Definitions Flashcards
Heat of reaction (delta h)
The net change of chemical potential energy of the system
Exothermic reactions
Reactions which transform chemical potential energy into thermal energy
Endothermic reactions
Reactions which transform thermal energy into chemical potential energy
Heat of exothermic and endothermic
Exothermic reactions release heat and thus increase the temperature of the reaction mixture
Endothermic reactions absorb heat and thus decrease the temperature of the reaction mixture
Activation energy
The minimum energy required to start a chemical reaction OR the energy required to form the activated complex
Activated complex
A high energy, unstable, temporary transition state between the reactants and the products
Reaction rate
The change in concentration per unit time of either a reactant or product
Catalyst
A substance that increases the rate of reaction but remains unchanged at the end of the reaction
Collision theory
A model that explains that a reaction will only proceed when reactant particles collide effectively
Effective collision
One in which the colliding reactant particles have:
- The correct orientation
- Sufficient kinetic energy. Kinetic energy must be greater or equal to EA
