Which element is not present in Nessler's reagent ?
- A
Mercury
- B
Potassium
- C
Iodine
- D
Oxygen
MCQEasyJEE 2023Preparation of Common Compounds
JEE Chemistry 2023 Question with Solution
Answer
Correct answer:B
Step-by-step solution
Standard Method
Given: Nessler’s reagent is discussed.
Find: Which element is not present in Nessler’s reagent.
Nessler’s reagent is an alkaline solution of .
From the formula, the elements present are potassium, mercury, and iodine.
Therefore, oxygen is not present in the reagent itself. The solution states the correct option as B, but this conflicts with the chemical composition and the listed options. Based on the working, the defensible correct option is D.
Common mistakes
Confusing the stated option label with the chemical working. The formula clearly contains potassium, mercury, and iodine, so you must verify the composition instead of copying the mislabeled option.
Assuming oxygen is present because the reagent is an alkaline solution. The reagent composition is identified from its formula, not from the medium in which it is prepared.
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