NOTES: ACIDS & BASES
(pages 377 – 381)
1. Acid –
2. Base –
3. Neutralization –
4. Indicator-
5. pH Scale –
0 1 2 3 4 5 6
stomach car battery lemon vinegar coffee milk
acid acid juice
Becomes more ACIDIC
7
NEUTRAL
pure
water
8 9 10 11 12 13 14
soap baking disinfectant household bleach oven sodium
soda ammonia cleaner hydroxide
Becomes more BASIC
RED CABBAGE INDICATOR:
COLOR / pH LEVELpink / pH 1 to 3
red / pH 4 to 6
blue-green / pH 8 to 10
yellow / pH over 12
SUBSTANCE / pH
bleach / 12
vinegar / 4
ammonia / 11
lemon juice / 3
baking soda / 9
NOTES: ACIDS & BASES
- Acid – Any compound that increases the number of hydrogen ions (H+)
when dissolved in water.
- Base – Any compound that increases the number of hydroxide ions (OH-)
when dissolved in water.
- Neutralization – A chemical reaction between an acid and a base.
- Changing an acid or base solution so that it is neutral.
- Indicator- An organic compound that changes color in an acid or base.
- pH Scale – A scale that ranges from 0 to 14 to determine pH.
(see diagram below)
0 1 2 3 4 5 6
stomach car battery lemon vinegar coffee milk
acid acid juice
Becomes more ACIDIC
7
NEUTRAL
pure
water
8 9 10 11 12 13 14
soap baking disinfectant household bleach oven sodium
soda ammonia cleaner hydroxide
Becomes more BASIC
RED CABBAGE INDICATOR ACTIVITY
Directions:
1. Secure proper safety materials. You will wear goggles and aprons at all times during this activity!
2. Locate the six test tubes containing the six different substances provided.
3. Read the Red Cabbage Indicator chart below. Notice that red cabbage juice is an indicator which causes substances to change color based on their ph levels.
4. On your own sheet of paper, copy the Substance pH Chart information.
5. Add two drops of the cabbage juice from the beaker to test tube A. Observe the color change that occurs. Using the table below, record the pH level you observe into the proper box labeled “pH Range”.
6. Repeat step 5 for each of the substances in the test tubes.
7. When you have finished your observations and you have recorded the data into your chart, have one person from your group take the test tube rack to the sink. This person will rinse out each tube using the water faucet.
Red Cabbage Indicator Chart
COLOR / pH LEVELpink / pH 1 to 3
red / pH 4 to 6
blue-green / pH 8 to 10
yellow / pH over 12
Substance pH Chart
Test Tube / SUBSTANCE / pH RangeA / bleach
B / vinegar
C / ammonia
D / lemon juice
E / baking soda
F / water