pH Lab
Title your paper!
pH Lab
Purpose:
To measure the pH of common household products.
To investigate and understand an acid and a base
as well as the effects acids and bases have on
the environment and the body.
Background Information
An acid is a compound that will produce H+ in solution (meaning
the compound has H on the front and will give the H up when
placed in H2O).
A base is a compound that will produce OH- in solution
(meaning that the compound has OH on the end and will give
the OH up when placed in H2O).
We measure the acidity of a substance using the pH scale.
The pH scale is divided into three essential parts; the acidic
region, the neutral region, and the basic region. 07 is
considered acidic. 7 is neutral and 714 is basic.
Background Information
Exposure to some acids or bases can cause harm to the
human body whereas some acids and bases are used
as cosmetics, cleaning materials, and even foods. Acids
and bases can also have an effect on our environment.
The disposal of these chemicals is critical to the health
of the ecosystem around us. In this lab we will explore
acids and bases and identify how these compounds
affect both living and nonliving things as well as the
health of our water systems.
Record
prediction here!
Household
Product
Record pH here!
Prediction
pH
Acid, Base, or
Neutral
Milk of Magnesia
Vinegar
Ammonia
Water
Record name of
household product
here!
Is the product an acid,
base, or neutral?
Liquid Procedures
1. RECORD the common household products in the table.
2. PREDICT if the liquids you will test will be acidic, basic or neutral. In the table,
record your prediction.
3. COLLECT DATA by testing each of the liquids at your lab station.
4. Place 4-5 drops of each solution in a separate well. Remember which solution went
into which well.
5. Each team member will be given one pH strip to test ONE solution. Only 1/2 of the
pH strip should be submerged.
6. Compare the color change to the pH scale and RECORD the pH of the household
product in the table below.
7. Based on the pH determine if the household product is an acid, base, or neutral
and record it in the table below.
No liquid Procedures
1. RECORD the common household products in the table below.
2. PREDICT if the liquids you will test will be acidic, basic or neutral. In
the table below, record your prediction.
3. Watch video about using red cabbage as a pH indicator
4. Using pHet pH simulation, RECORD the pH of the common
household products.
5. Based on the pH determine if the household product is an acid, base,
or neutral and record it in the table below.
pH Scale
Analysis
1. What is an indicator? Explain the indicator used in this lab.
2. Draw a pH scale and place each of the substances you tested in the
appropriate spot. Predict where soda, milk, soap, antacids and lemon juice
would be on the scale.
1 2 3 4 5 6 7 8 9 10 11 12 13 14
3. Why is it important for water to be neutral?
4. How could you increase or decrease the pH of water?
5. How would the pH of the groundwater be affected if large amounts of
ammonia were dumped accidentally? Explain.
6. How would the pH of a stream be affected if car batteries were disposed of
in the stream? How would this affect the aquatic life?
ANSWERS
1.Indicators are chemicals that show whether the given
solution is acidic or basic, by the sudden change of color.
A universal indicator is a mixed indicator of organic
chemicals which not only shows whether the given
solution is acidic or basic, but also shows the approximate
pH values by giving a wide particular color for a specific
value of pH
The three common indicators used in the laboratory are:
Indicator
Litmus
Methyl orange
Phenolphthalein
Final color
Acid
Red
Pink
Colourless
Alkali
Blue
Yellow
Deep pink
ANSWERS
3. The pH of water determines the solubility (amount that can be
dissolved in the water) and biological availability (amount that can be
utilized by aquatic life) of chemical constituents such as nutrients
(phosphorus, nitrogen, and carbon) and heavy metals (lead, copper,
cadmium, etc.).
For example, in addition to affecting how much and what form of
phosphorus is most abundant in the water, pH also determines whether
aquatic life can use it. In the case of heavy metals, the degree to which
they are soluble determines their toxicity.
4. By adding a few drops of alkali to pure water, it's pH increases; and by
adding a few drops of an acid decreases the pH of pure water.
ANSWERS
Now, you figure out 5 & 6 
Groundwater Pollution
Lab