chemistry PBL 2 NAME: Angel Lim Kah Xin CLASS: 4S4 TITLE: Report (Using Natural Ingredients as pH Indicators) TEACHER: Pn. Chan Yoke Bee
pH indicators exist as liquid dyes and dye-infused paper strips. They are added to various solutions to determine the pH values of those solutions. It changes colours under different ph condition. Whereas the liquid form of pH indicators is usually added directly to solutions, the paper form is dipped into solutions and then removed for comparison against a color/pH key. Only a small amount of indicator compound is needed to produce a visible color change. It is important because it allow us to visually determine how acidic or alkaline a solution is. pH indicators can be used in a variety of ways, including measuring the pH of farm soil, shampoos, fruit juices, and bodies of water. Many red, purple, and blue plants contain chemicals called anthocyanins, which are weak acids that dissolve in water and change color in response to changes in pH. Because of this, plants with anthocyanins like red cabbage and blueberries can easily be made into pH indicators. Report: Using NaturalIngredients as pH Indicators Introduction to pH indicators and their importance Explanation of how natural ingredients can be used as pH indicators
Red cabbage Lemon Vinegar Soft drink Water The materials needed was prepared. Red cabbage was cutted and boiled with some water to make pH indicator. The pH indicator solution was cooled down for 20 minutes. The plastic cup was added lemon juice. The pH indicator solution was poured to the plastic cup. Step 5 was repeated with replacing lemon juice by vinegar, soft drink, water, shampoo (+water), toothpaste(+water) and baking soda (+ water). The colour change was observed and recorded. Description of the experiment conducted, including materials used and procedures followed This experiment shows how to use natural ingredients as pH indicators. Materials: Procedure: 1. 2. 3. 4. 5. 6. 7. Shampoo (+water) Toothpaste(+water) Baking soda (+ water) Plastic cups
The colour of the indicator will change to red or pink if the solution is an acid and it will change to green or yellow if it is an alkali. It will remain purple or blue if the test solution is neutral. pH changes occur in substances necessary for human, plant, or animal survival. This is important to know because plants and animals survive only narrow pH changes. Soil pH testing is important because changes in pH value make it infertile. Testing the pH value of rainwater to check for the occurrence of acid rain (which occurs at pH < 5.6). When humans have acidity problems, it indicates a low pH value in our stomach. Tooth decay indicates a low pH value in the mouth. Results obtained from the experiment, including any observations or trends noticed Discussion of the significance of the results obtained, and their relevance to real-world applications By testing pH in daily life, we can determine: