1.6 Chemical Equilibria, Le Chatelier's Principle and Kc Definitions Flashcards
Define Catalyst
A substance that increases the rate of a reaction without being changed in chemical composition or amount. They work by providing an alternate reaction pathway with a lower activation energy.
Define Closed system
A system where there is only heat exchange occurring between the system and its surroundings. No matter can enter or exit the system.
Define Dynamic Equilibrium
Dynamic equilibrium is reached when the rate of the forward reaction of a reversible reaction equals the rate of the backwards reaction. The concentrations of the reactants and products remain constant
Define the Effect of changing concentration on equilibrium
If the concentration of a reactant increases, more products will be formed to re-establish the equilibrium
Define the Effect of changing pressure on equilibrium
If the pressure is increased, the position of equilibrium shifts towards the side with the fewest number of molecules. If the pressure is decreased, the position of equilibrium shifts towards the side with the greatest number of molecules
Define the Effect of changing temperature on equilibrium
If the temperature of a system in equilibrium is increased, there will be an increase in the relative amount of products for an endothermic reaction and a decrease for an exothermic reaction
Define Equilibrium Constant (Kc)
A value that expressed the relationship between the concentration of products and reactants present at equilibrium in a reversible reaction
Define Heterogeneous system
A system where not all the chemicals are in the same phase
Define Homogeneous system
A system where all the chemical are in the same phase
Define Le Chatelier’s principle
If a reaction at equilibrium is subjected to a change in concentration, temperature, or pressure, the position of equilibrium will move to counteract the change
Define Reversible reaction
Reactions in which the products from the reaction can react together to form the original reactants. The direction of reversible reactions can be changed by changing the conditions
