Rates of Reaction

Increasing the Concentration of Thisulphate increases the rate of reaction because there are more particles of Thisulphate to react with the acid so collisions happen more often (more successful collisions). 

If the Concentration is increased:

• The reactant particles become more crowded
• There is greater chance of the particles colliding
• The rate of reaction increases

The rate of a chemical reaction can be raised by increasing the surface area of a solid reactant.

This is done by cutting the substance into small piece, or by grinding it into powder. If the surface area of a reactant is increased:

• More particles are exposed to the other reactant
• There are more collisions
• The rate of reaction increases

Increasing the temperature means that:

• Particles move faster so they collide more often
• Particles collide with more energy
• Rate of reaction increases

Increasing the pressure on a reaction involving reacting gases increases the rate of reaction. Changing the pressure on a reaction, which involves only solids and liquids, has no effect on the rate.

If the pressure increases:

• The reactant particles become more crowded
• There is greater chance of the particles colliding 
• The rate of reaction increases