The Rate and Extent of Chemical Change Flashcards
What is activation energy?
The minimum amount of energy required to start a chemical reaction.
What must particles do to react?
Collide with sufficient energy.
What factors affect rate of reaction?
Temperature, Catalysts, Concentration, Surface area, Pressure
What happens to the rate of reaction when pressure is high?
The particles are closer together, so there are more frequent collisions, so the rate of reaction is faster.
What happens to the rate of reaction when pressure is low?
The particles are further apart, so there are less frequent collisions, so the rate of reaction is slower.
What happens to the rate of reaction the higher the surface area is?
There are more frequent collisions so the rate of reaction is higher.
What is a catalyst?
A catalyst is a substance which speeds up the rate of reaction by lowering the activation energy of the reaction.
How does a catalyst lower the activation energy?
It provides an alternate energy pathway.
Why can catalysts be reused?
They are never used up in the reaction.
What happens to the rate of reaction when temperature is increased?
The particles have more energy, so they move faster. Hence, there are more frequent and successful collisions, so the rate of reaction is faster.
What happens to the rate of reaction when temperature is decreased?
The particles have less energy, so they move slower. Hence, there are less frequent and successful collisions, so the rate of reaction is slower.
What happens to the rate of reaction when concentration is high?
There are more particles per unit volume, so there are more frequent collisions, so the rate of reaction is faster.
What happens to the rate of reaction when concentration is low?
There are less particles per unit volume, so there are less frequent collisions, so the rate of reaction is slower.
How can you find the rate of reaction?
Measure the amount of reactants used up over time, or the amount of products made over time.
How can you use precipitation to measure the rate of reaction?
Observe a mark through the solution and measure how long it takes for it to disappear.
