Chemical Equilibrium Flashcards
Closed System?
A system in which mass is conserved inside the system, but energy can enter or leave the system freely. Ex: a coffee mug with a tightly fitted lid. A system/reaction which does not contain a gas does not have to be sealed to be a closed system.
Open System?
A system in which both energy and matter can be exchanged between the system and its surroundings. Ex: a coffee mug left open. An open system cannot reach equilibrium.
Reversible Process?
A reaction in which products can be converted back into reactants. A double arrow is used to represent a reversible process, please highlight it when you see it and be cautious about your understanding when you don’t.
Forward process?
Always known reaction from left to right.
Reverse Process?
Always known as the reaction from right to left.
Equilibrium?
Specifically means that the quantity of each substance remains constant.
Static Equilibrium?
Occurs when no processes are taking place and observable properties (n, p, T) remain constant. Ex: a pen lying on a table.
Dynamic Chemical Equilibrium?
A reversible reaction in which the forward and the reverse reactions are taking place at the same rate and, hence, the concentrations of reactants and products are constant.
What are the two types of reaction phases and define them?
Homogeneous: All substances are in the same phase. Heterogeneous: Not all substances are in the same phase.
Le Chatelier’s Principle?
When an external stress is applied to a system in dynamic chemical equilibrium, the equilibrium point will change in such a way as to counteract the stress. Always state the change that occurred first in your statement.
Common Ion Effect?
The shift in an ionic equilibrium caused by the addition of a solution that contains an ion common to the equilibrium.
Equilibrium Constant?
The ratio between the concentration of products and reactants in a chemical reaction at equilibrium. Kc, has no unit.
Observation?
To notice any changes to the experiment situation using one’s senses. Change in colour, an odor, matter dissolving, etc.
