2. Mixtures – a review
• Mixtures are made by physically mixing
two or more things together. No chemical
bonds are made.
• Two types:
– Heterogeneous
– Homogeneous
3. Heterogeneous Mixture
• “Hetero” means “different”
• You can see the different parts of the
mixture. There can be different states
(solid, liquid, gas).
• Can be separated by filtering.
• Example:
4. Homogeneous Mixture
• “Homo” means the same
• It all looks like the same material, and there
is only one state.
- We call them solutions.
• Example:
Salt Water
5. Solution
• Can be physically separated
• Dissolve: When a solid becomes part of a liquid.
• Made of solutes and solvents
the thing being dissolved
the thing that takes the solute
Sugar
(solute)
Water
(solvent)
Sugar Water
(solution)
Salt water is a
solution. How can it
be physically
separated?
6. Solution
• The solvent is the biggest part of the
solution and the solute is the smallest part of
the solution
S O L V E N T
S O L U T E
7. Types of Solutions
Gaseous solutions: air = Oxygen + Nitrogen
Liquid solutions: drinks = mix + water
Solid solutions: alloys = steel, brass, etc
8. Concentration
• Concentration = How much of the
solute is dissolved.
•The solution is dilute if it
has a low concentration of
solute.
•The solution is
concentrated if it has a high
concentration of solute.
10. Things that change how quickly solids
dissolve
Temperaturee
increased temperature makes
solids dissolve faster
Shaking
shaking makes
solids to dissolve faster
smaller particles dissolve
Faster because they have
more surface area
Particle Sizee
11. • Miscible liquids can easily mix with each
other.
• Immiscible liquids cannot mix with each
other.
Chemistry-Borders
14. Molarity
• Molarity is the concentration of a
solution = moles of solute per liter of
solution.
Molarity (M) = moles of solute
Liters of solution
15. Molarity
M = moles (solute)
L (solution)
• Example 1: What is the molarity of a solution
that has 2.3 moles of sodium chloride in 0.45
liters of solution?
2.3 moles NaCl = 5.1M NaCl
0.45 L
16. Molarity
M = moles (solute)
L (solution)
• Example 2: How many moles of Na2CO3 are there
in 10.0 L of 2.0 M solution?
moles = M x L
10.0 L x 2.0 M
= 20.0 moles Na2CO3
17. Molarity
M = moles (solute)
L (solution)
• Example 3: How many moles of KNO3 are needed
to make 450 mL of 1.5 M solution?
moles = M x L
0.45 x 1.5
= .675 moles KNO3
19. Dilutions and Molarity
• Use this formula to make a more dilute
solution from a concentrated solution
Molarity1 x Volume1 = Molarity2 x Volume2
(Concentrated) (Dilute)
(before) = (after)
M1V1 = M2V2
20. Example 1
How many liters of 2.5 M HCl are
needed to make 1.5 L of 1.0 M HCl?
M1V1 = M2V2
M1 = 2.5 M
V1 = ?
M2 = 1.0 M
V2 = 1.5 L
(2.5M) V1 = (1.0M) (1.5 L)
2.5M
2.5M
= 0.60L
21. Example 2
• 250.0 mL of a 0.500 M HCl solution needs
to be made. What volume of 12.0 M HCl is
needed to make it?
M1V1 = M2V2
M1 = 12 M
V1 = ?
M2 =0.5 M
V2 = 250mL
V1 = 10.4mL
31. Worksheets 2 + 3
• Finish the worksheets in DingTalk and
send it back to me.
• Then study on Quizlet:
• https://quizlet.com/_ckr2c2?x=1qqt&i=3x9
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