Red Cabbage
as a
pH Indicator
INTRODUCTION
The concentration of hydrogen ions is called the pH scale.
Low pH corresponds to high hydrogen ion concentration and vice
versa. An acid is a substance that when added to water increases
the concentration of hydrogen ions (lowers the pH). A substance
that reduces the concentration of hydrogen ions (raises the pH) is
called a base.
THE
pH SCALE
The pH scale measures
from pH 1 to pH 14. If a
substance has a pH of 1-5,
it is an acid. If a substance
has a pH of 6-7, it is
neutral. And finally, if a
substance has a pH of 8-14,
it is a base. A pH of 1-3 or
12-14 is considered to be a
strong acid or base.
MATE R IALS
•Two heads of red cabbage
•A blender, chopper, or grater.
•At least 7 beakers (w/ measurements on
the side)
•Medicine droppers
•Medicine cups (or small container w/
metric measurements)
•An orange, sparkling water, shampoo,
vinegar( optional-you can use vinegar that
has been dissolved in distilled water),
baking soda, laundry detergent ( preferably
powder), aspirin (100mg tablets), red
grapes, blueberries, blackberries, carrots,
bar soap, red onions,
•An unlimited supply of water
RED CABBAGE
COLOR SCALE
RED CABBAGE
COLOR SCALE
(By: B. Jackson and K. Glenn)
OTHER
p H I N D I CAT O R S
.
PROCEDURES
1.
.
BLUEBERRY
R E S U LTS
B LAC K B E R R Y
R E S U LTS