The compound \(K_2[HgI_4]\) is known to detect the ammonium ion, \(NH_4^+\). Here's a step-by-step explanation of how it works:
Understanding the Compound: The compound \(K_2[HgI_4]\) is potassium tetraiodomercurate(II). It is used in various chemical tests due to its ability to form insoluble complexes with certain ions.
Chemical Reaction: When ammonium ions are present in a solution, they react with the potassium tetraiodomercurate(II) to form a distinctive white precipitate. The reaction can be summarized as:
\(NH_4^+ + K_2[HgI_4] \rightarrow (NH_4)_2[HgI_4]\)
The formation of the white precipitate of ammonium tetraiodomercurate(II) indicates the presence of ammonium ions.
Ruling Out Other Ions: The other ions given in the options (Cl\(^-\), NO\(_2^-\), and NO\(_3^-\)) do not form such a precipitate with \(K_2[HgI_4]\). This specificity makes it a reliable test for \(NH_4^+\) ions.
Conclusion: The correct answer is \(NH_4^+\) because it is the only ion among the options that forms a characteristic precipitate with \(K_2[HgI_4]\).
Understanding this reaction is crucial for identifying ammonium ions in qualitative analysis in chemistry.
Which of the following statements are true?
A. Unlike Ga that has a very high melting point, Cs has a very low melting point.
B. On Pauling scale, the electronegativity values of N and C are not the same.
C. $Ar, K^{+}, Cl^{–}, Ca^{2+} and S^{2–}$ are all isoelectronic species.
D. The correct order of the first ionization enthalpies of Na, Mg, Al, and Si is Si $>$ Al $>$ Mg $>$ Na.
E. The atomic radius of Cs is greater than that of Li and Rb.
Choose the correct answer from the options given below: