Question

Write the number of donor atoms present in EDTA, during formation of complex.

Answer 1

Step 1: Structure of EDTA.

EDTA stands for Ethylenediaminetetraacetic acid. Its formula is: \[ \text{H}_4\text{Y} \;=\; (HOOC-CH_2)_2N-CH_2-CH_2-N(CH_2COOH)_2 \]

Step 2: Possible donor atoms.

In the deprotonated form (\(Y^{4-}\)), EDTA has:

• Two nitrogen atoms (–NH– groups) with lone pairs
• Four oxygen atoms from carboxylate groups (–COO\(^-\))

Step 3: Total donor atoms.

Therefore, EDTA can coordinate to a metal ion through \[ 2 \;(\text{N}) + 4 \;(\text{O}) = 6 \;\;\text{donor atoms.} \]

Step 4: Conclusion.

EDTA acts as a hexadentate ligand (capable of binding through six donor atoms).

Final Answer:

Number of donor atoms in EDTA = \[ \boxed{6} \]