Obtaining of copper sulfate (II)

CuSO₄ - white crystalline powder, soluble in water. In the interaction with moist air or with water copper sulphate forms a crystalline (pentahydrate copper sulphate (II)), more commonly known as copper sulfate CuSO₄ • 5H₂O. Therefore, upon receipt of the hydroxide actually involved is not pure copper sulfate and its hydrated. Add to this solution an alkali (for example NaOH), and watch the reactions:

CuSO₄ + 5H₂O + 2NaOH = Na₂SO₄ + Cu(OH)co₂↓+5 H₂O.

When you add the proportionate amounts of reagent solution becomes colorless, and the copper hydroxide is precipitated in the form of a blue precipitate. Further, this solution may participate in the qualitative reactions on proteins.
Getting from copper nitrate (II)

Cu(NO₃)co₂ is a colourless crystalline substance. Enters into exchange reaction with strong bases. To carry out the reaction of obtaining the hydroxide salt can be added to the NaOH solution, colorless crystals of nitrate of copper (II). As a result, you will get a colorless solution of sodium nitrate and a precipitate of copper hydroxide (II) blue colour:

Cu(NO₃)co₂ + 2NaOH = Cu(OH)co₂↓ + 2NaNO₃.
Obtaining of copper chloride (II)

CuCl₂ - under normal conditions is a yellow powder or yellow-brown color. It is soluble in water. Pour in the vial of copper chloride and add an equivalent amount of alkali. Yellow crystals disappear and formed a blue precipitate. When you need to distinguish the substance from the solution, the precipitate filter and dry. Do not use vysokoenergeticheskie types of drying, because at temperature close to 100°C, Cu(OH)co₂ decomposes into copper oxide (II) and water:

CuCl₂ + 2NaOH = 2NaCl + Cu(OH)co₂↓.
Receiving from the acetate of copper (II)

(CH₃COO)₂Cu - substance, dark green color, soluble in water. When dissolved the solution becomes blue color. The calculated amount of alkali added to the solution of acetate of copper (II) and observe the formation of hydroxide (amorphous blue precipitate):

(CH₃COO)₂Cu + 2NaOH = Cu(OH)co₂↓+ CH₃COONa.

Since solutions of salts of copper (II) painted in blue or light blue color, the reaction is discoloration of the solution with subsequent precipitation of colored precipitate look very impressive.