Question

Suggest a test to find the hardness of water and explain its procedure

Answer 1

Colorimeter can be used too measure the hardness of water. In a colorimeter when white light passes through the optical filter which transmits only one particular colour or band of wavelenghts of light to the photodetector, where it is measured. The measurement of the amount of coloured light transmitted by a coloured sample is the difference in the amount of coloured light transmitted by the sample i.e blank and that by a coloured sample. The amount of coloured light absorbed is directly proportional to the concentration. In this way the colorimeter is used to measure the hardness.