Graphing rates of reaction

Steps for the graph

Time is the X axis

Product is Y axis

Label axis and units

Mark points carefully

Draw line of best fit

Do not extrapolate

How do we know the reaction is finished

When the line goes horizontal

How do we know the rate

Rate is proportional to the slope of the line.

Steeper is faster.

Why is rate fastest at the start

Slows down as reactant concentration drops as the yare being used up.

Formula for average rate

Amount of product/period of time

What is the instantaneous rate

The rate at any moment

Steps for calculating instantaneous rate

Draw tangeant to the curve, touching time you want rate at.

Make a right angled triangle.

Find slope of hypotenuse.

Activation energy

Minimum energy colliding particles must have in order to react

factors affecting rate of reaction

Temperature

Concentration

Particle size

Nature of reactant

Catalyst presence

How does temperature affect

Higher the temperature, the more particles that have activation energy.

Generally, 10 degrees rise doubles rate of reaction.

How does concentration affect

Doubling the concentration of one reactant, doubles the rate of reaction.

Increasing concentration results in particles colliding more often and more effective collisions.

How does particle size affect

The smaller the particles, the faster the reaction rate due to a larger surface area.

How does nature of reactant affect

Ionic compounds react very quickly as they are just ions in solution and bonds are not overcome. Covalent compounds react slower due to bonding.

What are effective collisions

one in which molecules collide with sufficient energy and proper orientation, so that a reaction occurs.