1. Acids and Bases

2. What is an Acid?
Acid – a substance that produces H+ (hydrogen ions) in solution. It is the ability to produce the H+ ions that gives acids their characteristic properties.

3. Properties of Acids
Acids taste sour. (never use taste to test for the presence of an acid. They can cause tissue damage.)
Acids are electrolytes and can conduct electricity

4. Properties of Acids
Acids are corrosive – they react strongly with metals and “eat away“ at the metals producing hydrogen gas. Contact with skin may result in severe burns and tissue damage
Acids react with indicators, organic compounds that changes color in a n acid or a base.

5. Acids Affect Indicators, by changing their color
Blue litmus paper turns red in contact with an acid (and red paper stays red).

6. Some Common Acids Name Formula Where Found Acetic acid CH3COOH vinegar
Acetylsalicylic acid
HOOC-C6H4-OOCCH3
aspirin
Ascorbic acid
H2C6O6
citrus fruits
Boric acid
H3BO3
eyewash solutions
Hydrochloric acid
HCl
gastric juice in stomach
Carbonic acid
H2CO3
carbonated drinks
Sulfuric acid
H2SO4
car batteries, fertilizers

7. How are acids used?
sulfuric acid – car batteries, fertilizer, dehydrating agent (removes H2O from materials).
Phosphoric Acid – fertilizers, used in soft drinks. Harmful to environment when added to detergents.
Nitric acid – fertilizers, explosives.
Hydrochloric acid – used to clean surfaces in industry. also known as muriatic acid.

8. What is a Base?
base – substance that produces hydroxide ions, OH-, in a solution.

9. Properties of Bases Most bases are crystalline solids.
In solution, bases feel slippery, like soap.
Bases taste bitter.
Bases are corrosive – contact with skin may result in severe burns and tissue damage
NEVER USE TASTE TO TEST FOR THE PRESENCE OF A BASE. THEY CAN CAUSE TISSUE DAMAGE

10. Properties of Bases Bases are electrolytes and conduct electricity.
Bases react with indicators to produce a predictable color change.

11. Common Bases and Their Uses
Name
Formula
Uses
Aluminum hydroxide
Al(OH)3
deodorant, antacid
Calcium hydroxide
Ca(OH)2
Leather production, manufacture of mortar and plaster
Magnesium hydroxide
Mg(OH)2
laxative, antacid
sodium hydroxide
NaOH
drain cleaner, soap making
Ammonia
NH3
household cleaner, fertilizer,
production of rayon and nylon

12. Strength of Acids and Bases
Strong acids – ionizes almost completely in solution (very soluble)
Weak acids – acid that only partly ionizes in solution (slightly soluble)
Strong base – dissociates completely in solution (very soluble)
Weak base – base that only partly dissociates in solution (slightly soluble)

13. Strength and Concentration
Concentration – the amount of acid or base dissolved in solution (g/100 mL)
Strength – refers to the ease that the acid or base forms ions in solution. The more ions that are produced the stronger the acid or base

14. What is pH?
pH is the measurement of H3O+ (hydronium ions) in solution.
pH is a scale used to measure how acidic or basic a solution is.
Below 7 is acidic
Above 7 is basic
7 is neutral

15. Acids have a pH less than 7
Bases
have a pH greater than 7

16. Acids have a pH less than 7
Bases
have a pH greater than 7