SC140 Elements of Chemistry

This project offers a hands on approach to understanding the acidity of a solution and basic compounds in relation to pH. You may review this topic by reviewing Chapter 6 in Chemistry in Context. By completing this project, you will increase your knowledge of the properties of an acid or base and explain how acid base reactions are important in environmental chemistry.

Acids are classified as strong or weak by their ionization behavior in water. Basic compounds are referred to as alkaline substances and the watery solutions exhibit a slippery feel. The addition of acids or bases is often quantified in terms of pH and different levels of pH are found within common foods and chemicals in our households.

After successfully completing this project you will be able to:
• Identify acids and bases in your household,
• Identify an acid-base reaction and its application.

Instructions for the Experiment
Part I
For Part I of this project, you will need to purchase a package of litmus paper. You may find this at shops specializing in school supplies, gardening or health foods. The cost should be minimal. If you are really adventurous – and the season is right – you can make your own litmus paper by crushing blackberries until they are liquid, pouring the liquid onto construction paper and allowing it to dry.
1. Use your litmus paper, which turns red in acidic solution and blue in basic solution, to determine the acidity of at least 3 various foods, liquids and moist surfaces around your home.
2. Test the pH of your tap water.
3. Obtain soil from a nearby garden or lawn, shake it with a small amount of water, let it settle and then test the acidity of the water above the solids.
4. Make notes regarding each of your findings.

Part II
1. Dissolve some baking soda in a large glass of warm water.
2. Add a couple drops of liquid dish soap and stir.
3. Pour vinegar into this solution.
4. Make notes describing the chemical reaction involved.

Instructions for the Answer (This is the only item you will submit to the grader.)
Write a one-page paper reporting your findings for Part I and Part II of this assignment. Include descriptions of the reactions that occurred with each experiment you conducted.