Element not present in Nessler’s reagent is
- K
- Hg
- N
- I
The Correct Option is C
Approach Solution - 1
The correct option is (C): N
Nessler’s Reagent\(\rightarrow K_2[HgI_4]\)
Approach Solution -2
Nessler's reagent is a chemical reagent used for detecting the presence of ammonia (NH3) or ammonium ions (NH4+) in a solution. It is made by mixing potassium iodide (KI) and mercuric chloride (HgCl2) in a basic solution.
Therefore, the correct answer is (C) N.
Answer. C
Approach Solution -3
Nessler's Reagent Composition
Nessler's reagent is an alkaline solution of potassium tetraiodomercurate(II), \( \text{K}_2[\text{HgI}_4] \). It is prepared by dissolving mercuric iodide (\( \text{HgI}_2 \)) in an aqueous solution of potassium iodide (\( \text{KI} \)) and then adding potassium hydroxide (\( \text{KOH} \)).
The elements present in Nessler's reagent are potassium (K), mercury (Hg), and iodine (I).
Conclusion:
Nitrogen (N) is not part of the chemical formula of Nessler's reagent.
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Concepts Used:
D and F Block Elements
The d-block elements are placed in groups 3-12 and F-block elements with 4f and 5f orbital filled progressively. The general electronic configuration of d block elements and f- block elements are (n-1) d 1-10 ns 1-2 and (n-2) f 1-14 (n-1) d1 ns2 respectively. They are commonly known as transition elements because they exhibit multiple oxidation states because of the d-d transition which is possible by the availability of vacant d orbitals in these elements.
They have variable Oxidation States as well as are good catalysts because they provide a large surface area for the absorption of reaction. They show variable oxidation states to form intermediate with reactants easily. They are mostly lanthanoids and show lanthanoid contraction. Since differentiating electrons enter in an anti-penultimate f subshell. Therefore, these elements are also called inner transition elements.
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