An acid is a substance that reacts with a base. They are usually identified as a sour tasting chemical. Common acids found in the kitchen are lemons, apple juice, orange juice, vinegar and black coffee. A base is a substance that will neutralize an acid. Common bases found in a kitchen are baking soda and egg whites.
In the 3 Science experiments below kids with work with Acids and Bases.
Question: How Can You Tell an Acid from a Base?
Materials: can of red cabbage, strainer/colander, bowl, 3 glass jars, 1 tablespoon of vinegar, 1 tablespoon of baking soda, 1 tablespoon of distilled water, can opener
Step 1: Open the can of red cabbage, using the strainer/colander drain the cabbage juice over the bowl.
Step 2: Put 2 tablespoons of red cabbage juice into each of the three glass jars.
Step 3: Add 1 tablespoon of vinegar to the first jar, add 1 tablespoon of baking soda to the second jar and add 1 tablespoon of distilled water to the third jar.
Step 4: Watch what happens and record your results. What color did the liquids in the jar turn?
What Happened in the Jars?
The red cabbage juice is a chemical indicator. A chemical indicator is a substance that turns color when other substances are present. In the first jar you added vinegar which is an acid to the red cabbage juice. The red cabbage juice turned redder. The stronger the acid the stronger color the chemical indicator (red cabbage juice) will turn. The baking soda (base) was added to the second jar. You will notice that the chemical indicator (red cabbage juice) turned green. In the third jar you added distilled water. The distilled water is a neutral property. You will notice the the chemical indicator (red cabbage juice) did not change colors.
Question: What Happens When you Mix an Acid with a Base?
Materials: 1 cup water, 1/2 cup vinegar, 1 cup orange juice, 3 teaspoons baking soda, 3 cereal bowls
The orange juice and vinegar are your acids and the baking soda is the base.
Step 1: Pour the water in the first bowl, vinegar in the second bowl and orange juice in the third bowl
Step 2: Pour 1 teaspoon of baking soda into each of the bowls.
Step 3: Watch what happens and record your results.
What Happened in the Bowls?
The bowls with the vinegar and orange juice started to fizz and became bubbly. When the baking soda (a base) combined with the vinegar and the orange juice (the acids) a chemical reaction occurred and a new substance was created carbon dioxide. The fizzing and bubbles tat you see are the carbon dioxide begin released. In the bowl with only water now bubbling or fizzing occurred, why? This is because water is neither a base or and acid. It is a neutral property.
Question: What Happens When You Cook a Vegetable in and Acid or a Base?
Materials: 3 cups of water, 3 small saucepans, 1 1/2 cups frozen broccoli florets, 1 tablespoon lemon juice, 1 teaspoon baking soda.
As with any project that requires a stove, adult supervision is required
The lemon juice with be the acid and the baking soda will be the base in this experiment.
Step 1: Pour 1 cup of water in each of the saucepans.
Step 2: Pour 1/2 cup of the frozen broccoli florets in each of the saucepans.
Step 3: Pour 1 tablespoon of lemon juice in the first saucepan, Pour 1 teaspoon of baking soda in the second saucepan, pour nothing in the third saucepan.
Step 4: Let the broccoli cook for 7 minutes.
Step 5: Watch what happens and record your results.
What Happened to the Broccoli?
The broccoli cooked in the baking soda (the base) will be the mushiest and a bright green color. The broccoli cooked in the lemon juice (the acid) will be a yucky olive green color. The broccoli cooked in the water will stay it’s natural green color.
Why Did the Color Change?
Green vegetables are rich in chlorophyll. Chlorophyll is what gives vegetables and grass their green color. When an acid (the lemon juice) was added to the water to cook the broccoli a chemical reaction occurred between the acid and the chlorophyll, that chemical reaction caused the broccoli to turn that yucky olive green color. When baking soda (the base) was added to the water to cook the broccoli the broccoli became mushy, why? The baking soda destroyed the cell walls of the plant (broccoli) causing to to become very mushy. Nothing happened to the broccoli cooked in the saucepan with just water because water is neither an acid or a base. It is a neutral property.