Rates of Reaction

Rate of reaction

The change in concentration of any one reactant or product in unit time

Experiment for rate of reaction

When monitoring the production id oxygen gas from the e decomposition of hydrogen peroxide using magnesium oxide as a catalyst the follow receptions occurs

Rate of reaction equation

H202 ———> h20 + ½ O2

Average rate of reaction

Total gas produced/ total time taken by

Instantaneous rate of reaction

Is the rate of a reaction at any one particular time during reaction

How to calculate the instantaneous rate of a particular time

1. Draw a tangent to a curve at the time specified

2. Choose 2 points on this tangent

3. Use rise over run to find the slope of the tangent. This is the rate.

Factors affecting rate of reaction

For particles to react they need to collide with a certain amount of energy this is known as the activation energy

1. Nature of reactants

2. Particle size

3. Concentration

4. Presence of catalyst

5. Temperature

Particle size

• smaller particle size means faster reactions because particles have a higher surface area and will collide more often

• This is why powered chemicals react more quickly than large chips or the same substance

For example dust explosion needs combustible dust confined area air and a source of ignition