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pH INDICATORS PRACTICE.

Answer this question for your hypothesis. Do colored materials always react according to the ph of the environment?

Materials

• red cabbage
• 4 redroses
• blender or knife
• boiling water
• 200 ml alcohol
• filter paper (coffee filters work well)
• One large glass beaker or other glass container
• Six 250 mL beakers or othersmall glass containers
• household ammonia (NH3) (windshield cleaner)
• baking soda (sodium bicarbonate, NaHCO3)
• lemon juice (citric acid, C6H8O7)
• vinegar (acetic acid, CH3COOH)
•Yakult
• antacids (melox, sal de uvas, alka seltzer)
• Apple juice
• Orange juice
• Liquid hand soap
• Shampoo
• Vegetal color red

Procedure

1. Chop the cabbage into smallpieces until you have about 2 cups of chopped cabbage. Place the cabbage in a large beaker or other glass container and add boiling water to cover the cabbage. Allow at least ten minutesfor the color to leach out of the cabbage. (Alternatively, you can place about 2 cups of cabbage in a blender, cover it with boiling water, and blend it.)
2. Filter out the plantmaterial to obtain a red-purple-bluish colored liquid. This liquid is at about pH 7. (The exact color you get depends on the pH of the water.)
3. Pour red cabbage indicator into 250 mLbeaker.
4. Prepare the petals of the roses and “bugambilia”, by chopping and pressing them, and the put them into enough alcohol to cover them
5. After the liquid is colored, repeat step2.
6. Prepare another liquid with 100 ml of water and 1 drop of red color.
7. Pour each of the indicators in the test tubes, and add each of the substances in a separate, and observeany change in color. Register your observations.
8. Repeat the same steps with each of the colored liquids.
9. According to your results, indicate the ph order of the substances used.
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