Estimation of total Hardness of water.

 1QWhat is the full form of EDTA.

Ethylenediamine Tetraacetic acid.

2Q EBT

Eriochrome Black T 

blue black color

forms unstable compounds with calcium and magnesium ionas in Hardwater at a ph of  9 - 10.

3QColor change

red to blue

4QHow do u calculate total hardness.

molarity * 10^5 

5QUnits of Hardness.

mg/l

6QDefine Titrate and Titrant.

Titrate: The solution which contains the substance to be estimated(Amount of hardness)

Titrant:The solution of known strength(EDTA)

7QWhy EBT is used instead of other indicators.

Eriochrome black T is used as an indicator for complexometric titrations because it forms a colored complex in its protonated form with calcium, magnesium, and other metal ions.

8QDefine the term Titration and indicator.

 The process of finding the volume of the solution required to react completely with a definite volume of other solution.

Indicator:

The reagent which indicates end point on equivalence point.

9Q What is a complexometric titration?

The titration involving formation of stable complexes between the metal and reagent.

metal - central atom

reagent - Ligand

10QWhat is Buffer solution?

Used to maintain the ph of a solution even when small amount of acid or base  is added.

Two types:

Acid: CH3COOH + CH3COONa

Basic : NH4OH + NH4Cl

11Q Why do we use buffer here.

EBT shows colour change when ph is 10.5 hence it is used to maintain the ph value.

12QWhat complexing reagent is used in this experiment.

EDTA

13QDefine Hardness of water.

The property pf water which restricts the formation of lather

14Q Difference between temporary and Permanent Hardness.