MAKING A WEATHER INDICATING FLOWER

The amount of moisture in the air, i.e. humidity, can be used as the basis for forecasting the weather. When the humidity is high, rain is likely, while a low humidity usually indicates a dry spell.
This project is based on the colour change produced in cobalt chloride by the moisture in air.

You Require
•     Cobalt chloride, about 20 gm
•     Blotting paper
•     Thread
•     One thin wooden stick about 3 mm thick and 15 cm long
•     Scissors
What To Do
•    Take a small sheet of blotting paper and cut it in the shape of a flower, as shown in figure.
•    With the help of cotton thread and a sewing needle, tie it with the thin wooden stick.
•    Now take about 20 gm of cobalt chloride from a chemicals supplier or from your laboratory and make a strong solution of it in water.   .
•    Dip the blotting paper flower in this solution, then put the flower in a warm place to dry.
•    Now, your weather-indicating flower is ready for use. tf the colour of the flower becomes pink on some day, it indicates a storm; if the colour becomes bluish-pink, it indicates rain; and if the colour becomes light blue, it indicates dry weather.
Note: You can also make a weather indicator by using a strip of blotting paper and soaking it in the solution of cobalt chloride in a similar way as described above.