Flashcards in Day 2 Deck (35):
How is solubility defined?
As the upper limit of solute that can be dissolved in a given amount of solvent at equilibrium.
What is the solubility of a solute?
The concentration of the saturated solution.
What is a saturated solution?
A solution in which the maximum amount of solute has dissolved in the solvent at a given temperature.
What is an unsaturated solution?
A solution in which the solute has completely dissolved in the solvent.
What is an supersaturated solution?
A solution in which the amount of solute dissolved under given conditions exceeds it's supposed upper limit.
What is the Le Châteliers principle?
A principle that states that when a system in chemical equilibrium is stressed, the system will shift in a way that alleviates the stress.
What's an endothermic reaction?
A reaction where heat is absorbed (deltaH > 0)
What is an exothermic reaction?
A reaction where heat is released (deltaH<0)
What is important to remember when it comes to solute-solvent interactions?
Like dissolves like. Strong solute-solvent attractions = greater solubility, weak solute-solvent attractions = lesser solubility.
What is equilibrium?
The state in which the concentrations of the reactants and products have stopped changing in time.
How does temperature effect the solubility of solids in an endothermic reaction?
In an endothermic reaction heat is effectively on the reactant side with the solid.
Increases temperature makes the system shift towards the product side and this make more of the solids dissociated = increased solubility.
How does temperature effect the solubility of solids in an exothermic reaction?
In an exothermic reaction, hear is on the product side with the dissociated ions.
The system shifts toward the reactant side and this results in decreased solubility.
How does temperature affect the solubility of gases?
Increased temperature mean lesser solubility and decreased temperatures mean higher solubility.
What does equilibrium mean?
What's an forward reaction?
When reactants react and forms products.
What's an reversed reaction?
Products change back to the reactants.
When is an reaction reversible?
When it can go back an forth without any extra energy being used.!
What's chemical equilibrium/equilibrium state?
When a reactions forward progress (reactants forming products) is perfectly balanced with the reversed process (products changing back into the reactants)
What can disturb chemical equilibrium?
By changes in the concentration of one of more substances.
Changes by temperature, or pressure.
What is the Le Châtelier's principle?
If a stress is placed on a system at equilibrium, the system will proceed in a direction that minimizes the stress.
How does the Le Châtelier's principle work if there's a change in the concentration of any of the substances?
The reaction will proceed in any direction that forces the system back in balance.
How does pressure affect the equilibrium?
The forward reaction decrease the volume, but the reversed reaction increases the volume.
How does temperature affect the equilibrium?
Endothermic reactions (consume heat)!is favored if heat is added = higher temperatures seems to feed endothermic reactions.
Exothermic reactions (release heat) is better at low temperatures and tend to favor the reversed endothermic reaction.
What happens heat is added to the reaction?
It forces the reaction back to the left.
What happens if heat is removed from the reaction?
It forces the reaction to proceed to the right.
What is electrolytes?
A substance that will conduct electricity when in an aqueous solution or when molten.
What is molten?
Melted (heat has been applied) and it's become a liquid.
What is a solution?
(Uniform mixture) Mixture or substances = homogeneous mixture.
Solution = solute + solvent
What is solute?
What's being dissolved.
What is a solvent?
The substances doing the dissolving.
What is an aqueous solution?
A solution where the solvent is water.
(Something that's dissolved in water)
What is some examples of electrolytes?
All salts (all ionic compounds) and some polar covalent compounds are electrolytes.
What is the equilibrium constant? Keq
A molar ratio of products over reactants at equilibrium.
Keq = [C]c [D]d
What is M (molarity)?
Number of moles of solute per liter of solution = mol/L