QJEEM25Ch56db: JEE Main 2025 Chemistry - Class 12 JEEM25Ch56db Solution: Among the following cations, the number of cations which will…

Among the following cations, the number of cations which will give characteristic precipitate in their identification tests with $\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]$ is ________.

$\mathrm{Cu}^{2+}, \mathrm{Fe}^{3+}, \mathrm{Ba}^{2+}, \mathrm{Ca}^{2+}, \mathrm{NH}_4^{+}, \mathrm{Mg}^{2+}, \mathrm{Zn}^{2+}$