Why are substances containing copper ions blue?

When water is added to the copper chloride solution, the concentration of chloride ions in the solution becomes smaller, and the hydrated copper ions increase relatively, and the solution mainly presents the color of hydrated copper ions (blue). So the copper chloride dilute solution we see is generally blue.

Copper ions are obtained by the copper atom losing the outermost two electrons, the apparent positive 2valence, written as Cu2+, showing the schematic diagram of the structure of the blue copper ion Generally, the copper ion Cu2+ actually exists in the form of hydrated ions [Cu(H2O)4]2+ in aqueous solution, and the hydrated copper ions are blue, so most of our common copper salt solutions are blue.

Because copper is a crystal, and copper ions are already ions, the state is different.

If you are a high school student, it is recommended that you do not delve into it. There are a lot of things in high school that can't be explained, and if you really know a lot, you probably won't get it right.

You just need to remember that the copper ion aqueous solution is blue, but not all substances containing copper ions are blue, why is it blue, you can remember some common things now, copper sulfate solution is blue, copper sulfate pentahydrate is blue, etc., these common substances in the college entrance examination can be.

Not necessarily, like copper hydroxide is blue, hydrated copper sulfate is also blue, but anhydrous copper sulfate, basic copper carbonate, copper oxide and so on are not blue.

The 3D electron transition in copper ions is to absorb orange light, and copper ions show orange complementary colors, so they are blue.

If we add water to the copper chloride solution, the concentration of chloride ions in the solution becomes smaller, and the hydrated copper ions increase relatively, and the solution mainly shows the color of hydrated copper ions (blue). So the copper chloride dilute solution we see is generally blue.

In the reaction of copper nitrate, the solution obtained by the reaction of dilute nitric acid with copper is blue, while the solution obtained by the reaction of concentrated nitric acid with copper is green. This is because when concentrated nitric acid reacts with copper, a large amount of nitrogen dioxide gas is produced, and nitrogen dioxide dissolves in solution and appears yellow, and the yellow color of nitrogen dioxide is mixed with the blue of hydrated copper ions to produce the green we see.

The main function of copper ions

Generate copper. Copper ions can be generated by reduction reaction, copper can be generated by oxidation reaction, copper ions can also be obtained by dissolving copper salts in water or melting, and copper ions can be combined with hydroxide ions to form water-insoluble Cu(OH)2 blue precipitates, which is also one of the methods to test copper ions. Copper ions are present in an alkaline solution to form a precipitate.

Antivirus. Copper ions can be used for anti-virus, and copper ions can be added appropriately in swimming pools, so swimming pool water is usually blue.

Because the peripheral electron configuration of the copper ion is 3d9, there are four empty orbitals: 4s and there are 2 lone electron pairs in the sum, and when the complex is formed, only one pair of lone electron pairs forms a coordination bond, so the coordination number of the copper ion is 4.

Copper ions are obtained by the copper atom losing the outermost two electrons, the apparent positive 2 valence, written as Cu2+, usually blue, copper ions Cu2+ in the aqueous solution are actually in the form of hydrated ions [Cu(H2O)4]2+, hydrated copper ions are blue, so most of our common copper salt solutions are blue.

1. Copper ions --- blue.

2. Ferrous ions --- light green.

3. Iron ion -- light purple (generally brownish-yellow in solution).

4. Manganese ions--- light pink.

5. Cobalt ions --- pink.

6. Nickel ions --- green.

7. Chromium ion - blue-green.

8. Chromium ion -- green.

9. Cadmium ion - blue-green.

10. Gold ions--- golden yellow.

Color is determined by the electromagnetic waves emitted or reflected by objects of different wavelengths, which is the perception of human vision, and some ions show different colors, which are determined by their intrinsic chemical properties.

The color of copper ions is blue-green. This is due to the absorption and reflection of light in the chain of Hezhi in the substance. Copper ions absorb red and yellow light, while reflecting blue and green light.

Therefore, when light passes through the field or reflects to copper ions, the color seen by the human eye is blue-green.

Hello. 1。The colors of the copper-based compounds are as follows.

Note: I am referring to solids, not the color of these solids dissolved in water or other solutions, because some substances after dissolution have greater solubility and dissolve into two or more ions, and those ions are combined with water molecules or solvent molecules to form a matching example, each combined ion has different refractive properties and absorbance, so the color is related to the ion concentration, which is difficult to judge. In fact, the essence of color development is that the substance absorbs a certain wavelength of light in the white light, causing the transition of electrons, and showing which school of the complementary colors of the wavelength of light).

Elemental: CU purplish-red or dark red.

Copper compounds: flame green; cuf red; CuCl white ; cubr yellow ; cui brown yellow ; Cucn white ; Cu2o dark red; Cu2S Black; cuf2 white; CuCl2 brownish-yellow (solution yellow-green); cubr2 brown; Cu(CN)2 brownish-yellow; cuo black ; cus black ; cuso4 colorless; CuSO4 5H2O Blue; Cu(OH)2 light blue ; Cu(bo2)2 blue ; Cu(OH)2 CuCO3 dark green; [Cu(H2O)4]2+Blue; [Cu(OH)4]2-blue-violet; [cu(NH3)4]2+ navy; [CuCl4]2-yellow; [cu(en)2]2 + dark blue-violet; Cu2[Fe(CN)6] brown-red; Alkyne copper red

2。In general, the formation of insoluble copper salts is formed by the reaction of copper ions and corresponding anions, such as Cuf, CuCl, CuSO4; In addition, there are also elemental copper that directly reacts with substances, such as Cu2S and CuCl2; There are also complexes formed in the solution (if necessary, the amount of related substances should be controlled), such as [Cu(OH)4]2-, [Cu(NH3)4]2+

Hope these help you!