1. Acids and Bases

2. Your standard
SPI Identify the basic properties of acids and bases.

3. Key Words
Acid
Ion
Base
pH scale
Neutral

4. Acids and Bases
Acids and bases have distinct characteristics. We use them every day.
Many substances are classified as an acid or a base.
A substance is an acid or a base depending on the molecules that make it up and what it releases when it is dissolved in water.

6. Ions
An ion is an atom or group of atoms that has a positive or negative charge because it has lost or gained electrons.
Ions are released when acids or bases are dissolved in water.

7. Acids
An acid is a substance that produces hydrogen ions (H+) in a water solution, or in other words, when it is dissolved in water.
Acids can easily be identified by their chemical formulas.
Acids generally have formulas that start with hydrogen such as HCl.

8. Properties of Acids
Always taste sour-such as a lemon which contains citric acid.
Strong acids are corrosive, which means they can eat through plastics, clothing, certain metals, and even skin.
Some acids dissolve proteins. HCl in your stomach digests food.
Can react with certain metals to produce hydrogen gas.

9. Litmus paper in acids will turn/stay red.
When an acid dissolves in water, H+ ions interact with water molecules to form hydronium ions H30+
Can conduct electricity

10. Common Acids Acetic Acid, CH3COOH Vinegar Acetylsalicylic Acid Aspirin
Carbonic Acid, H2CO3 Carbonated Drinks
Hydrochloric Acid, HCl Gastric Juices

11. Nitric Acid, HNO3 Fertilizers
Sulfuric Acid, H2SO4 Manufacture fertilizers
Phosphoric Acid, H3PO3
Fertilizers, detergents & soft drinks

12. Bases Base- a substance that forms hydroxide ions (OH-) in water.
Opposite of acids.

13. Brain Break with Brain Pop

14. Properties of Bases Litmus paper in bases will turn/stay blue.
Many end in OH.
Solids
Feel slippery
Taste bitter
Strong bases are as corrosive as strong acids and can eat through many materials. That is why strong bases such as lye are used to unclog drains, for example.
Can conduct electricity.

15. Common Bases Ammonia, NH3 Cleaner, fertilizer
Aluminum Hydroxide, Al(OH)3 Antacid
Magnesium Hydroxide,Mg(OH)2
Milk of Magnesia
Sodium Hydroxide, NaOH
Soap, Oven Cleaner & Drano

16. Strength of Acids and Bases
Strong Acid- An acid that completely breaks down in solution…releasing H+ ions
Ex: Hydrochloric, Sulfuric & Nitric Acid
Weak Acid- An acid that partly breaks down in solution.
Ex: Acetic and Carbonic Acid

17. Strong Base- A base that completely breaks down in a solution…releasing OH- ions.
Ex: Ammonia
Weak Base- A base that partly breaks down in a solution.
Ex: Sodium hydroxide

18. The pH Scale http://www. brainpop
The pH scale is used to identify how acidic or basic a substance is.
It is numbered from 0 to 14.

19. In an acid, the concentration of H+ ions is greater than the concentration of OH- ions.
The lower the pH value, the stronger the acid.
The opposite is true for bases.
A substance that has a pH greater than 7 is a base and is described as alkaline.
pH means “potential for Hydrogen”

20. When a liquid has a pH of 7, it is said to be neutral.
The concentration of H+ ions equals the concentration of OH- ions.
Pure water has a pH of 7 and is neutral.
Neutral liquids do not have the properties of either acids or bases.

23. Neutralization reactions
When acid and base solutions are mixed in the right proportions, the positive ions from the base combine with the negative ions from the acid.
A new ionic compound forms and water is one of the products.
This is a neutralization reaction.

24. Acid or Base?
Classify the following pH values:
pH = 1
pH = 13
pH = 8
pH = 3
pH = 6
pH = 10

25. Classify the following pH values:
Acid or Base?
Classify the following pH values:
pH = 1
pH = 13
pH = 8
pH = 3
pH = 6
pH = 10
Acid
Base
8th Grade