2. Water – The Universal Solvent
Wednesday, July 11, 2012
3. Water – The Universal Solvent
•Many solutions have water as
the solvent.
Wednesday, July 11, 2012
4. Water – The Universal Solvent
•Many solutions have water as
the solvent.
•These solutions are called an
aqueous solution.
Wednesday, July 11, 2012
5. Water – The Universal Solvent
•Many solutions have water as
the solvent.
•These solutions are called an
aqueous solution.
•Water dissolves many solutes
and so scientists call it the
universal solvent.
Wednesday, July 11, 2012
6. Water – The Universal Solvent
•Many solutions have water as
the solvent.
•These solutions are called an
aqueous solution.
•Water dissolves many solutes
and so scientists call it the
universal solvent.
•Why is water such a great
solvent? Let’s find out.
Wednesday, July 11, 2012
21. Like
Dissolves
Like
•Polar solvents will dissolve polar solutes.
Wednesday, July 11, 2012
22. Like
Dissolves
Like
•Polar solvents will dissolve polar solutes.
•Nonpolar solvents will dissolve nonpolar
solutes.
Wednesday, July 11, 2012
23. Like
Dissolves
Like
•Polar solvents will dissolve polar solutes.
•Nonpolar solvents will dissolve nonpolar
solutes.
•Polar will not dissolves nonpolar and vice versa.
Wednesday, July 11, 2012
24. Like
Dissolves
Like
•Polar solvents will dissolve polar solutes.
•Nonpolar solvents will dissolve nonpolar
solutes.
•Polar will not dissolves nonpolar and vice versa.
•Think about oil and water. Is the oil polar or
nonpolar?
Wednesday, July 11, 2012
27. How Much Will
Dissolve?
•If you tried to dissolve a lot of sugar in a small glass
of water, not all of the sugar would dissolve.
Wednesday, July 11, 2012
28. How Much Will
Dissolve?
•If you tried to dissolve a lot of sugar in a small glass
of water, not all of the sugar would dissolve.
•Solubility is the measurement of how much
solute dissolves in a given amount of solvent.
Wednesday, July 11, 2012
29. How Much Will
Dissolve?
•If you tried to dissolve a lot of sugar in a small glass
of water, not all of the sugar would dissolve.
•Solubility is the measurement of how much
solute dissolves in a given amount of solvent.
•Solubility is usually describes as how much can
dissolve in 100g of solvent at a given temperature.
Wednesday, July 11, 2012
30. Solubility
in a
Liquid-Solid
Solution
Wednesday, July 11, 2012
31. Solubility
in a
Liquid-Solid
Solution
Temperature is
included here
because the
solubility of a
solute changes as
the temperature of
the solvent
changes.
Wednesday, July 11, 2012
32. Solubility
in a
Liquid-Solid
Solution
Wednesday, July 11, 2012
33. Solubility
in a
Liquid-Solid
Solution
As you heat
water, you can
dissolve sugar in
water faster rate,
but also more
sugar will
dissolve.
Wednesday, July 11, 2012
34. Solubility
in a
Liquid-Gas
Solution
Wednesday, July 11, 2012
35. Solubility
in a
Liquid-Gas
Solution
In a liquid-gas solution,
the opposite is true.
Wednesday, July 11, 2012
36. Solubility
in a
Liquid-Gas
Solution
In a liquid-gas solution,
the opposite is true.
As the temperature
increases, the solubility
decreases.
Wednesday, July 11, 2012
37. Solubility
in a
Liquid-Gas
Solution
Wednesday, July 11, 2012
38. Solubility
in a
Liquid-Gas
Solution
This is because the
water molecules will
be moving faster at
higher temperatures.
This movement will
bump the gas out of
the solution, therefore
decreases solubility.
Wednesday, July 11, 2012
40. Saturated Solutions
•If you add calcium
carbonate to 100g of water
at 25˚C, only 0.0014g will
dissolve. No more can
dissolve.
Wednesday, July 11, 2012
41. Saturated Solutions
•If you add calcium
carbonate to 100g of water
at 25˚C, only 0.0014g will
dissolve. No more can
dissolve.
•This solution is called a
saturated solution.
Wednesday, July 11, 2012
42. Saturated Solutions
•If you add calcium
carbonate to 100g of water
at 25˚C, only 0.0014g will
dissolve. No more can
dissolve.
•This solution is called a
saturated solution.
•If the solution was a liquid-
solid solution, the extra solid
would settle on the bottom
of the container.
Wednesday, July 11, 2012
44. Saturated Solutions
•The solubility of sugar in 100g of water at
25˚C is 204g.
Wednesday, July 11, 2012
45. Saturated Solutions
•The solubility of sugar in 100g of water at
25˚C is 204g.
•If you had a solution with 50g of sugar in 100g
of water, the solution is called unsaturated.
More solute could dissolve.
Wednesday, July 11, 2012
47. Saturated Solutions
•A hot solvent can
usually hold more
solute then a
cooler one.
Wednesday, July 11, 2012
48. Saturated Solutions
•A hot solvent can
usually hold more
solute then a
cooler one.
•If a saturated
solution cools, some
of the solute can fall
out of the solution.
Wednesday, July 11, 2012
51. Saturated Solutions
•A hot solvent can usually hold more solute then
a cooler one.
Wednesday, July 11, 2012
52. Saturated Solutions
•A hot solvent can usually hold more solute then
a cooler one.
•If a saturated solution cools, some of the solute
can fall out of the solution.
Wednesday, July 11, 2012
53. Saturated Solutions
•A hot solvent can usually hold more solute then
a cooler one.
•If a saturated solution cools, some of the solute
can fall out of the solution.
• But if the solution is cooled slowly,
sometimes the excess solute remains dissolved for
a period of time. This solution is called
supersaturated.
Wednesday, July 11, 2012
55. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
Wednesday, July 11, 2012
56. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
Wednesday, July 11, 2012
57. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
Wednesday, July 11, 2012
58. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
✴it is stirred
Wednesday, July 11, 2012
59. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
✴it is stirred
✴it is shaken
Wednesday, July 11, 2012
60. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
✴it is stirred
✴it is shaken
✴the temperature is increased
Wednesday, July 11, 2012
61. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
✴it is stirred
✴it is shaken
✴the temperature is increased
•How exactly do these factors help?
Wednesday, July 11, 2012
62. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
✴it is stirred
✴it is shaken
✴the temperature is increased
•How exactly do these factors help?
✴They increase the rate at which the surfaces of the
solute come into contact with the solvent.
Wednesday, July 11, 2012
63. Rate of Dissolving
•Solubility does not tell you how fast a solute will
dissolve.
•Some solutes will dissolve quickly, others take a long time
to dissolve.
•A solution dissolves faster when:
✴it is stirred
✴it is shaken
✴the temperature is increased
•How exactly do these factors help?
✴They increase the rate at which the surfaces of the
solute come into contact with the solvent.
✴Increasing the area of contact between the solute
and the solvent can also increase the rate of
dissolving
Wednesday, July 11, 2012
65. Concentrated!
•The concentration of a solution tells you how
much solute is present compared to the amount of
solvent.
Wednesday, July 11, 2012
66. Concentrated!
•The concentration of a solution tells you how
much solute is present compared to the amount of
solvent.
•When you are comparing the concentrations of
two solutions with the same type of solute and
solvent, you can use a simple description such as:
dilute or concentrated.
Wednesday, July 11, 2012
67. Concentrated!
•The Dead Sea is
5+ times saltier than
Earth's oceans. As
water evaporates,
salt is left behind.
When the
saturation point is
reached, the salt
forms these pillars.
Wednesday, July 11, 2012
68. Measuring
Concentrations
•One way to give the
concentration is by using the
percentage of the volume
of the solution that is made
up of the solute.
Wednesday, July 11, 2012
69. Effects on Solute Particles
•Solute particles affect the physical properties
of the solvent, such as the boiling point or the
freezing point.
Wednesday, July 11, 2012
70. Effects on Solute Particles
•Adding a solute, such as NaCl, changes the way
the water molecules can arrange themselves. The
solute gets in the way.
Wednesday, July 11, 2012
71. Effects on Solute Particles
•To overcome this interference of the solute, a
lower temperature is needed for the solvent to
freeze.
Wednesday, July 11, 2012
72. Effects on Solute Particles
•When a solvent begins to boil, the solvent
molecules are gaining enough energy to move
from the liquid state to the gaseous state.
Wednesday, July 11, 2012
73. Effects on Solute Particles
•When a solute is introduced, its particles
interfere with the evaporation of the solvent
particles.
Wednesday, July 11, 2012
74. Effects on Solute Particles
•For water and NaCl, the NaCl will block the
H2O from escaping the liquid and becoming a
gas.
Wednesday, July 11, 2012
75. Effects on Solute Particles
•More energy is needed for the solvent
particles to escape from the liquid, and the
boiling point of the solution will be higher.
Wednesday, July 11, 2012