The rate of Chemical Reactions Flashcards
What are the 5 factors that can affect the rate of reaction?
Concentration
Pressure
Surface Area
Temperature
Catalyst
What is the collision theory?
Chemical reactions only occur when the reactant particle collides with sufficient energy to react.
What is activation energy?
The minimum amount of energy that particles need to react/collide.
Why does an increase of concentration, increase the rate of reaction?
the number of particles in the same volume increases, so the frequency of successful collisions increases
Why does an increase of pressure, increase the rate of reaction?
The volume decreases and the particles are closer together. Frequency of successful collisions increases.
Why does an increase of surface area, increases the rate of reaction?
The number of particles available to react increases. The frequency of successful collisions increases.
Why does an increase of temperature, increase the rate of reaction?
a greater proportion of molecules have the activation energy.
Why does the use of a catalyst increase the rate of reaction?
It provides an alternative route for the reaction which has lower activation energy.
How to calculate the mean rate of reaction?
quantity of reactant used or quantity of product formed / time taken
What does it mean if the curve in the line is the steepest?
the reaction is the fastest
What does it mean if the curve in the line is less steep?
The reaction is starting to slow down
What does it mean if the curve turns flat?
The reaction has stopped.
What is a way to measure the rate of reaction? (PRACTICAL)
You could put the flask on a balance, add the reactants and cotton wool stopper so gas does not get released. Start a clock and record the mass of the flask every 30s until the mass is constant.
