Question

What is the effective atomic number of Zn in \([Zn(NH_3)_4]SO_4\)? (Atomic number of Zn = 30)

• A. 30
• B. 27
• C. 36
• D. 28

Hint:

To find the effective atomic number (EAN), sum the electrons contributed by the central metal ion and the ligands.

Answer 1

The Correct Option is C

Step 1: Understanding the concept of effective atomic number.
The effective atomic number (EAN) is the total number of electrons surrounding the metal ion. In \([Zn(NH_3)_4]SO_4\), the Zn\(^{2+}\) ion is surrounded by four NH\(_3\) molecules. Each NH\(_3\) donates 2 electrons, and the Zn\(^{2+}\) ion contributes 2 electrons. The total effective atomic number is: \[ EAN = 30 (\text{Zn electrons}) + 4 \times 2 (\text{electrons from NH}_3) = 36 \]
Step 2: Conclusion.
The effective atomic number of Zn is 36.