy so they can move around quicker 
Does increasing the temperature increase or decrease the rate of reaction?
Increase 
What does increasing the concentration of solutions do to the rate of reaction? 
This means that there will be more particles in the given volume 
Does increasing surface area of a solid reacting increase or decrease rate of reaction? 
Increase 
Definition of a catalyst 
A catalyst is a substance that speeds up the rate of reaction and is unchanged chemically at the end of the reaction
Do catalysts change?
They remain unchanged at the end of the reaction 
How much of a catalyst is needed? 
Only small amounts
Do all catalyst work for all reactions? 
No certain catalysts are used for different reactions
What does a catalyst do? 
It gives the reaction an alternate pathway that requires less energy 
Does increasing the concentration of solutions increase or decrease rate of reaction
Increase
What does increasing the surface area of a solid reactant do to the rate of reaction?
Pieces will have a larger surface area:
There will be more contact between particles of solid and particles of solutions
More collisions are possible so more collisions with activation energy take palace.
Rate of reaction increase
Key phrase: there will be …
More frequent successful collisions
