Question

What is the number of nitrogen atoms and −COO⁻ groups respectively present in EDTA?

Options

• 3, 2

• 2, 2

• 2, 4

• 4, 4

Answer 1

2, 4

Explanation:

\[\begin{array}{cc}
\phantom{............}\ce{HOOC - CH2}\phantom{......................}\ce{CH2 - COOH}\phantom{}\\
\phantom{............}\backslash\phantom{....................}/\phantom{}\\
\phantom{............}\ce{\overset{\bullet\bullet}{N} - CH2 - CH2 - \overset{\bullet\bullet}{N}}\\
\phantom{............}/\phantom{....................}\backslash\phantom{}\\
\phantom{............}\ce{HOOC - CH2}\phantom{......................}\ce{CH2 - COOH}\phantom{}\\
\phantom{............}\ce{\underset{(EDTA)}{Ethylenediamminetetraacetic acid}}
\end{array}\]

Number of nitrogen atoms = 2

Number of −COO⁻ groups = 4