Prepare Nickel Dimethyl Glyoxime

 

Abstract

This experiment aims to synthesize nickel dimethyl glyoxime, a complex compound commonly used in analytical chemistry for the detection and determination of nickel ions.

Introduction

Nickel dimethyl glyoxime is a coordination compound formed by the reaction of nickel sulfate, dimethylglyoxime, and ammonium hydroxide. It is an insoluble red precipitate and is used as a qualitative test for the presence of nickel ions in solution due to its characteristic coloration.

Experiment Details

The experiment involves the following steps:

Procedure

1. Dissolve 5 g of nickel sulfate hexahydrate (\(NiSO_4 \cdot 6H_2O\)) in 50 mL of distilled water in a beaker.
2. Add excess dimethylglyoxime solution dropwise to the nickel sulfate solution while stirring continuously.
3. Continue stirring for 10-15 minutes to ensure complete precipitation.
4. Filter the precipitate using a filter paper and wash it with distilled water to remove any impurities.
5. Dry the precipitate in an oven at 100°C for 1 hour.
6. Weigh the dried precipitate to determine the yield.

Observations and Calculations

The reaction involved in the formation of nickel dimethyl glyoxime can be represented as:

\(NiSO_4 \cdot 6H_2O + 2(C_4H_7NO_2)_2C_2H_2(NOH) \rightarrow Ni(C_8H_14N_4O_4) + 6H_2O + H_2SO_4\)

Theoretical yield of nickel dimethyl glyoxime can be calculated using stoichiometry and molar masses of reactants and products.

Conclusion

In conclusion, nickel dimethyl glyoxime was successfully synthesized by the reaction of nickel sulfate and dimethylglyoxime. The precipitate obtained was characterized by its red coloration and insolubility in water. The yield of the product was determined to assess the efficiency of the synthesis process.

Precautions

• Handle chemicals with care, as they may be hazardous.
• Perform the experiment in a well-ventilated area to avoid inhalation of fumes.
• Use appropriate protective equipment such as gloves and goggles.
• Ensure proper disposal of waste chemicals according to safety guidelines.

Short Questions

1. What is the purpose of synthesizing nickel dimethyl glyoxime?
   Answer: Nickel dimethyl glyoxime is synthesized for qualitative and quantitative analysis of nickel ions in solution.
2. What is the color of nickel dimethyl glyoxime precipitate?
   Answer: The precipitate of nickel dimethyl glyoxime is red.
3. How is nickel dimethyl glyoxime used in analytical chemistry?
   Answer: It is used as a reagent for the detection and determination of nickel ions.
4. What are the reactants used in the synthesis of nickel dimethyl glyoxime?
   Answer: Nickel sulfate hexahydrate and dimethylglyoxime.
5. What is the chemical formula of nickel dimethyl glyoxime?
   Answer: Ni(C₈H₁₄N₄O₄)
6. What precautions should be taken during the synthesis of nickel dimethyl glyoxime?
   Answer: Handle chemicals with care, use appropriate protective equipment, and work in a well-ventilated area.
7. Why is dimethylglyoxime added dropwise to the nickel sulfate solution?
   Answer: To ensure complete precipitation and avoid excessive formation of impurities.
8. How is the yield of nickel dimethyl glyoxime determined?
   Answer: By weighing the dried precipitate obtained from the reaction.
9. What is the role of ammonium hydroxide in the synthesis reaction?
   Answer: It helps in the formation of the complex compound and controls the pH of the solution.
10. What is the theoretical yield of nickel dimethyl glyoxime?
    Answer: It can be calculated based on stoichiometry and molar masses of reactants and products.
11. What is the purpose of drying the precipitate in an oven?
    Answer: To remove moisture and obtain the dry product for accurate weighing.
12. What type of reaction is involved in the synthesis of nickel dimethyl glyoxime?
    Answer: Coordination complex formation reaction.
13. What are the properties of nickel dimethyl glyoxime?
    Answer: It is insoluble in water and forms a red precipitate.
14. How can the purity of the synthesized nickel dimethyl glyoxime be assessed?
    Answer: By conducting qualitative and quantitative analysis, and comparing with standard samples.
15. What are the potential hazards associated with the synthesis process?
    Answer: Exposure to toxic chemicals, inhalation of fumes, and risk of burns.
16. What are the applications of nickel dimethyl glyoxime?
    Answer: It is used in qualitative analysis of nickel ions and as a reagent in complexometric titrations.
17. How can the synthesis process be optimized to improve yield?
    Answer: By controlling reaction conditions such as temperature, pH, and stoichiometry of reactants.
18. What are the environmental considerations when performing this experiment?
    Answer: Proper disposal of waste chemicals and minimizing use of hazardous substances.
19. What are the alternative methods for synthesizing nickel dimethyl glyoxime?
    Answer: Using different metal salts or ligands, or employing microwave-assisted synthesis.
20. What are the limitations of using nickel dimethyl glyoxime as a qualitative test for nickel ions?
    Answer: Interference from other metal ions and low sensitivity in some cases.

Multiple Choice Questions

1. What is the color of nickel dimethyl glyoxime precipitate?
   a) Yellow
   b) Blue
   c) Red
   d) Green
   Answer: c) Red
2. What is the purpose of adding excess dimethylglyoxime solution to the nickel sulfate solution?
   a) To neutralize the solution
   b) To enhance the reaction rate
   c) To ensure complete precipitation
   d) To increase the solubility of the precipitate
   Answer: c) To ensure complete precipitation
3. What is the chemical formula of nickel dimethyl glyoxime?
   a) NiSO₄
   b) Ni(C₄H₇NO₂)₂
   c) Ni(C₈H₁₄N₄O₄)
   d) Ni(C₂H₈N₂)₂
   Answer: c) Ni(C₈H₁₄N₄O₄)
4. What precaution should be taken during the synthesis of nickel dimethyl glyoxime?
   a) Avoid using gloves
   b) Perform the experiment in a poorly ventilated area
   c) Handle chemicals with care
   d) Disregard safety guidelines
   Answer: c) Handle chemicals with care
5. How is the yield of nickel dimethyl glyoxime determined?
   a) By measuring the volume of the precipitate
   b) By weighing the dried precipitate
   c) By titration
   d) By conducting spectroscopic analysis
   Answer: b) By weighing the dried precipitate