Name: _______________________________________________________
Cabbage patcH Lab 10 pts
Introduction:
Liquids all around us have either acidic or basic (alkaline) properties. For example, acids taste sour; while,
bases taste bitter and feel slippery. However, both strong acids and strong bases can be very dangerous and
burn your skin, so it is important to be very careful when using such chemicals. We will use Splash Goggles
for this lab. In order to measure how acidic or basic a liquid is, we will use the pH scale as illustrated below:
The strength of the pH scale is determined by the concentration of hydrogen ions (H+) where a high
concentration of hydrogen ions indicate a low pH and a low concentration of hydrogen ions indicate a high pH.
The pH scale ranges from 1 to 14 where 1 to 6 is classified as acidic, 7 is neutral (neither a base or an acid)
and 8 to 14 is classified as basic.
In this activity, you will use pH indicator strips to test common household liquids and determine their pH
levels. The strips change color when exposed to various liquids. Use the back of the vial to determine the pH
scale. For example, *insert color changes here
Pre-Laboratory Predictions:
Check the appropriate box (Think about
the properties of acids and bases.)
Substance
Lysol
Vinegar
Bleach
Club Soda
Sprite
Baking Soda
Pure Water
Antacid
Tap Water
Acid
Neutral
Base
Procedure
1. Make sure each of the beakers at your bench are thoroughly clean. Rinse with water. Use soap if
necessary!
2. Using a piece of masking tape, label each of the items you will test (Lysol, vinegar, etc.) and place the
tabbed piece of masking tape on the beaker.
3. One by one go up to the cart and take a dropper pipette full of the items. DO NOT CROSS
CONTAMINATE THE PIPPETE AND BE SURE TO PUT THE RIGHT LIQUID IN THE RIGHT
LABELED BEAKER.
4. Dip a different pH strip into each beaker and record the estimated pH using the color scale on the
back of the vial.
5. Thoroughly clean each beaker when you are done. Be sure to remove the tape.*Clean up is part of
your grade.
6. Answer post lab questions.
Substance
Ammonia
Vinegar
Bleach
Gatorade
Ginger Ale
Baking Soda
Pure Water
Antacid
Tap Water
Color
pH
Post Lab Questions:
1) Draw a pH scale below and put each of the 9 substances on the appropriate place in the scale.
2) Which substance (s) was the strongest acid? ____________________________________________
3) Which substance (s) was the weakest acid? ______________________________________________
4) Which substance (s) was the strongest base? ____________________________________________
5) Which substance (s) was the weakest base? ______________________________________________
6) Does a solution with a hydrogen concentration greater than pure water have a pH greater or less than 7?
________________
7) How much does the hydrogen concentration change when you go from an Antacid to pure water?
_______
8) How much more acidic is vinegar than pure water?
9) How much more basic is ammonia than pure water?