Rates of Reaction - C2

Nota:

• Atoms must collide in order to react, but they need energy for the collision to be successful (particles in solids don't have enough energy to collide)

1. Ways to change Rate of Reaction

   Nota:

   • speed of a reaction= 1/time
   1. temperature

      Nota:

      • As you increase the temperature, you increase the amount of kinetic energy in the particle more energy means more movement, increasing the chance of a collision, increasing the rate of reaction.
   2. concentration

      Nota:

      • with a higher concentration, there are more particles in a set amount of space. more particles mean more collisions in a set time, which leads to a faster rate
   3. surface area

      Nota:

      • as you decrease particle size, you increase surface area more surface area means more chance of a sucessful collision which leads to a faster rate of reaction
   4. catalyst

      Nota:

      • A catalyst will speed up a reaction without being used up

      1. Nota:

         • it provides a surface for the reaction This also lowers the activation energy (energy required to start a reaction)  more likely that the collision is sucessful
3. Molar Quantity

   Nota:

   • The calculation to see the amount of energy it takes to break the bonds the energy is measured in KiloJoules (kJ)
4. Endothermic and exothermic reactions

   Nota:

   • every reaction has 2 parts to it breaking bonds=endothermic making bonds=exothermic
   1. Endothermic Reaction

      Nota:

      • Takes in energy from the surroundings Overall an endothermic reaction gives out less energy making bonds than is taken in breaking bonds
   2. Exothermic Reaction

      Nota:

      • Gives out energy to the surroundings Overall an exothermic reaction gives out more energy making bonds than is by breaking bonds
   3. Reversible reactions

      Nota:

      • In a reversible reaction the exothermic and endothermic reactions go in opposite directions