MCQ
Which of the following is a chocolate brown complex
- A$K_3[Cu(CN)_4]$
- B$[Cu(NH_3)_4]SO_4$
- ✓$Cu_2[Fe(CN)_6]$
- D$Na_3[Ag(S_2O_3)_2]$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Reason : Fluorine has $2s^2\,2p^5$ configuration.

