What does EDTA titration detect?

EDTA is used to titrate many ions. For instance, EDTA has been used succesfully over the years for the determination of water hardness (a meassure of the total Ca2+ and Mg2+ ions in water). Water hardness is often conveniently determined by titration of total Ca2+ and Mg2+ ions with EDTA.

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What is the colour change in EDTA titration?

EDTA is short for ethylenediaminetetraacetic acid. A blue dye called Eriochrome Black T (ErioT) is used as the indicator. This blue dye also forms a complex with the calcium and magnesium ions, changing colour from blue to pink in the process.

How is EDTA concentration calculated?

Calculate the concentration of calcium ions in the hard water sample.

Calculate the average titre of EDTA: average titre = (8.76 + 8.80 + 8.78) ÷ 3 = 8.78 mL = 8.78 x 10-3 L.
Calculate the moles of EDTA in the average titre: moles(EDTA) = concentration (mol L-1) x volume (L) = 0.010 x 8.78 x 10-3 = 8.78 x 10-5 mol.

How do you find the total hardness of water by EDTA titration?

Hardness of water is determined by titrating with a standard solution of ethylene diamine tetra acetic acid (EDTA) which is a complexing agent. Since EDTA is insoluble in water, the disodium salt of EDTA is taken for this experiment. EDTA can form four or six coordination bonds with a metal ion.

What is titration analysis?

titration, process of chemical analysis in which the quantity of some constituent of a sample is determined by adding to the measured sample an exactly known quantity of another substance with which the desired constituent reacts in a definite, known proportion.

Why is pH 10 buffer used in EDTA titration?

pH 10 buffer is used in EDTA titration because in EDTA Y4- is predominant, and we want Y4- to react with the metal ions that are present in the titration solution. This can be achieved by using a pH 10 buffer.

How do you check the hardness of water in a lab?

Hardness is commonly measured by colorimetric titration with an EDTA solution. A titration involves adding indicator and then titrant solution in small increments to a water sample until the sample changes color. You can titrate a sample for total hardness using a burette or use a water hardness test kit.

What is a high water hardness level?

General guidelines for classification of waters are: 0 to 60 mg/L (milligrams per liter) as calcium carbonate is classified as soft; 61 to 120 mg/L as moderately hard; 121 to 180 mg/L as hard; and more than 180 mg/L as very hard.

How to write a lab report about titration?

The Establishment of a Chemical Equation Using the Method of Continuous Variation.

COMPLEXOMETRIC DETERMINATION OF WATER HARDNESS LAB. UNKNOWN SAMPLE#97 COMPLEXOMETRIC DETERMINATION OF WATER HARDNESS DR.

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Why is EDTA used for titration?

EDTA (aq)+NH3 buffer+EBT indicator+Ca++/Mg++= EDTA complex with Ca++/Mg++(either/or)

Ca++and/or Mg++complexes with EDTA,going from pink to blue in the presence of Erichrome Black-T and buffer,when no Mg++or Ca++remain uncomplexed.

So (18.25ml/50.00ml) x 0.00940M = 0.003431mole of EDTA

The Ca/Mg is usually reported as ppm CaCO3

What is the principle of EDTA titration?

Take 25ml of given sample in conical flask.

Now add 1ml of buffer solution.

Now in sample and buffer solution add 1ml of inhibitor as well.

Now add 2 drops of eriochrome black – T solution in the mixture which turns the color of the solution wine red.

Fill the burette with EDTA solution.

End point can be detected by color change from wine red to blue.

How to standardize EDTA?

Weigh accurately about 400 mg of Calcium Carbonate.

Previously dried at about 110°C for about 2 hours.

Transfer it in a cleaned and dried 500 ml conical flask and add about 10 ml of water with gentle stirring to form the slurry.

Dissolve the carbonate in 2 ml of dilute hydrochloric acid and shake well until it dissolves.