1. Chemical Reactions 8 th 5.2 Rates of Chemical Reactions

2. Rates It takes energy to break bonds. It takes energy to break bonds. Energy required to start a chemical reaction is called Activation Energy. Energy required to start a chemical reaction is called Activation Energy. Reaction Rate – the speed of a reaction Reaction Rate – the speed of a reaction Factors that affect reaction rate Factors that affect reaction rate

3. Activation Energy

4. Rates Temperature – increase temp. = increase rate Temperature – increase temp. = increase rate Concentration – larger conc. = increase rate Concentration – larger conc. = increase rate Particle Size – increase part. Size = decrease rate Particle Size – increase part. Size = decrease rate Inhibitors – slows down the speed of a reaction Inhibitors – slows down the speed of a reaction

5. Rates Catalysts – speeds up the speed of a reaction Catalysts – speeds up the speed of a reaction Catalysts don’t affect the outcome of the reaction or the temperature of the overall reaction. Catalysts don’t affect the outcome of the reaction or the temperature of the overall reaction. C 2 H 4 + H 2 + platinum → C 2 H 6 C 2 H 4 + H 2 + platinum → C 2 H 6 Enzymes – large protein molecules that act as catalysts Enzymes – large protein molecules that act as catalysts