6.3 Acids and Bases

1. Acids, Bases, and
the pH Scale

2. Acids & Bases
Acids
 Turn litmus paper red
 Taste sour
 active metals (Zn, Fe) to give
Hydrogen gas
Bases
 Turn litmus paper blue
 Taste bitter
 Feel slippery on skin
 React with acids to form water and
ionic compounds called “salts”

3. Acids and Bases

4. Indicators
Substance that changes color
in the presence of an acid or
base (we are using universal
indicator) other examples are
litmus paper, red cabbage
leaves, grape juice,
blueberries.

5. What is the difference?
Acids
Hydrogen ions
(H+, also called
protons)
An acid is a proton
donor
Bases
OH (Hydroxide
ions)
A base is a proton
acceptor

6. pH Scale
Devised by Soren Sorensen in 1909
Scale ranges from 0-14
pH of less than 7 considered acidic
pH of more than 7 considered basic
pH of distilled water (neither acidic or basic) = pH of 7

8. What do Acids and Bases Do?
Both acids and bases, even in dilute solution break down the
protein molecules in cells.
Can get bad burns from acids and bases.
pH of blood must be carefully maintained- if it changes too much
you can go into acidosis or alkalosis- blood can lose it’s ability to
carry oxygen

9. Acids and Bases are used for:
Batteries
Fertilizers
Industry and Construction
Used to make mortar and cement
Oven Cleaner and Drano

10. Directions: Number your notes from 1-14 and place the
following next to the appropriate pH. This is simply a
guess.
Hint: Stomach Fluids (Very Acidic) and Bleach (Strong Base)
Anybody that gets 1-14 correct (100%) will be given an
automatic A on Lab to follow!

11. ANSWERS:
1. Stomach Fluids
2. Lemon Juice
3. Vinegar
4. Tomatoes
5. Coffee
6. Milk
7. Pure Water
8. Blood
9. Baking Soda
10. Borax
11. Rolaids / Tums
12. Household Ammonia
13. Bleach
14. Lye

12. Now, Let’s Sing!
Acids and bases have two different faces,
Two different personalities,
And you gotta find out what they’re all about,
If you want to learn chemistry
Now the first thing you gotta get strait in your head,
Acids turn blue litmus paper to red.
They react with metals with awesome power
They neutralize bases and taste very sour

13. Bases are different from acids, it’s true,
Bases turn red litmus paper to blue
They neutralize acids, fell slippery on skin,
They taste sorta bitter, and are alkaline.
Well, there’s even more to this wonderful tale,
Something we call a pH scale
It numbers from zero up to fourteen,
Those are powers of ten, if you know what I mean.

14. When the pH is 7, then it’s a case,
Where the sample is neither acid nor base
But less than 7?… it’s an acid we say,
More than 7 it’s a base all the way.
Acids and bases?…. Why should you care?
Cause acids and bases are everywhere
You put them on salads, and they get in the rain,
They settle your tummy, and clean out your drain

15. So the next time you’re sitting under some shade,
And you’re sipping a glass full of real lemonade
You’ll notice the sour taste and think in your head
I bet it turns blue litmus paper to red!