Steps and procedures There are the steps to make purple cabbage indicator: 1. The purple cabbage was chopped into small pieces. 2.The chopped purple cabbage was put into saucepan and cover with 500ml water. 3.The chopped purple cabbage was boiled for thirty minutes in low flames. 4. The boiled purple cabbage kept until cool down. 5.The boiled purple cabbage water was strained into a beaker. The dark purple liquid in the beaker is the PH indicator liquid. 6.The cotton buds dipped into the purple cabbage liquid for 2 hours. 7. The dipped cotton buds kept dried under the sunlight for 5 hours. Now, the ‘pH Cotton Swabber’ ready for test. Step to test the pH indicator : 1.50 ml of household chemicals were poured into labelled beakers. 2. The ‘pH Cotton Swabber’ dipped into the household chemicals. 3.The colour changes of ‘pH Cotton Swabber’ was recorded. 4.Steps 2 and 3 repeated with different household chemicals. 8.The PH indicator chart was referred to check the properties of household chemical whether acidic, neutral or alkaline. CONCLUSION Purple cabbage used as an indicator to determine whether a substances are acidic,alkaline or neutral.The purple cabbage pH indicator turns red with acidic substances,green with alkaline substances and no changes colour and remain purple with neutral substances. The pH value of acidic substances is lower than 7. The pH value of alkaline substances is more than 7. The pH value of neutral substances is 7. Litmus paper is very expensive and hard to get. So, that is why we came out with this innovation of using red cabbage as PH indicator as it can be easily get in grocery store and cheap.
Purple cabbage PH indicator
‘Purple cabbage PH indicator’. We tested some natural indicators such as purple cabbage, beetroot, turmeric, ginger, carrot, rose petal, onion, mangosteen, dragon fruit and hibiscus petal for three times and we found out that purple cabbage was the best indicator. Because purple cabbage has a water based pigment in its dye called anthocyanin. This fancy pigment can be used as a pH indicator. Purple cabbage considered to be an indicator because it shows us something about the chemical composition of other substances. It also contains a natural PH indicator that changes colours according to the acidity of the solution. Purple cabbage indicators are easy to make, exhibit a wide range of colours, and can be used to make our own pH indicator ‘pH cotton swabber’.