Table of Contents
- 1 Why H2SO3 is used in estimation of copper as CuSCN?
- 2 Which reagent can be used to estimate nickel in steel by gravimetry?
- 3 Why is HCL added in gravimetric analysis?
- 4 Why NI DMG complex is Coloured?
- 5 What is the gravimetric estimation of nickel?
- 6 How do you determine the amount of copper in a solution?
Why H2SO3 is used in estimation of copper as CuSCN?
Copper will be precipitated as CuSCN (solubility product Kso=12.7). The presence of a reducing agent, for instance H2SO3 or NH4HSO3, to reduce Cu(II) to Cu(I). A slight excess of NH4SCN. A large excess increases the solubility of the copper thiocyanate due to formation of a complex.
Why is ammonia solution added during the gravimetric analysis of nickel?
The Gravimetric Estimation of Nickel: The reaction is performed in a solution buffered by either an ammonia or citrate buffer to prevent the pH of the solution from falling below 5.
Why basic medium is required in the gravimetric analysis of nickel using DMG as precipitating agent?
An alcoholic solution of dimethyglyoxime (DMG) is used as the precipitating reagent during the experiment because DMG is only slightly soluble in water (0.063 g in 100 mL at 25°C). It is therefore crucial to avoid the addition of too large an excess of the reagent because it may crystallize out with the chelate.
Which reagent can be used to estimate nickel in steel by gravimetry?
The Gravimetric Estimation of Nickel: The nickel is precipitated as nickel dimethyl glyoxime by adding alcoholic solution of dimethyl glyoxime C4H6(NOH)2 and then adding a slight excess of aqueous ammonia solution.
Why is copper thiocyanate white?
Copper(I) thiocyanate (or cuprous thiocyanate) is a coordination polymer with formula CuSCN. It is an air-stable, white solid used as a precursor for the preparation of other thiocyanate salts….Copper(I) thiocyanate.
| Names | |
|---|---|
| Molar mass | 121.628 g/mol |
| Appearance | white powder |
| Density | 2.88 g/cm3 |
| Melting point | 1,084 °C (1,983 °F; 1,357 K) |
What is physical gravimetry?
Physical gravimetry is the most common type used in environmental engineering. It involves the physical separation and classification of matter in environmental samples based on volatility and particle size (e.g., total suspended solids).
Why is HCL added in gravimetric analysis?
In the gravimetric method for determination of sulphate content of water samples or other sulphate materials you have to use hydrochloric acid with the barium chloride to completely precipitate the sulphate as barium sulphate.
What is the Colour of copper ammonia complex?
This complex ion imparts a characteristic pale blue color to the solution.
Why NI DMG complex is made alkaline?
The presence of iron in the solution interferes with the determination as the ferrous ions also form a red coloured complex with dimethylglyoxime. Therefore, the complex formation is carried out in alkaline solutions.
Why NI DMG complex is Coloured?
Nickel bis(dimethylglyoximate) is the coordination complex with the formula Ni[ONC(CH3)C(CH3)NOH]2. The compound is a bright red solid. It achieved prominence for its use in the qualitative analysis of nickel….Nickel bis(dimethylglyoximate)
| Names | |
|---|---|
| Appearance | red solid |
| Density | 1.698 g/cm3 |
| Hazards | |
| GHS pictograms |
Why do we use DMG?
Dimethylglyoxime (DMG) is an analytical reagent used to precipitate Ni from its aqueous solution. The process is very efficient for Ni recovery in terms of selectivity and completeness but hardly adopted industrially. The reason is attributed to the loss of the reagent when calcined.
Is copper a sulfate?
Copper sulfate is an inorganic compound that combines sulfur with copper. It can kill bacteria, algae, roots, plants, snails, and fungi. Copper is an essential mineral. It can be found in the environment, foods, and water.
What is the gravimetric estimation of nickel?
The Gravimetric Estimation of Nickel: The nickel is precipitated as nickel dimethyl glyoxime by adding alcoholic solution of dimethyl glyoxime C 4 H 6 (NOH) 2 and then adding a slight excess of aqueous ammonia solution. When the pH is buffered in the range of 5 to 9, the formation of the red chelate occurs quantitatively in a solution.
How can I calculate the amount of copper(I) thiocyanate in a gravimetric estimation?
This can be achieved by precipitating copper as copper (I)thiocyanate and massing the precipitated copper (I)thiocyanate, hence this is a gravimetric estimation. 2CuSO4 + 2NH4CNS + 2H2O + SO2 => 2CuCNS + (NH4) 2SO4 + H2SO4
What is the precipitate for nickel dimethyl glyoxime?
The nickel is precipitated as nickel dimethyl glyoxime by adding alcoholic solution of dimethyl glyoxime C 4 H 6 (NOH) 2 and then adding a slight excess of aqueous ammonia solution. When the pH is buffered in the range of 5 to 9, the formation of the red chelate occurs quantitatively in a solution.
How do you determine the amount of copper in a solution?
Determination of the amount of copper in a solution of Copper (II)sulphate. This can be achieved by precipitating copper as copper (I)thiocyanate and massing the precipitated copper (I)thiocyanate, hence this is a gravimetric estimation.