Acids and Alkali Alex Cheong 1P404

Contents Introduction Objective Hypothesis Materials Procedure Results Conclusion

Introduction Acids are sour and form hydrogen gas when they react with metals Citric acid, acetic acid Alkali are bitter and slippery. Most are water soluble Sodium hydroxide, magnesium hydroxide pH scale is a way to measure the strength of an acidic or alkaline solution Acids have a pH of 0-7, while alkali have a pH of 7-14 Water’s pH level is 7, and is a neutral solution

Objective Easily identify acids and alkali solutions in our everyday substances using the juice of the red cabbage

Hypothesis The juice of the red cabbage can be used to identify acids and alkali

Materials Red cabbage Toilet bleach Father Lemon juice Baking soda Salt Vinegar Sugar

Procedure Peel some red cabbage leaves Boil the cabbage leaves for 15 minutes Transfer the liquid into a bottle Pour some into the test tube Add one of the everyday substances into the test tube Observe the colour of the indicator Write down the results in a table

Results Substance Added Colour After Adding Vinegar Reddish Lemon Pinkish Baking Soda Green

Results (continued) Substance Added Colour After Adding Toilet Bleach Yellow Sugar No Difference Salt

Conclusions Red cabbage juice can be used as a indicator solution to identify acids and alkali. The red cabbage has a pigment called anthocyanin in it’s juice which colour depends on the pH of the solution If the substance is a … acid, then the solution will turn pink to red alkali, then the solution will turn blue, green to yellow From the results, we can see that toilet bleach is a strong alkaline.