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EDTA (ethylenediaminetetraacetic acid) is the most widely used metal chelator in

ID: 1089519 • Letter: E

Question

EDTA (ethylenediaminetetraacetic acid) is the most widely used metal chelator in analytical chemistry, which forms strong 1:1 complexes with most metal ions. Water hardness can be determined by titrating Ca2+, Mg2+ and other metal ions with EDTA. During the titration, ammonium-ammonium chloride buffer is often used.

Which of the following descriptions about the function of ammonium-ammonium chloride is/are correct?

A) To form complex with Ca2+ and Mg2+ (Correct or incorrect)

B) To act as a masking agent (Correct or Incorrect)

C)To minimize the affect of other metal ions (Correct or incorrect)

D) To be used as a metal ion indicator (Correct or incorrect)

Explanation / Answer

Solution:

correct not correct To be used as a metal ion indicator .

Like Acid-Base indicators that were simply another acid or base, that had a color change between forms, Metal Ion indicators are metal complexing agents that have one when it binds a metal ion but it may have several different colors when it is not bound to the metal.