Experiment 1

HARDNESS OF WATER-

Webpage- https://byjus.com/jee/hardness-of-water-types-and-removal/

Water can be classified as hard water and soft water.

• Soft water: It lathers with soap. Water which is obtained from the rains is soft water. This water is suitable for household purposes for example laundry and cleaning.
• Hard water: It is known as hard water because of the presence of salts of calcium and magnesium. Hard water does not lather with soap but instead forms a precipitate.

The hardness of water can be classified into two types:

• Temporary Hardness: Presence of bicarbonates of calcium and magnesium caused temporary hardness. Removal method of temporaray hardness-

1. Boiling
2. Clark’s method

• Permanent Hardness: Presence of chlorides and sulphates of calcium and magnesium caused permanent hardness. Removal method of permanent hardness-

1. Permutit method
2. Calgon’s method
3. Ion exchange resin method

Quantitative Chemical Analysis:-Deals with the determination of the amount or percentage of one or more constituents of a sample.

Qualitative chemical analysis:- Deals with the identification of elements or grouping of elements present in a sample.

Volumetric analysis, any method of quantitative chemical analysis in which the amount of a substance is determined by measuring the volume that it occupies or, in broader usage, the volume of a second substance that combines with the first in known proportions, more correctly called titrimetric analysis.

Complexometric titration (sometimes chelatometry) is a form of volumetric analysis in which the formation of a colored complex is used to indicate the end point of a titration.Complexometric titrations are particularly useful for the determination of a mixture of different metal ions in solution.

The endpoint of the titration is the point at which the colour changes**.**

EDTA:Ethylene Diamine Tertraacetic Acid

EBT:Eriochrome Black T is a complexometric indicator that is used in complexometric titrations, e.g. in the water hardness determination process. It is an azo dye.