Prepare your own indicator
i) Crush beetroot in a mortar.
ii) Add sufficient water to obtain the extract.
iii) Filter the extract by the procedure learnt by you in earlier classes.
iv) Collect the filtrate to test the substances you may have tasted earlier.
v) Arrange four test tubes in a test tube stand and label them as A,B,C and D. Pour 2 mL each of lemon juice solution, soda-water, vinegar and baking soda solution in them respectively.
vi) Put 2-3 drops of the beetroot extract in each test tube and note the colour change if any. Write your observation in a Table.
vii) You can prepare indicators by using other natural materials like extracts of red cabbage leaves, coloured petals of some flowers such as Petunia, Hydrangea and Geranium.