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2. 2 How Substances Dissolve  1. Cluster together  2. Water pulls the salt into the solution  3. Spreads out to form Homogenous Solution

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5. 5 Factors Affecting Reaction Rates Most reactions go faster at higher temperatures  Due to kinetic energy-hotter leads to faster particles  Faster particles lead to higher energy which leads to more collisions Example –potato slices cook faster at 200 0 than 100 0

6. 6 Larger surface area speeds up reactions More exposed area the faster the reaction  Example – whole potato will take 30 minutes to cook  Same potato sliced will take 10 minutes  Solids-powder will dissolve quicker in solution than large block of material  Sugar cube vs sugar granules

7. 7 Concentrated (stronger) solutions react faster Small amount of solution will not be effective  Bleach Large amount of solution will be effective

8. 8 Reactions are quicker at higher pressure -Higher pressure - more particles in lead to more collisions  Quicker reactions -Lower pressure - less particles lead to less collisions -Slower reactions -Example – shake up a bottle of soda- increase collisions which increase explosion when opened

9. 9 Massive, bulky molecules react slower The larger the molecule the slower it is Some molecules need to collide on particular side for reaction to happen  This takes many tries before large molecules react Result – compounds react very slowly

10. 10 Catalysts Changes the rate of chemical reactions without being consumed Speeds up or slows down reactions Inhibitor-catalysts that slow reactions  Food Preservatives Solid catalyst- usually speeds up reactions  Catalytic converter on car  More effective with large surface

11. 11 Equilibrium Systems The balance between a chemical reaction and its reverse occurring simultaneously  Carbonated drink in closed container  Burning, rusting and explosions are completed reactions Can’t be reversed

12. 12 La Chatelier’s prinicple of equilibrium A change in chemical equilibrium leads to an equilibrium shift to a new equilibrium  Change is caused by Temperature – Pressure – Concentration-