1. Solutions and Mixtures

2. Warm-Up
What is a mixture?
What is a homogeneous mixture?

3. Focus Questions What is a solution?
What are the differences between unsaturated, saturated, and supersaturated solutions?
What are some of the general properties of an acid?
What are some of the general properties of a base?
What is a neutralization reaction?
What is the pH scale?
How is pH used to describe the concentration of acids and bases?

4. Matter
Matter can be either a pure substance or a mixture of pure substances.
Pure Substance:
A pure substance is a material that is homogeneous and has constant properties throughout the sample. (Elements and compounds)
Examples: water, diamond, gold, table salt (sodium chloride), ethanol
Mixtures
There are two types of mixtures

5. Types of heterogeneous mixtures:
Heterogeneous- a mixture that is not uniform in composition –the parts in the mixture can be separated from one another.
Types of heterogeneous mixtures:
Suspension- a mixture in which the particles settle out when the mixture is allowed to stand.
Examples pond water, fruit salad
colloid- a mixture consisting of tiny particles that are smaller than suspension but larger than solution particles. The particles will scatter light when it passes through.
Emulsion- a colloid in which the liquids do not mix are spread throughout one another.
Examples: mayonnaise, peanut butter

6. Homogeneous mixture-a mixture that is uniform in composition throughout – the parts cannot be separated from one another. Another name for a homogeneous mixture is a solution

7. Solutions
Solution: A type of homogeneous mixture formed when one substance dissolves in another.
There are two parts to a solution
Solute – the substance that is dissolved.
Solvent – the substance that causes the other to dissolve. (Water is usually the solvent.)
Example: Lemonade
What part of the lemonade is the solute?
lemon juice and sugar
What part of the lemonade is the solvent?
water

8. Solubility
Solubility: The maximum amount of a solute that can be dissolved in a given amount of solvent at a given temperature.
Soluble – anything that dissolves in another substance.
Ex: Salt is soluble in water.
Insoluble – anything that does not dissolve in another substance.
Ex: Oil is insoluble in water.

9. What affects solubility
1. Temperature-
Increase temperature, increase solubility.
The molecules move faster at higher temperature causing more collisions therefore dissolving faster.
2. Stirring
Stirring brings more solute into contact with solvent, therefore increasing solubility
3. Crystal Size
Smaller crystals increase surface area. More solvent can come into contact with solute therefore increasing solubility.

10. Conductivity
Conductivity is the measure of a solution’s ability to conduct electricity. The conductivity gives important clues as to the type of solute dissolved. In aqueous (waterbased) solutions, dissolved ionic compounds yield solutions with high conductivity.
All of these solutions are considered strong electrolytes.
Solutions with low conductivity are called weak electrolytes.
Solutions made from covalent compounds have zero conductivity since they dissolve as molecules, not ions. These substances are known as nonelectrolytes.

11. Concentration
Not all solutions have all of the solute that can be dissolved.
A concentrated solution has a large amount of solute.
A dilute solution has a small amount of solute.

12. How much can dissolve?
If you continue adding sugar to lemonade, eventually the point is reached when no more sugar dissolves and the excess granules sink to the bottom of the glass.

13. Types of Solubility
Unsaturated – more solute can be dissolved in the solvent
Saturated – no more solute can be dissolved in the solvent at the current temperature.
Generally, as the temperature of a liquid solvent increases, the amount of solid solute that can dissolve in it also increases.

14. Types of Solubility
Supersaturated –contains more solute than a saturated solution at the same temperature.
Ex: Rock Candy is made in this way.

15. Types of Solubility Solubility Curve
Each line on the graph is called a solubility curve for a particular substance.
You can use a solubility curve to figure out how much solute will dissolve at any temperature given on the graph.

17. Warm-Up
1. A(n) __________ solution is any solution that can dissolve more solute at a given temperature.
A. electrolyte
B. saturated
C. supersaturated
D. unsaturated
The answer is D. A saturated solution contains all the solute it can hold at that temperature, but an unsaturated solution can hold additional solute.

18. Warm-Up 2. What is a solubility curve used for?
Answer: You can use a solubility curve to figure out how much solute will dissolve at any temperature given on the graph.

19. Warm-Up
3. The substance being dissolved in a solution is the __________. A. aqueous phase B. media C. solute D. solvent Answer is C. The solute dissolves into the solvent

20. Acids
An acid is defined by Arrhenius as a substance that dissociates to produce hydrogen ions (H+) in a water solution.
HCl → H++ Cl-

21. Properties of Acids Contains hydrogen Taste sour
Reacts with metals to form hydrogen gas
Reacts with carbonates to form carbon dioxide, water and a salt
Corrode metals
Electrolytes
pH is less than 7
Turns blue litmus paper to red
Mg + 2HCl  MgCl2 + H2
Na2CO3 + 2HCl  CO2 + H2O + 2NaCl
Conducts Electricity

22. ACIDS HCl (hydrochloric acid) - gastric juice
H2SO4 (sulfuric acid) - fertilizer, car batteries
HC2H3O2 (acetic acid) - vinegar
HNO3 (nitric acid) - fertilizers
H3C6H5O7 (citric acid) – fruits
Other common uses: dyes, paints, food preservation & preparation

23. Bases or Alkaline NaOH → Na+ + OH-
A base is defined by Arrhenius as a substance that produces hydroxide ions OH- in a water solution.
NaOH → Na+ + OH-

24. Properties of Bases Contains OH- Taste bitter Electrolytes
Feel soapy, slippery
pH greater than 7
Turns red litmus paper to blue
Reacts with fats/oils to produce soaps
Conducts Electricity

25. BASES NaOH - lye, drain and oven cleaner
Mg(OH)2 - laxative, antacid, milk of magnesia
NaHCO3 – cooking, antacid
KOH – batteries, biodiesel, soaps
Ca(OH)2 – cement
Ba(OH)2 – waste water treatment
NH4OH – food processing

26. Common Bases

27. Warm-Up - Write the questions
1. The pH of an acidic solution is a. Less than 0. c. Less than 7. b. Greater than 14. d. Greater than A solution whose pH is 7 a. Is acidic. c. Is neutral. b. Is basic. d. Is none of the others. 3. Solubility is the _____ amount of a _____ that can be dissolved in a given amount of ______ at a given temperature. a. Least, solute, solvent b. Max, solute, solvent c. Least, solvent, solute d. Max, solvent, solute

28. Warm-Up In order for a solution to form,
one substance must dissolve in another.
the solvent must be water.
a solid must dissolve in a liquid.
a gas must dissolve in a liquid.
A student dissolved equal amounts of salt in equal amounts of warm water, room-temperature water, and ice water. Which of the following is true?
The salt dissolved most quickly in the warm water.
The salt dissolved most quickly in the room-temperature water.
The salt dissolved most quickly in the ice water.
none of the above

29. pH Scale pH
The pH scale is used to determine how acidic or basic a solution is.
measured with a pH meter or an indicator with a wide color range. (Litmus Paper)
Ranges from 0 to 14
7 is neutral

30. Common pH Substances

31. Neutralization Reaction
Note: A salt is an ionic compound
Reaction of acid and a base forms a salt and water – ALWAYS
NaOH + HCl  NaCl + H2O
Acid?
Base?
Salt?
HCl
NaOH
NaCl

32. Neutralization Reaction
2HNO3+ Ba(OH)2  H2O + Ba(NO3)
Acid?
Base?
Salt?
H3PO4
NaOH
Na3PO4

33. Neutralization Reaction
2LiOH + H2SO4  2H2O + Li2SO4
2HClO4 + Ca(OH)2  Ca(ClO4)2 + 2 H2O
KOH + HNO3  H2O + KNO3
H3PO4 + NaOH  H2O + Na3PO4

34. Solutions, Acids, & Bases
Review

35. Review The substance being dissolved is called _________.
The substance doing the dissolving is called __________.
A solution is a ______________ mixture.
A solution that can dissolve more. _________
A solution that can dissolved no more. ___________
A solution that has dissolved more than normal. ________________

36. Review Substances that in solutions have H+ (hydrogen) ions are…
Acids produce what in water solution?
The acid in oranges.
The acids in fertilizers.
The acid in your stomach.
Solutions that have OH- ions are
Bases produce what in solution? (name)

37. Review Base that is in batteries Base in milk of magnesia
Bases have a ______feel and ________ taste.
Acids have a _______ taste.
Acids and bases are both corrosive and react with indicators to produce a _______ change.
Both produce ions in water and are therefore _____________.

38. Review What measures how acidic or basic a substance is? pH measures
1 on the pH scale indicates a ________ acid 7 indicates a substance is________ and 14 indicates a _________ base.
A reaction of an acid and a base is what type of reaction?
What is formed when an acid and base are combined?

39. Warm-Up What is nitric acid used for?
Hydrochloric Acid is your gastric juice in your stomach… what does it help your body do?
Arrhenius defines an acid as something that…..

40. Warm-Up
What is the difference between saturated, unsaturated, & supersaturated?
What can we do with a solubility curve?
If something is insoluble, what does that mean??

41. Warm-Up What is the formula for hydrochloric acid?
If I produce a hydroxide ion, what am I?
I have a bitter taste.
What is the formula for magnesium hydroxide? And is it an acid or a base?
If I can hold more solute, I am called…

42. Warm-Up What is the formula for sulfuric acid?
If I produce a hydrogen ion, what am I?
I have a sour taste.
What is the formula for lithium hydroxide? And is it an acid or a base?
If I have too much solute, I am called…