bbagePreparing and testing a natural indicators AIM: To prepare and testing a natural indicator and applying information about the color changes of indicators to classify and find trends of house hold substance as acidic, neutral or basic. Materials: * Distilled water * 250ml beaker X2 * Test tube X9 * Tripod * Wire Gauze * Bunsen burner * Safety goggles Test Object: * Hydrochloric acid (HCl) * Sodium hydroxide (NaOH) * White Vinegar * Lemon Juice * Baking soda (NaHCO3) * Hair conditioner * Shampoo * Hand soap * Cloudy Ammonia * Dish washing detergent Method: ) Tear off leaves from the cabbage and tear them into smaller pieces. 2) Fill the larger beaker with about 150 milliliters of distilled water. Place the torn pieces of red cabbage into the beaker.
3) Place the beaker on tripod Turn the heat up to medium or medium high. 4) Once the water starts to boil, turn down the heat so it boils gently. 5) If it looks like there's not enough water to cover the leaves, or too much of the water is boiling way, add a little more of the distilled water. (Perhaps another 50 mL) Keep it at a gentle boil for about 10 minutes, or until the water turns a purple color.Then turn off the heat and let it cool down. 6) Once the cabbage cools down, pour the cabbage extract liquid into another 250 ml beaker.
7) Place substance that you want test in different test tubes. Add red cabbage juice by eyedropper to each test tube to check the acidity and record result. Safety precaution: * Acid and base are corrosive, irritating to the skin and often release choking vapor. So avoid in contact with your skin, eye and skin protection should always be worn when using them.
* Transfer by dropper only small amounts at a time. Have alkali or acid on hand for neutralization in order to minimize the threat caused by accident spill of acid or base. * Neutralization reactions generate heat, so care must be taken if neutralizing. Solution| Color| Sodium hydroxide (NaOH)| Yellow| Hydrochloric acid (HCl)| Pink| White Vinegar| Light Pink| Water| Purple| Result: Substance| Acidic| Neutral| Basic| Hydrochloric acid (HCl) | | | | Sodium hydroxide (NaOH)| | | | White Vinegar | | | | Lemon Juice| | | | Baking soda (NaHCO3)| | | | Hair conditioner| | | | Shampoo| | | | Hand soap| | | | Cloudy Ammonia| | | |Dish washing detergent| | | | Water| | | | Discussion: * We used tab water instead of distilled water.
It may affect acidity of the cabbage juice that supposed to be neutral. Tab water contained some impurity. Such as sodium hypochlorite (NaClO), for disinfection reason. It gives slightly alkali state to the water.
Using distilled water allow us to avoid preceding problems. Conclusion: Acidity and alkalinity of household substance are successfully classified by the natural indicator extracted from red cabbage. Foods are basically acidic and detergent or cleaner are basically basic. Diagram:
