Rates of reaction introduction

Increasing concentration

Increase the number of collisions in given volume, this will increase the frequency of collisions.

Increasing surface area

Reducing particle size will increase the frequency of collision

Increasing temperature

Increase the frequency and energy of collisions

Adding a catalyst

Provide lower energy route for reaction therefore the reaction rate will increase

What does the term ‘Provide lower energy route’ mean?

Energy required for reaction is lowered

Follow the progress of a reaction

Change in mass, volume of gas

Where will the line be steepest

At the start of a reaction

Why will the line slow down

The reactants get used up

Where will the line become less steep

At the end of the reaction

When does the reaction stop

When all the reactant is used up and the line goes flat

Average rate equation

change in quantity/ change in time

Indicators of a chemical reaction?

Change in pH, change in temperature, effervescence, colour change and precipitation

The rate can be determined by measuring the changes in?

Concentration, mass and volume

How does temperature affect the rate of reaction?

Reactant particles gain more kinetic energy, move faster and collide with greater force

What are successful collisions

Collisions with enough energy to overcome the activation energy barrier and form products

How does concentration affect the rate of reaction?

There are more reactant particles in a given volume, meaning there are more opportunities for effective collisions to occur

How does particle size affect the rate of reaction?

Smaller solid particles have a larger surface area, exposing more reactant particles

What do collisions result in?

A chemical reaction

Variable

Something we can change during a chemical reaction

Rate

A measure of the change of a quantity over a period of time