1. Solutions

2. Solutions
homogeneous mixtures in which one substance is dissolved into another
the “solute” dissolves in the “solvent”
example: Kool-Aid - water is the solvent, the drink mix is the solute

4. A few other terms... Solvation Hydration
When solute particles are surrounded by solvent molecules
Hydration
The name of the solvation process when the solvent is water

7. Solubility a measure of the amount of a substance that will dissolve
depends upon the
solvent used
amount of solvent
temperature

8. Temperature effects solid solute/liquid solvent:
usually, increase in temperature means an increase in solubility
ex: sugar in hot vs. cold water
gas solute/liquid solvent:
usually, increase in temperature means a decrease in solubility
warm pop goes flat faster

11. Rate of Solution
describes how fast a solute dissolves in a given solvent
depends on:
temperature
stirring/agitation
particle size

12. Colligative properties of Solutions
-properties of solutions that are affected by the number of dissolved particles, not the identity of the particles
Example: vapor pressure lowering
The more particles (with little tendency to vaporize) that are added to a solvent, the lower the vapor pressure of the solution becomes

13. Colligative properties of Solutions
Boiling point elevation:
The presence of dissolved particles tends to increase the boiling point of a liquid
The more dissolved particles, the greater the effect
Ocean water would require a higher temperature to boil at than pure water

14. Colligative properties of Solutions
Freezing point depression
The presence of dissolved particles tends to lower the freezing point of a liquid
Salt or other substances are used to melt ice, because as they dissolve into the ice, they lower the freezing point of the ice, and thus even more of the ice melts

15. The “state” of a solution
A solution is described as:
unsaturated
saturated
supersaturated
And as:
concentrated
dilute

16. Unsaturated
the condition in which more solute could be dissolved into the solvent
contains less dissolved solute than a saturated solution

17. Saturated
all the solute that can dissolve in the given amount of solvent at that temperature has been dissolved
if the temperature or amount of solvent changes, the solution may not remain saturated

18. Supersaturated
an unstable condition where more solute is dissolved in a given amount of solvent that should be able to be dissolved
prepared by slowly cooling a hot saturated solution

19. For a given amount, which type of solution contains the LEAST amount of solute?
A. solvated
B. saturated
C. supersaturated
D. unsaturated

20. Concentrated
In a concentrated solution, the amount of solute is large compared to the amount of solvent it is dissolved in
Ex: juices, detergents

21. Dilute In a dilute solution, there is much more solvent than solute
Solutions are “diluted” by adding more solvent

22. A solution can be... concentrated and saturated
concentrated and unsaturated
dilute and saturated
dilute and unsaturated

23. Solutions

24. A few other terms...
two liquids that dissolve into each other are said to be miscible; two that don’t are immiscible
water and oil are immiscible
an insoluble solid is one that does not appreciably dissolve in a given solvent
CaCO3 is insoluble in water

25. Quantify it... The problem is: just how much is “a lot” or “a little”?
We must find a way to quantify the concentration of a solution
There are various ways to do this

26. Quantify it... Percent solution
volume of solute/volume of solvent
mass of solute/mass of solvent
Not directly useful for us - chemists usually work in “moles”

27. Molarity
Molarity of a solution is equal to the number of moles of solute divided by the number of liters of solution
M = mol/L
The larger the molarity, the more concentrated the solution

28. Solutions