1. Acids/Bases/ & Acid Rain

2. How to Recognize Acids & Bases
H+ hydrogen ions OH- hydroxide ions w/ a metal*
Ex. HCl, H2SO4, HNO Ex. NaOH, LiOH, Ca(OH)2,
other ex.’s= citrus fruits *visual exception NH3(aq)
other ex= household cleaners
Acids taste sour Bases taste bitter
Litmus test ends RED Litmus test ends Blue

3. How to measure STRENGTH of Acids and Bases
pH scale: power of H+ ions
0 up to 7=Acidic 7= Neutral >7 to 14= Basic
Strong Acids are near 0, Strong Bases near 14

4. Neutralization
Acids react with Bases in a neutralization reaction to form water HOH (and a salt)
Ex. HCl + NaOH  HOH + NaCl
Pure water is neutral; equal concentrations of the H+ and OH- ions
As OH- are added to H’s, HOH or water forms and the pH of the solution “heads UP towards 7”
Ex. Start at pH=4 (acidic; more H’s than OH’s). Add OH-, water forms and final pH can be 6
As H’s are added to OH’s, HOH or water forms and the pH “heads towards DOWN towards 7”

5. Acid Rain Background
CO2 + H2O  H2CO3 carbon dioxide gas reacts with water to form WEAK carbonic acid. Although slightly acidic, this is considered NORMAL rainwater
SO2 + H20  H2SO4 sulfur dioxide gas reacts with water to form sulfuric acid. This is highly acidic and = ACID rain. Rainwater with a pH less than 5.5 is considered Acid Rain. This gas enters the atmosphere mainly from coal power plants and industrial smokestacks
NOx + H2O  HNO3 nitrous oxides react with water to form nitric acid. This is highly acidic and= ACID rain. These gases enter the atmosphere mainly from vehicle emissions

6. Acid Rain

7. Acid Rain’s Effect

8. Acid Rain and Lakes

9. Acid Rain and Forests

10. Acid Rain’s Effect on Stone
Limestone and Marble w/CaCO3 is very susceptible to acid rain
Sandstone, granite, and other materials without CaCO3 is Not affected by acid rain
The lettering on this marble
Stone has been weathered by acid
rain