Name___________________________Period_____
Acids and Bases pH Lab Answer Sheet
Complete this chart for the Results (#2). Complete the final question below this chart (#10).
Answer all other lab questions (#1 and #3-9) on the back of this chart.
Substance
pH indicator
paper number
Phenol Red (only for vinegar
and lemon juice in mini-cups)
Acid, Base, or
Neutral?
Distilled Water
Lemon soda
Ammonia
Vinegar
Milk
Dish soap
Lemon juice
Cola Soda
Rubbing Alcohol
10) Look at the following formulas for some of the substances. How do their formulas reveal
whether they are acids or bases and did the formulas accurately tell you if they were acids or bases?
Explain.
1. Distilled Water H2O
2. Lemon Soda
(solution – homogeneous mixture – not a pure substance - no chemical formula)
3. Ammonia
NH4OH
4. Vinegar
C2H4O2
5. Milk
(colloid- heterogeneous mixture – not a pure substance - no formula)
6. Dish soap
(solution – homogeneous mixture – not a pure substance – no formula)
7. Lemon Juice
Citric Acid has a formula – C6H8O7
8. Cola Soda
(solution – homogeneous mixture – not a pure substance – no formula)
9. Rubbing Alcohol
C3H8O
When finished: Read and answer questions in Ch 7 Lessons 2 and 3. There could be
questions on FCAT related to this!
ACIDS AND BASES LAB
Purpose: To test common household substances with indicators in order to classify substances as acid,
base, or neutral.
1) Hypothesis: I predict the following substances will be…
acids_________________________________________________________________________
bases_________________________________________________________________________
neutral________________________________________________________________________
Materials:
pH Paper
Goggles
Test Substances
Testing Trays
Toothpicks
Procedure:
For all the test substances complete the following and put your answers in the data table below.
a. Place a few drops of each test substance in the designated well of testing tray. Place the
substances in the order given in the data table.
b. Carefully dip a strip of pH paper into the substance and hold for just a second. Then take it out.
c. Record the color results in the data table.
d. Repeat for each substance.
e. Next, your teacher will add a few drops of phenol red indicator to each substance in the cups.
Mix it up with a toothpick and record the color in the data table.
f. When done bring your testing tray to your teacher. All other materials go in the trash can. KEEP
YOUR GOGGLES ON DURING CLEAN UP!
2) RESULTS: DATA TABLE (on separate paper)
ANALYSIS Questions:
3) What is the pH range for acids, bases, and neutral substances?
Acid pH____________________ Neutral pH___________________ Base pH____________________
4) How can you tell and acid from a base when looking at a chemical formula?
CONCLUSION – Answer all questions below
5) Was your hypothesis correct? If not, explain why?
6) What did you learn about indicators and how they change with acids and bases?
7) How is the pH scale used to classify acids, bases, and neutral substances?
8) Was there a control used in this test? So is this an investigation or an experiment? Explain.
9) What were the independent and dependent variables in this test? List the variables and define why
they are those variables.
10) The question is on your answer sheet.