1. Chapter 8
8.3 and 8.4
Acids and Bases

2. Acids
Acids are compounds that produce hydronium ions (H3O+) when they dissolve in water.

3. General Properties of Acids
Sour taste
Lemons, grapefruits, and vinegar all contain acid.
2. Reactivity with metals
Acids and metals undergo a single replacement reaction.
Ability to produce color changes in indicators

4. Car batteries, acid rain
Common Acids
Name
Formula
Use
Acetic acid
CH3COOH
Vinegar
Carbonic acid
H2CO3
Carbonated drinks
Hydrochloric acid
HCl
Stomach acid
Nitric acid
HNO3
Fertilizer
Phosphoric acid
H3PO4
Sulfuric acid
H2SO4
Car batteries, acid rain

5. Bases
Bases are compounds that produce hydroxide ions (OH-) when they dissolve in water.

6. General Properties of Bases
Bitter taste
Baking chocolate and cough syrup are bases.
Slippery feel
Soap is a base.
Ability to produce color changes in indicators
Phenolphthalein (another indicator) turns red when a base is added. (colorless w/acid)

7. Common Bases Name Formula Uses Aluminum hydroxide Al(OH)3
Deodorant, antacid
Calcium hydroxide
Ca(OH)2
Concrete, plaster
Magnesium hydroxide
Mg(OH)2
Antacid, laxative
Sodium hydroxide
NaOH
Drain cleaner, soap

8. FYI Fish contains bases that can leave a bitter taste in your mouth.
Squeezing lemon juice (an acid) over the fish neutralizes the base and gets rid of the bitter taste.

9. Neutralization is the reaction between an acid and a base.
Salt and water are produced.

10. Neutralization
(H3O+ + Cl-) + (Na+ + OH-) → 2HOH + (Na+ + Cl-)
Acid base → water + salt
The negative ions in the acid combine with the positive ions in the base and form a salt (ionic compound).
Hydronium ions from the acid combine with hydroxide ions from the base and form water.

11. Common Salts Name Formula Uses Sodium chloride NaCl
Food flavoring, preservative
Sodium carbonate
Na2CO3
Making glass
Potassium chloride
KCl
Salt substitute
Potassium iodide KI
Added to table salt to prevent iodine deficiency
Magnesium chloride
MgCl2
De-icer for roads
Calcium carbonate
CaCO3
Chalk, marble floors
Ammonium nitrate
NH4NO3
Fertilizer, cold packs

12. Proton Donors and Acceptors
Acids are proton donors because they produce H3O+ in water.
H3O+ has lost an electron.
Bases are proton acceptors because they produce OH- in water.
OH- has gained an electron.

13. pH Scale 0 to 14 scale ‹ 7 = acid 7 = neutral › 7 = base
Look at figure 22 on page 247 for a visual description.

14. pH Scale The lower the pH the more H3O+ ions the solution contains.
The higher the pH the less H3O+ ions the solution contains.

15. pH Scale Acid or Base pH Item Neutral 7 Distilled water Strong Acid
0.1
Car battery acid
Strong Base 10
Soap
Weak Acid
6.5
Milk
Weak Base
8.5
Baking soda
Depends on solutes
6-8
Tap water

16. Strong vs Weak
When reactions go to completion rather than reaching equilibrium, strong acids or bases are formed.
Strong acid ‹3
Strong base ›10
Weak acids and bases only slightly ionize or dissociate in water. They do not go to completion.

17. Buffers
A buffer is a solution that is resistant to large changes in pH.
They are made by mixing a weak acid and its salt or a weak base and its salt.

18. Electrolytes
An electrolyte is a substance that ionizes or dissociates into ions when it dissolves in water. They conduct electricity well.
Strong acids and bases are strong electrolytes because they dissociate or ionize almost completely in water.
Electrolytes are found in batteries and fuel cells.