1. 19-2 Describing Acids and Bases
19-3 Acids and Bases in Solution

2. Properties of Acids Sour taste
Corrodes metals = chemical reaction that produces hydrogen gas and wears away the metal
Etching
Reactions with carbonates CO32-
Produces carbon dioxide gas
Used to test rocks for carbonates
Reactions with indicators
Indicator = changes color in presence of an acid or base
Ex. Litmus

3. Properties of Bases Bitter taste Slippery feel
Tonic water, soaps, shampoos, detergents
Slippery feel
Soap, shampoo, detergent
Reactions with indicators
Turns litmus paper blue
Reactions of Bases
Don’t react with carbonates to produce carbon dioxide

4. Acids in Solution All acids contain hydrogen ions
In water acids separate into hydrogen ions and a negative ion
HCl H+ + Cl-
Acids turn blue litmus paper red
An acid is any substance that forms hydrogen ions in water
Litmus Paper

5. Bases in Solution All bases contain hydroxide ions (OH-)
In water bases separate into positive ions and hydroxide ions
NaOH Na+ + OH-
Bases turn red litmus paper blue
A base is any substance that forms hydroxide ions in water

6. Strength of Acids and Bases
Strength = how many molecules separate into ions in water
Strong = most molecules separate
Weak = few molecules separate
Strength determines safety. Weak acids are safe to eat/drink, but strong ones are dangerous

7. Measuring pH
pH scale = range from 0-14 and expresses the concentration of hydrogen ions in a solution

8. Indicators Indicators determine the pH of a solution
When the pH is low, the concentration of hydrogen ions is high

9. Main source of acid rain is nitrogen and sulfur oxides in pollution
Effects of acid rain on forest (trees without leaves) and statue before and after being subjected to acid rain

10. Acid Base Reactions Neutralization = acid mixed with a base
Neutralization reaction produces water and a salt (water is pH 7, neutral)