Pg. 77-78 of composition notebook

Acid: Substance that donates Hydrogen ions
(H+) to a solution.
 Or forms H3O+ (hydronium ions) with water

Base: Substance that donates hydroxide ions
(OH-) to a solution.
H2O
Water
H+
hydrogen ion
+
OH-
+ hydroxide ion





pH is a way to measure the amount of acid in
solution
Scale ranges from 0 to 14
A pH of 7 = neutral (neither acidic nor basic)
pH below 7 is acidic
pH greater than 7 is basic




Examples: Acetic acid (vinegar), carbonic
acid (carbonated beverages), hydrochloric
acid (stomach acid), lemon juice
Have a sour taste
React with metals
Produce color changes in indicators
 Litmus paper-turns blue litmus paper red




Examples: Aluminum Hydroxide (deodorant),
antacids, sodium hydroxide (soap production,
drain cleaner)
Bitter taste
Slippery feel (think soap)
Color changes in indicators
 Red litmus paper will turn blue
 Phenolphthalein will turn red
1.
2.
3.
What does red and blue litmus paper tell
you about a substance?
Do you need to use both pieces of litmus
paper to sample a substance? Why or why
not?
What would it tell you about a substance
if neither paper changed color?


Question: Which foods and household
substances are acids and which are bases?
Data:
Substance
1-Tap Water
2-Lemon Juice
3-Vinegar
4-Cola
5-Mouth Wash
6-Antacid
7-Coffee
8-Milk
9- Baking Soda
pH Prediction
Actual pH
Substance
Tap water
Liver
homogenate
Initial pH
pH with 1 drop
of acid
pH with 2
drops of acid
pH with 3
drops of acid

WITHOUT looking at your notes (or book, or
discussing with another person), write down
what you remember about acids and bases.

For each substance discuss the following in
complete sentences:
 Share the name and measured pH value of the
substance.
 Explain how the pH of the substance influences its
properties, uses and side effects (or lack thereof).


Based upon your results in part B, what do
you think a function of the liver is? Use your
specific data to support your answer.
Why did we add the acid to water as well?