CHEMICAL REACTIONS
KINETIC MOLECULAR THEORY Matter is composed of tiny particles called atoms or molecules These particles are always undergoing constant, random (Brownian) movement.
Collision Theory Reactants must collide with the correct orientation and with sufficient energy.
Orientation – position in space
Effect of Collision Energy on Chemical Reactions SUFFICIENT ENERGY = NEW PRODUCTS INSUFFICIENT ENERGY = NO NEW PRODUCT
Reactions must have a minimum activation energy…if too little, no reaction.
A reaction takes place if the energy available is greater than the minimum activation energy.
Exothermic (Exogonic) Reaction = Energy of the Reactants > Energy of the Products
Endogonic (Endothermic) Reactions – Energy of the Reactants < Energy of the Products
STEPS IN CHEMICAL REACTIONS
1. Bond Breaking
2. Formation of Activated Complex – an intermediate product
3. Formation of Product
FACTORS AFFECTING REACTION RATES
1. Nature of Reactants A reaction could only take place if the reactants are reactive enough to form a new product. Ex. Neon gases are inert and will not react with oxygen while sodium metal will burn if exposed to O2 gas.
2. Temperature
3. Concentration of Reactants
Presence of catalyst or inhibitor
Effect of the presence of catalyst on a reaction
END OF TOPIC
Le Chatelier's Principle If a system at equilibrium is altered in a way that disrupts the equilibrium, the system will shift in such a way as to counter the change.
Rates of Reaction for Reversible Reactions
Changes in Concentrations for a Reversible Reaction
Effect of Increased Concentration on Equilibrium
Change in Rates When Reactant Added
Effect of Decreased Concentration on Equilibrium
Change in Rates When Product Removed