1. Acids and Bases
Science 10

2. Acids Taste sour (ex. lemons and vinegar) Are corrosive to your skin
React and corrode metals (ex. Magnesium)
Have an H in front of formula (ex. HCl, HBr)
Good conductors of electricity

3. Bases Taste bitter Feel slippery Are also corrosive
Found in many cleaning products (ex. Bleach, oven cleaners, ammonia)
Have an OH on the right side of the formula (ex. Sodium hydroxide, ammonium hydroxide)
Good conductors of electricity

4. Production of Ions
Acids and Bases can conduct electricity because they release ions in solution
Acids release hydrogen ions when dissolved in solution: H+
Bases release hydroxide ions when dissolved in solution: OH-

5. pH (parts of Hydrogen)
The pH of a solution refers to the concentration of ions it has
Testing the pH of a solution is a way of measuring its concentration of hydrogen ions
A high concentration of H+ ions indicates a very acidic solution
Square brackets are used to signify concentration: [H+] and [OH-]
High [H+]=low pH, very acidic
High [OH-]=high pH, very basic

6. pH Scale The strengths of acids and bases is measured on the pH scale
pH below 7=acidic
pH above 7=basic
pH 7=neutral
See Handout: Provincial Exam Data Booklet

7. Neutralization
When an acidic solution is mixed with a basic solution, the solutions can NEUTRALIZE each other. In this case, the pH is 7
[H+] + [OH-]  H2O

8. Using the pH scale 1 Stomach acid has a pH of _____
Tomatoes have a pH of ______.
Each decrease of 1 on the pH scale indicates something is 10X more acidic
Each increase of 1 on the pH scale indicates something is 10X more basic
pH of 4 is ______X more acidic than a pH of 5
pH 3 is ______X more acidic than pH 6
Question: Are tomatoes or stomach acid more acidic, and by how much? 4 10
1000

9. pH Indicators
The pH of acids and bases cannot be determined by sight but through chemicals called INDICATORS
pH indicators change colour based on the solution they are placed in.

10. Examples of Indicators
Litmus Paper
Blue litmus paper turns red in acid (pH 0-6)
Red litmus paper turns blue in base (pH 8-14)
No color change=neutral or pH 7
Phenolphthalein
Colorless in acids
Pink in bases
Color change occurs at pH

11. Using your Data Booklet fill in the following:
Indigo Carmine
Color change occurs at ____________
Changes from ________________ as pH increases
Methyl Orange
Changes from red to yellow as pH increases
Color change occurs at ________________
Methyl Red
Changes from ________________as pH increases
Color change occurs at _________________
Bromythol Blue
Changes from ___________________as pH increases

12. Using your Data Booklet fill in the following:
Indigo Carmine
Color change occurs at pH
Changes from blue to yellow as pH increases
Methyl Orange
Changes from red to yellow as pH increases
Color change occurs at pH
Methyl Red
Color change occurs at pH
Bromythol Blue
Changes from yellow to blue as pH increases
Color change occurs at pH 6-7.6

13. Summary
Properties of Acids
1. Taste

14. Properties of Acids
1. Taste sour 2. Red litmus paper is

15. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is

16. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is

17. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is colourless 5. Bromthymol blue is

18. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is colourless 5. Bromthymol blue is yellow 6. Acid solutions are ______electrical conductors

19. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is colourless 5. Bromthymol blue is yellow 6. Acid solutions are good electrical conductors

20. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is colourless 5. Bromthymol blue is yellow 6. Acid solutions are good electrical conductors 7. ________with active metals (Mg, Zn)

21. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is colourless 5. Bromthymol blue is yellow 6. Acid solutions are good electrical conductors 7. React with active metals (Mg, Zn) 8. Neutralized by

22. Properties of Acids
1. Taste sour 2. Red litmus paper is red 3. Blue litmus paper is red 4. Phenolphthalein is colourless 5. Bromthymol blue is yellow 6. Acid solutions are good electrical conductors 7. React with active metals (Mg, Zn) 8. Neutralized by bases

23. Summary
Properties of Bases
1. Taste

24. Properties of Bases
1. Taste bitter 2. Feel

25. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is

26. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is blue 4. Blue litmus is

27. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is blue 4. Blue litmus is blue 5. Phenolphthalein is

28. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is blue 4. Blue litmus is blue 5. Phenolphthalein is pink 6. Bromthymol blue is

29. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is blue 4. Blue litmus is blue 5. Phenolphthalein is pink 6. Bromthymol blue is blue 7. ______________ with active metals

30. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is blue 4. Blue litmus is blue 5. Phenolphthalein is pink 6. Bromthymol blue is blue 7. Do not react with active metals 8. Neutralized by

31. Properties of Bases
1. Taste bitter 2. Feel slippery (slimy) 3. Red litmus is blue 4. Blue litmus is blue 5. Phenolphthalein is pink 6. Bromthymol blue is blue 7. Do not react with active metals 8. Neutralized by acids

32. Homework Reading Check Page 225 #1-5
pH scale and pH indicators Worksheet (2-sided)
Page 233 #1-8