Acids vs. Bases

What is pH? Parts of Hydrogen ions (H+) More H+  lower the pH = very acidic Few H+  higher the pH = very basic

The pH Scale 0 - 4 = strong acid 4.01 – 6.99 = weak acid 7 = neutral 7.01 – 10 = weak base 10.01 – 14 = strong base

Acids Release H+ into water pH 0 – 6.99 Taste Sour Corrosive to Metals (eats them away) Eat away at stones / buildings / statues

Examples pH of 1 -- Hydrochloric Acid / Battery acid pH of 2 -- Stomach Acid pH of 3 – Lemon Juice pH of 4 – Tomatoes / Acid rain pH of 5 – Regular Rain pH of 6 – Milk

Bases Release OH- into water pH 7.01 – 14 Taste Bitter Slippery feeling Corrosive to flesh (eats away skin)

Examples pH of 8 -- Ocean Water pH of 10 – antacids (tums, etc) pH of 11 – Cleaners pH of 12 – Baking soda pH of 13 – Bleach pH of 14 – Drain Cleaner / NaOH

Neutral pH of 7 Only pure H2O (distilled or de-ionized) Tap water does not have neutral pH

To Bring solution to pH of 7 Neutralization To Bring solution to pH of 7 What is needed to neutralize a basic solution? What is needed to neutralize an acidic solution?

Example John has a glass of orange juice. Which of the following would help raise its pH to 7? Milk Rain Water Bleach Sulfuric Acid

Real World Neutralization Acid Rain lowers pH of a lake to 4.5 Most fish, plants and animals die at this pH (all fish die at 4.2 or lower) pH needs to be between 5 – 8 for How do we do raise the pH of a lake to acceptable levels for life?

As rain water becomes more acidic what happens to its pH? The pH increases The pH decreases The pH stays the same It turns into lemonade!

Acid Rain Definition – rain with a pH below 5 Causes of Acid Rain – Sulfur (SO2 , SO4, H2S) from pollution dissolves into rain water - burning fossil fuels (coal, oil, gasoline, diesel, etc.) - volcanic activity - Factory pollution - More SO2 = lower pH = more damage - Affects of CO2 can also lower pH