Mohammed Mohsin-Acid or Base Lab

Testing Household Substances for Acidity or Basicity Name:Mohammed Mohsin
Purpose:
To test substances found regularly in peoples houses for their acidity or basicity level with a pH sensor.
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Materials and Method: See “Acid or Base?” handout, Dr. Cramer’s SNC2D, Winter 2023. Some of the
household substances may be swapped for different ones, depending upon availability. In addition, we
are using a Vernier wireless pH sensor to measure the pH of each solution.
Observations
In part A, the colour changes of various acid-base indicators and actual pH values are noted in Table 1
when added to a known acid, base and neutral water.
Table 1: The effect of acid, base and water on red litmus, blue litmus, and phenolphthalein along with
pH value
Known Red Litmus Blue Litmus Phenolphthalein pH sensor

Substance reading
Stayed Red Turned Red -Stays the same 0.44
Dilute but a little
HCl (aq) cloudy
Turned Blue Stayed Blue -Turned to 12.53

Dilute Magenta
NaOH (aq)
Stayed Red Stayed Blue Nothing 6.72

Distilled
water (l)
In Part B, the colour changes of the various indicators along with the actual pH value of household substances
are noted in Table 2
Table 2: Results of household substances tested with indicators and a pH sensor
Household substance Red Litmus Blue Litmus Phenolphthalein pH reading

Lemon Juice Stays Red Turns Red Nothing 2.7(Very Acidic)
Pepsi Stays Red Turns Red Nothing 2.8(Very Acidic)
Milk Stays Red Turns slightly Red Nothing 6.2(Slightly Acidic)
Ivory Dish Soap Turns slightly Blue Stays Blue Nothing 8(Slightly Basic)
Shampoo Stays Red Turns Slightly Red Nothing 6.6(Slightly Acidic)
Carbonated Mineral Stays Red Stays Blue Nothing 5.8(Slightly Acidic)

Water
Windex Turns Blue Stays Blue Turns into Magenta 10.6(Basic)
Bleach Turns White Turns White Turns from Magenta 10.79(Basic)

to colourless
Apple Juice Stays Red Turns Red Nothing 4.2(Acidic)
Discussion
1. How does each indicator behave in an acid, a base, or a neutral solution?
● Red litmus: stays red in an acid, turns blue in a base, and stays red in a neutral solution.
● Blue litmus: turns red in an acid, stays blue in a base, and stays blue in a neutral solution.
● Phenolphthalein: turns colorless in an acid, turns pink/magenta in a base, and stays colorless in a neutral
solution.
2. Which of the household substances were acids? Which were bases? Which tested neutral?
Acids:
● Lemon Juice (pH 2.7): tested acidic with red litmus staying red and blue litmus turning red.
● Pepsi (pH 2.8): tested acidic with red litmus staying red and blue litmus turning red.
● Apple Juice (pH 4.2): tested acidic with red litmus staying red and turning red.
Neutral:
● Ivory Dish Soap (pH 8): tested neutral with phenolphthalein indicating nothing.
● Carbonated Mineral Water (pH 5.8): tested neutral with phenolphthalein indicating nothing.
Bases:
● Milk (pH 6.2): tested slightly acidic with red litmus staying red and slightly turning red.
● Shampoo (pH 6.6): tested slightly acidic with red litmus staying red and slightly turning red.
● Windex (pH 10.6): tested basic with blue litmus turning blue, staying blue, and phenolphthalein turning
magenta.
● Bleach (pH 10.79): tested slightly basic with blue litmus turning white, staying white, and
phenolphthalein turning from magenta to colorless.
3. Why is it important to be able to identify a very acidic or a very basic solution?
It is important to be able to identify a very acidic or a very basic solution because the nature of the liquid often
determines its use . For example, stomach liquids need to be acidic in order to break down food, while basic
solutions can be used for cleaning and neutralizing acidic spills. Additionally, pH is a very important
measurement in determining water quality.
4. Which of your solutions was the most acidic and most basic?
The lemon juice was the most acidic with a pH of 2.7 and bleach was the most basic with a pH of 10.7
5. Organize your solutions according to their acidity or basicity.
Most acidic:
● Lemon juice (pH 2.7)
● Pepsi (pH 2.8)
● Apple juice (pH 4.2)
● Carbonated mineral water (pH 5.8)
● Milk (pH 6.2)
● Shampoo (pH 6.6)
Most basic:
● Ivory dish soap (pH 8)
● Windex (pH 10.6)
● Bleach (pH 10.79)
Sources of Error:
Some potential sources of Error could be;
● Contamination: Solutions can become contaminated with other substances, which can alter/change their
pH values. For example, if a solution is exposed to air, it can absorb carbon dioxide and become more
acidic.
● Calibration: The pH meter used to measure the pH of a solution needs to be calibrated regularly to ensure
accurate readings. If the meter is not calibrated correctly, the pH values obtained may be inaccurate.
● Human error: Errors can occur when measuring the volume of the solutions or adding the indicator to the
solutions. Additionally, the timing of when the indicator is added can also impact the results.
● Temperature: The pH of a solution can change with temperature. If the temperature of the solution is not
controlled, it can affect the accuracy of the pH measurements.
Conclusions:
What conclusions are you able to draw from your observations and analysis?
Based on the observations and analysis of the household substances and their corresponding pH values, some
conclusions that can be made are;
● The pH values of household substances can vary widely, from highly acidic (lemon juice and Pepsi) to
highly basic (Windex and bleach), with many substances falling in the slightly acidic or slightly basic
range.
● Different indicators are used to detect the pH of different substances, and each indicator has a specific pH
range in which it can be effective.
● The accuracy of pH measurements can be affected by a number of factors, including contamination,
calibration, human error, and temperature.
● It is important to be able to identify acidic and basic solutions, as they can have different effects on
health, materials, and the environment.

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Testing Household Substances for Acidity or Basicity Name:Mohammed Mohsin

Known Red Litmus Blue Litmus Phenolphthalein pH sensor

Turned Blue Stayed Blue -Turned to 12.53

Stayed Red Stayed Blue Nothing 6.72

Table 2: Results of household substances tested with indicators and a pH sensor

Household substance Red Litmus Blue Litmus Phenolphthalein pH reading

Pepsi Stays Red Turns Red Nothing 2.8(Very Acidic)

Milk Stays Red Turns slightly Red Nothing 6.2(Slightly Acidic)

Shampoo Stays Red Turns Slightly Red Nothing 6.6(Slightly Acidic)

Carbonated Mineral Stays Red Stays Blue Nothing 5.8(Slightly Acidic)

Windex Turns Blue Stays Blue Turns into Magenta 10.6(Basic)

Bleach Turns White Turns White Turns from Magenta 10.79(Basic)

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