Question

A reagent which gives brilliant red precipitate with Nickel ions in basic medium is

• A. sodium nitroprusside
• B. neutral FeCl$_3$
• C. meta-dinitrobenzene
• D. dimethyl glyoxime

Answer 1

The Correct Option is D

To determine which reagent gives a brilliant red precipitate with Nickel ions in a basic medium, let's analyze each option:

1. Sodium nitroprusside: This reagent is commonly used as a detection test for sulfide ions. It does not react with Nickel ions to give a red precipitate, especially not in a basic medium.
2. Neutral FeCl₃: Ferric chloride is generally used as a reagent to test for phenols and is not known to react with nickel to form a brilliant red precipitate. 
3. Meta-dinitrobenzene: This is an organic compound which does not participate in reactions with Nickel ions to give a color precipitate in any medium.
4. Dimethyl glyoxime: This reagent is known to form a complex with Nickel ions that produces a distinctive red precipitate. The reaction is as follows:

When dimethyl glyoxime is added to a solution containing Nickel ions (\(Ni^{2+}\)) in a basic medium (usually achieved by adding ammonia or another base), a red precipitate of nickel(II) dimethylglyoxime complex is formed:

\(Ni^{2+} + 2(C_4H_8N_2O_2) + 2OH^- \rightarrow Ni(C_4H_7N_2O_2)_2 \, (red \, precipitate) + 2H_2O\)

Thus, the correct answer is dimethyl glyoxime because it forms a red precipitate with Nickel ions in a basic medium.

In conclusion, the reagent that gives a brilliant red precipitate with Nickel ions in a basic medium is dimethyl glyoxime.

Answer 2

The reagent that gives a brilliant red precipitate with Nickel ions (\( \text{Ni}^{2+} \)) in a basic medium is dimethyl glyoxime (dmg). When \( \text{Ni}^{2+} \) reacts with dimethyl glyoxime, it forms a complex that produces a bright red precipitate. The reaction is as follows:  
\(\text{Ni}^{2+} + \text{dmg} \rightarrow [\text{Ni}(\text{dmg})_2] \, \, (\text{Rosy red/Bright Red precipitate})\)

Thus, the correct answer is dimethyl glyoxime.

The Correct Answer is: dimethyl glyoxime