What is the project about?
Exploring the relationship between acidic and basic compounds.
What are the goals?
- To understand the relationship between acidic, basic, and neutral pH compounds.
- To identify acidic, basic, and neutral pH items in our homes and every day lives.
Materials and Equipment / Ingredients
- Goldenrod Paper
- Cotton balls or Q-tips
- Household ammonia and water mixture
- Plain water
- Vinegar, lemon juice, or citrus slices
- Safety goggles and gloves
- Candle or crayon (white, yellow, or clear)
- Paper and pencil
- Optional: Camera to take pictures
Where can the materials be found?
Goldenrod Paper can be purchased at Office Max, Target, Walmart or online retailers. All other products can be purchased at drug stores, large discount stores, or grocery stores if they are not already on your shelves.
Any item can be classified as an acid, a base, or a neutral substance with a special test- called a litmus test. In chemistry class this test ranks items on a scale from 0 to 14 (0 being the most acidic, 7 = neutral, 14 is the most basic). In this experiment we'll use special paper to help us identify whether an item is an acid or base. The paper is designed to turn red (and look like it is bleeding!) when a very basic substance touches it. It will also turn back to yellow when something acidic touches it (when combined, acids and bases will neutralize each other). If you use a stronger base you will need a strong acid to get the paper back to yellow (neutral).
- What items are acidic?
- What items are basic?
- Did you find any neutral substances (had no effect on the goldenrod paper)?
- What was your strongest base (turned very red right away)?
- What was your strongest acid (returned the paper to yellow right away)?
- BONUS: If you let your paper sit for awhile, why does it slowly turn back to yellow again? (ANSWER: The CO2 in our air is slightly acidic!)
Terms, Concepts and Questions to Start Background Research
pH - A scale of 0 to 14 that measures whether a substance is an acid, neutral, or basic compound (it actually measures the Hydrogen ion concentration).
Litmus Test - A paper that changes color in accordance with the pH of a test substance.
Acid - 0 to 7 on the pH scale, typically sour substances
Basic - 7 to 14 on the pH scale, typically bitter and feel slippery
Neutral - 7 on the pH scale, little taste