Reaction Kinetics. Flashcards
Define activation Energy?
The mínimum Energy needed For a reaction to occur.
Define catalyst?
A substance that speeds up a chemical reaction but is chemically unchanged at the end. They work by providing an altérnate reaction pathway with a lower activation energy.
Define enthalpy change?
A heat change at constant pressure.
Define rate of reaction?
Change in the concentration of a reaction/ product per unit time.
What 3 things must occur for a chemical reaction to occur?
- Reacting particles.
- Correct orientation.
- With sufficient amount of energy.
What is an ineffective collision?
When particles collide in the wrong orientation/ don’t have enough energy / bounce Off each other without causing A chemical reaction. They give no reaction.
What is a successful collision?
A collision occurs when particles collide with sufficient energy to result in a reaction.
What is the collision frequency?
The number of collisions per unit time.
What is an exothermic reaction?
Reactants are higher in energy than products.
What is an endothermic?
The reactants are lower in energy than the products.
Define enthalpy?
Heat change in a constant pressure.
What happens when you increase concentration of reactants?
Inc of concentration of reactants in solution increases race of reaction as there are a greater number of particles available to react. This increases frequency of collisions between particles.
What happens when you increase temp?
Inc temp= inc ke = inc frequency of collisions and greater proportion of collisions will have the energy required to react.
What happens when you inc SA of reactants?
Inc s.a of reactant = greater number of particles exposed and available to react = inc frequency of particle collisions, increasing rate
What happens when You increase pressure of reaction?
Inc pressure = inc frequency of particle collisions = inc rate of reaction.
