1. Acids & Bases
SciencePower 10 (p )

2. Journal Entry #1: Acids & Bases
Copy and answer the question below into your journal.
What is an acid? Give two examples of an acid.
2. What is a base? Give two examples of a base seen in everyday life.
3. What is a pH scale and what is it used for?
**Hint for #1/#2: think of household products or food for examples.
Acid, Base, Salt Simulation:

3. Acids, Bases, and Salts
Scientists often refer to substances as being either acids, bases, or salts.
During scientific experiments, it is important to know what type of substance you are working with, so that you have an idea of how it might react with other elements and chemicals.

4. Acids, Bases, and Salts
Acid: Sour-tasting compound that produces hydrogen ions (H-) when it dissolves in water and has a pH of between
Base: Bitter-tasting, slippery-feeling compound that produces hydroxide ions (OH-) when it dissolves in water and has a pH of between
Salt: An ionic compound that results from the reaction between an acid and a base.
pH (“potential Hydrogen”): The relative acidity (how acidic something is) or alkalinity (how basic something is) of a substance.

5. What is pH? The relative acidity or alkalinity of a substance.
Acidity  How acidic something is
Alkalinity  How basic something is
pH stands for “potential Hydrogen”: The ability of molecules to attract hydrogen ions.
An acidic molecule (acid) has a low ability to attract hydrogen ions  pH of 0-6
An alkaline molecule (base) has a high ability to attract hydrogen ions.  pH of 8-14

6. The pH Scale Common Acids pH Common Bases
                                                                                                                                                                                                         
Common Acids pH
Common Bases
Hydrochloric acid Sulphuric acid Stomach juice Lemons Vinegar Apples Oranges Grapes Sour milk White bread Fresh milk
Human saliva Distilled water Blood plasma Eggs Seawater Borax Milk of magnesia Ammonia water Limewater Caustic soda

7. Litmus Paper – Universal pH Indicator

9. Characteristics of Acids
Identified by the presence of a hydrogen (H) atom usually at the beginning of the chemical formula
HCl
Low pH (below pH of 7)
Turns blue litmus paper to red
Sour taste
Reacts with metals to produce salt & hydrogen
Reacts with carbonate salts to produce carbon dioxide

10. Characteristics of Bases
Identified by hydroxide (OH-) ions
NaOH
pH between
Turns red litmus paper blue
Slippery to the touch
Taste bitter

11. Characteristics of Salts
A salt is formed when an acid and a base are mixed.
This is called an Acid-Base Neutralization reaction.
Salts have a neutral pH of 7

12. Acid, Base, or Salt? – Activity
Classify each of the following substances as either an acid, a base, or a neutral substance.
Lemon Juice (pH 2.3)
Eggs (pH 7.8)
Blood Plasma (ph 7.4)
Apples (pH 3.1)
Water (pH 7)
Limewater (pH 12.4)
Stomach juice (pH 1-3)
Vinegar (pH 2.9)
Acid, Base, Salt Simulation: