Which of the following compounds forms white precipitate with $\mathrm{K} 4 \mathrm{Fe}(\mathrm{CN})_{6} ?$
- $\mathrm{Cu}^{2+}$
- $\mathrm{NH}_{4}^{+}$
- $\mathrm{Zn}^{2+}$
- $\mathrm{Ca}^{2+}$
Solution
$\mathrm{Zn}^{2+}+2 \mathrm{K}^{+}\left[\mathrm{Fe}(\mathrm{CN})_{6}ight]^{4-} ightarrow \mathrm{K}_{2} \mathrm{Ca}\left[\mathrm{Fe}(\mathrm{CN})_{6}ight] \downarrow($ white ppt. $)$ ^
Asked in: JEE-TOPICTESTS-CHEMISTRY