Acid and Base Indicators Lab Activity

pH Indicators Lab, pH indicators worksheet

Acid and Base pH Indicators Lab Activity 1

Indicators give scientists a quick way to determine if a solution is an acid or a base without having to taste them or performing time-consuming chemical tests. The most common of these indicators are litmus and universal indicator.

Litmus paper comes in both red and blue colors. To use this paper, simply dip the strip into the liquid and observe any changes. If the substance is a solid/powder, then you will need to dissolve it in a small amount of water first. The table below shows you a summary of what could expect to see.

Type of litmus Acidic Solution Basic Solution
Red litmus Stays red Turns blue
Blue litmus Turns red Stays blue

acid and base pH indicators, acid and base indicators, indicators of acid and base, indicators for acid and base, acid base indicators chart, how do acid base, indicators work, acid base indicators lab answers, acid base indicators change color, natural indicators of acid and base, indicators of acid base and salt, indicators of acid and base class 10, natural acid base indicators list, acid base indicators worksheet answers, acid base indicators theory, why do acid base indicators change color, what are acid base indicators give examples, common acid base indicators worksheet, acid base indicators wikipedia, acid base indicator for visually impaired, acid and base indicators table, acid base indicators at home, acid base indicators in everyday life, how to make natural indicators for acids and bases, what are acid and base indicators, acid base and salt indicators, acid base indicators lab report, examples of acid and base indicators, chemistry acid base, indicators worksheet answers, acid base indicators class 10, acid base indicators ph range, what are acid base indicators used for, Acid Blue Litmus Turns Red, Base Red Litmus Turns Blue, Properties of acids and bases, acid and base indicators lab

Universal Indicator has a much larger color range than litmus. This is due to its ability to determine the strength of the acid or base as well as if the substance is neutral. The table below gives you a summary of what you can expect to see for an acidic, basic, or neutral solution.

Type of solution Color of Universal Indicator
Acid Red, Orange, yellow or light green
Base Dark green, blue, purple, violet
Neutral Green

acid and base pH indicators, acid and base indicators, indicators of acid and base, indicators for acid and base, acid base indicators chart, how do acid base, indicators work, acid base indicators lab answers, acid base indicators change color, natural indicators of acid and base, indicators of acid base and salt, indicators of acid and base class 10, natural acid base indicators list, acid base indicators worksheet answers, acid base indicators theory, why do acid base indicators change color, what are acid base indicators give examples, common acid base indicators worksheet, acid base indicators wikipedia, acid base indicator for visually impaired, acid and base indicators table, acid base indicators at home, acid base indicators in everyday life, how to make natural indicators for acids and bases, what are acid and base indicators, acid base and salt indicators, acid base indicators lab report, examples of acid and base indicators, chemistry acid base, indicators worksheet answers, acid base indicators class 10, acid base indicators ph range, what are acid base indicators used for, pH indicators colors, universal indicator, phenolphthalein, methyl orange, thymol blue, bromothymol blue, phenol red, Acid Blue Litmus Turns Red, Base Red Litmus Turns Blue, Properties of acids and bases, acid and base indicators lab

Acid and Base Indicators Lab Equipment

  • Spot tile
  • Dropper
  • Safety glasses
  • Universal indicator solution or paper
  • Red and blue litmus paper
  • A variety of household chemicals (clearly labelled)

Method

  1. Add 2-3 drops of the chemical being tested to a spot on your tile.

Note: If a substance is solid or powder you will need to add a few drops of water and mix it to form a solution before testing.

  1. Test the chemical with both colors of litmus paper and record your results in the table.
  2. Test the chemical with universal indicator and record results in the table below.

Results/Observations

Household chemical being tested Color in red litmus Color in blue litmus Color in Universal Indicator
     
     
     
     
     

Indicators for Acid and Base Lab Activity 2

Indicators can be obtained from many plant tissues.

Red cabbage juice is a dull purple color and contains a natural pH indicator. This indicator changes colors according to the acidity of the solution due to the presence of the pigment molecule called flavin (an anthocyanin). Flavin is water-soluble and is also found in apple skins, beets, plums, poppies, cornflowers, and grapes.

In very acidic solutions, red cabbage juice indicator will turn a red color. Neutral solutions result in a purplish color. Basic solutions appear in greenish-yellow. Therefore, it is possible to determine the pH of a solution based on the color it turns the anthocyanin pigments in red cabbage juice.

The spice turmeric contains the yellow pigment curcumin which changes from yellow in an acidic and neutral solution to red in basic solutions.

acid and base pH indicators, acid and base indicators, indicators of acid and base, indicators for acid and base, acid base indicators chart, how do acid base, indicators work, acid base indicators lab answers, acid base indicators change color, natural indicators of acid and base, indicators of acid base and salt, indicators of acid and base class 10, natural acid base indicators list, acid base indicators worksheet answers, acid base indicators theory, why do acid base indicators change color, what are acid base indicators give examples, common acid base indicators worksheet, acid base indicators wikipedia, acid base indicator for visually impaired, acid and base indicators table, acid base indicators at home, acid base indicators in everyday life, how to make natural indicators for acids and bases, what are acid and base indicators, acid base and salt indicators, acid base indicators lab report, examples of acid and base indicators, chemistry acid base, indicators worksheet answers, acid base indicators class 10, acid base indicators ph range, what are acid base indicators used for, pH indicators colors, universal indicator, phenolphthalein, methyl orange, thymol blue, bromothymol blue, phenol red, Acid Blue Litmus Turns Red, Base Red Litmus Turns Blue, Properties of acids and bases, acid and base indicators lab acid and base pH indicators, acid and base indicators, indicators of acid and base, indicators for acid and base, acid base indicators chart, how do acid base, indicators work, acid base indicators lab answers, acid base indicators change color, natural indicators of acid and base, indicators of acid base and salt, indicators of acid and base class 10, natural acid base indicators list, acid base indicators worksheet answers, acid base indicators theory, why do acid base indicators change color, what are acid base indicators give examples, common acid base indicators worksheet, acid base indicators wikipedia, acid base indicator for visually impaired, acid and base indicators table, acid base indicators at home, acid base indicators in everyday life, how to make natural indicators for acids and bases, what are acid and base indicators, acid base and salt indicators, acid base indicators lab report, examples of acid and base indicators, chemistry acid base, indicators worksheet answers, acid base indicators class 10, acid base indicators ph range, what are acid base indicators used for, pH indicators colors, universal indicator, phenolphthalein, methyl orange, thymol blue, bromothymol blue, phenol red, Acid Blue Litmus Turns Red, Base Red Litmus Turns Blue, Properties of acids and bases, acid and base indicators lab acid and base pH indicators, acid and base indicators, indicators of acid and base, indicators for acid and base, acid base indicators chart, how do acid base, indicators work, acid base indicators lab answers, acid base indicators change color, natural indicators of acid and base, indicators of acid base and salt, indicators of acid and base class 10, natural acid base indicators list, acid base indicators worksheet answers, acid base indicators theory, why do acid base indicators change color, what are acid base indicators give examples, common acid base indicators worksheet, acid base indicators wikipedia, acid base indicator for visually impaired, acid and base indicators table, acid base indicators at home, acid base indicators in everyday life, how to make natural indicators for acids and bases, what are acid and base indicators, acid base and salt indicators, acid base indicators lab report, examples of acid and base indicators, chemistry acid base, indicators worksheet answers, acid base indicators class 10, acid base indicators ph range, what are acid base indicators used for, pH indicators colors, universal indicator, phenolphthalein, methyl orange, thymol blue, bromothymol blue, phenol red, Acid Blue Litmus Turns Red, Base Red Litmus Turns Blue, Properties of acids and bases, acid and base indicators lab

Indicators for Acid and Base Lab Equipment

  • beakers
  • pipettes/plastic droppers
  • safety glasses
  • spot tiles
  • universal indicator
  • cabbage juice
  • milk
  • soapy water
  • lemon juice
  • vinegar
  • soda
  • tap water
  • baking soda
  • hand sanitizer

Safety

  • Cabbage juice and universal indicator are highly pigmented and stain both clothing and skin.
  • Treat all food stuffs being tested in this lab as contaminated, avoid tasting/eating any samples.
  • Wear safety glasses for the duration of the lab.

Method

  1. Use a pipette to place 2-3 drops of the first sample to be tested into two wells on the spot tile.
  2. In the first well add a drop of universal indicator solution and record any color change.
  3. Using a clean pipette, put 3 drops of cabbage juice into the second well. Record any color changes.
  4. Repeat steps 1-3 for each of the sample substances and record all observations in the table below.  The first row has been completed as an example. 

Results:

Name of substance Observations and Prediction Test with Universal Indicator Color in cabbage juice indicator Acid, base, or neutral?
Example: Grapefruit Juice  Sour tasting – Acid  Orange Pink ACID 
Milk
Soapy water
Lemon juice
Vinegar
Soda
Tap water
Baking soda
Hand sanitizer

The Indicators of Acid and Base Activity:

Students record their predictions and results of the lab activity. Once the activity is finished, discuss the lab activity and answer post-lab questions.

We also provided some of the Resources below for you to use in class. iTeachly Members can access all the content for the activity and the following lesson.

Students must come up with a unanimous answer for each question. Discussing the answers usually, results in some excellent dialogue on this topic.

Here is your Free Content on How to Teach Acid and Base Indicators!

Acid and Base Indicators - PDFs

Acid and Base Indicators Worksheets - Word Docs & PowerPoints

To gain access to our editable content Join the iTeachly Physical Science Teacher Community!
Here you will find hundreds of lessons, a community of teachers for support, and materials that are always up to date with the latest standards.

Want Access to Everything in the Chemical Reactions Unit?

Unit 3 – Chemical Reactions

Simply click the image below to GET ALL OF OUR LESSONS!

NGSS Physical Science Curriculum

Don't Forget to Pin This Lesson on Acid and Base pH Indicators...

Your email address will not be published.