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How does EDTA complex with Ca2+ and Mg2+?

by Rhyley Bryan

How does EDTA complex with Ca2+ and Mg2+?

The combined concentration of calcium and magnesium ions is considered to be the measure of water hardness. The method uses a very large molecule called EDTA which forms a complex with calcium and magnesium ions. The indicator is added and remains blue as all the Ca2+ and Mg2+ ions present are complexed with the EDTA.

How many moles of EDTA react with Ca2+?

One mole of Ca2+ ions will react with one mole of EDTA ions.

How do you calculate EDTA titration?

One way to calculate the result is shown:

  1. Mass of. Calcium. (mg) =Volume. EDTA (L)× Molarity. EDTA (mol / L) × 1 mol Calcium. 1 mol EDTA. ×
  2. Percentage. Magnesium. (% w / w) = Volume. EDTA (L)× Molarity. EDTA (mol / L) × 1 mol Magnesium.
  3. Calcium. Carbonate. (mg / L) =Volume. EDTA (L)× Molarity. EDTA (mol / L) × 1 mol CaCO3. 1 mol EDTA. ×

How is hardness of water determined by EDTA titration?

Calcium Analysis by EDTA Titration One of the factors that establish the quality of a water supply is its degree of hardness. The hardness of water is defined in terms of its content of calcium and magnesium ions. Since an analysis does not distinguish between Ca2+ and Mg2+, and since most hardness is caused by

What happens when calcium ions are titrated with EDTA?

As a result, when the calcium ion–PR complex is titrated with EDTA the Ca2+ ions react to form a stronger complex with the EDTA. For the titration, the indicator is added to the sample solution containing the calcium ions and forms the pink/red calcium ion-indicator complex (Ca-PR).

How are EDTA and Calmagite used in calcium analysis?

In the Calcium analysis by titration with EDTA, the EDTA added combines quantitatively with the to form the complex Ca(EDTA). Calmagite and 2 methyl red indicators were used for this analysis given that EDTA and are both colorless.

How are magnesium and calcium determined by titration?

A comparison was made of four methods for the determination of magnesium by titration with EDTA (disodiumdihydrogen-ethylenediaminetetraacetate).