Unit 9 Flashcards
a homogeneous mixture of two or more aqueous compounds
solution
substance being dissolved
solute
substance doing the dissolving
solvent
a solution in which the particles of un-dissolved solute are so large that they settle out to the bottom of the container (ex. milk)
suspension
a solution in which the particles are so small that they do not settle out but you can see them floating around in the solution (ex. muddy water)
colloid
when you shine a light from a flashlight, search light or some sort of beam of light (sun) through a colloid, you can see the beam because it bounces off of the particles in the colloid. If it is a solution, no beam will be seen. (ex. lights at night in a swimming pool)
The Tyndall Effect
What is the most common solvent?
Water
the molecule is asymmetrical, and the charges are separated
Polar
the molecule is symmetrical and will not dissolve in water (ex. gasoline, waxes, oil, etc.)
Nonpolar
If two substances will dissolve in each other (oil and gasoline), they are considered ________.
Miscible
If two substances will not dissolve in each other
Immiscible
when a solution breaks apart into ions and conducts an electric current, like table salt or sulfuric acid
Electrolytes
What are three ways to dissolve a solute?
- Agitate the mixture by stirring or some other mechanical method
- Heat the solvent
- Increase the surface area of the solute
very little solute, lots of solvent
unsaturated
almost equal amounts of solute and solvent, a little solute can be seen at the bottom of the container after stirring
saturated
so much solute that there is a lot at the bottom after a lot of stirring/heating
supersaturated
the amount of solute that will dissolve in a given amount of solute in a given amount of solvent at a specific temperature. (MOST of the time, heating the solvent increases solubility but there are times when heating actually decreases solubility. )
Solubility
When you increase the pressure on a gas above a liquid, you increase the solubility of that gas in that liquid. When you increase the temperature, the gas escapes (molecules pull away from each other) ex. carbonated beverages
Henry’s Law
the rapid escape of a gas from a liquid in which it has been dissolved
Effervescence
the attraction of the surface of a liquid to the surface of a solid. This occurs in plants.
Capillary Action
a force that tends to pull adjacent parts of a liquid’s surface together, decreasing the surface area (allows water bugs to walk on water)
Surface Tension
states that a system of equilibrium, when subjected to a stress, shifts in a direction that will relieve the stress on the system. Stress to a system includes changing the temperature, adding or removing reactant or product, etc. (shaking a coke and opening the bottle)
LeChatelier’s Principle
the change in phase from a sold directly to a gas without going through the liquid phase (ex. dry ice)
Sublimation
when like molecules are attracted to each other (ex. mercury/aluminum coins floating on water)
Cohesion
when molecules that are not alike come in contact with each other
Adhesion
moles of solute per kilogram of solvent (m)
Molality
moles of solute per Liter of solution (M)
Molarity
properties depending only on the amount of the solute, not the identity of the solute
Colligative Properties
solutes that do not affect the boiling or freezing point of the solution because they leave the solution
Volatile solutes
Boiling point always goes __ and freezing point always goes ____ when a solute dissolves in a pure solvent.
up, down
