Copper Sulfate Formula – Structure, Properties, Uses, Sample Questions

Bluestone or Blue Vitriol are two names for copper sulphate. Because it is an inorganic salt that we use for dyeing, it is an excellent dyeing agent. Similarly, it functions as a catalyst in a few organic processes. It is mostly used as a fungicide to treat diseases of fruits and vegetables.

Copper Sulfate Formula 

Copper sulphate is a chemical substance that can refer to as either cuprous sulphate (Cu₂SO₄) or cupric sulphate (CuSO₄). The latter, however, is the preferred chemical denoted by the term copper sulphate. CuSO₄ is known scientifically as copper(II) sulphate, but it is commonly known as blue vitriol, Roman vitriol, copper vitriol, and bluestone.

Copper sulphate pentahydrate, with the chemical formula CuSO₄.5H₂O, is the most prevalent type. The brilliant blue colour of this shape distinguishes it. It should be noted, however, that the anhydrous form of this salt is a white powder. CuSO₄ is made up of an ionic connection between the copper cation (Cu²⁺) and the sulphate anion (SO₄^2-).

Manufacturing of Copper Sulphate

Virgin copper was utilised as a starting raw material in the production of copper sulphate. One of the most important sources of production is non-ferrous scrap. It is purified before being thrown into the water like molten metal. The shot is made up of rough spherical porous particles around the size of marbles. The shots are then dissolved in a dilute sulfuric acid solution. It is carried out in the presence of air in order to generate hot saturated liquor.

In order to compensate for the necessities, the created liquor is allowed to cool. If we want classic huge crystals of copper sulphate, we let the fluid cool slowly in large cooling vats. The lead strips in the vats provide a surface on which the crystals can grow. The cooling process is speed up by using water-cooled vessels if the desired product is granular (snow) crystal copper sulphate.

Properties of CuSO₄

Physical Properties

1. The anhydrous and pentahydrate forms of copper sulphate have molar masses of 159.609 and 249.685 grams per mole, respectively.
2. Anhydrous CuSO₄ appears grey-white and powdery, whereas pentahydrate appears vivid blue.
3. The densities of the anhydrous and pentahydrate forms are 3.6 g/cm³ and 2.286 g/cm³, respectively.
4. Copper sulphates, both hydrated and anhydrous, decompose when heated, hence their boiling points aren’t exact.
5. CuSO₄.5H₂O crystals contain orthorhombic crystal structures, whereas anhydrous CuSO₄ crystals have triclinic structures.

Chemical Properties

• Copper ions in copper sulphate react with chloride ions in concentrated hydrochloric acid, resulting in the creation of tetrachlorocuprate (II). The chemical reaction is given by-

Cu²⁺ + 4Cl^– -> CuCl₄^2-

• CuSO₄ undergoes a breakdown reaction when heated to 650ºC, yielding cupric oxide (CuO) and SO₃ (sulfur trioxide).
• Copper sulphate is very soluble in water, with solubility values of 1.055 molal at 10ºC and 1.502 molal at 30ºC.

Uses of Copper Sulfate

1. Because of its capacity to kill a variety of fungus, the pentahydrate of this chemical, CuSO₄.5H₂O, is employed as a fungicide.
2. Copper sulphate is used in Benedict’s solution as well as Fehling’s solution, which is utilised in sugar reduction testing.
3. It is also used to diagnose disorders such as anaemia by testing blood samples.
4. It is also used as a dye fixative in the vegetable dyeing process.
5. Copper sulphate solutions in water can be utilised as resistive element liquid resistors.
6. It can also be used as a decorative material because it can provide colour to cement, ceramics, and other metals.
7. Copper sulphate is also added to bookbinding glues to keep insects away from the printed paper.

Industrial Applications

It also used the copper plating method. The chemical has also been demonstrated to be beneficial to the mining industry. It acts as an activator in the concentration of lead, gold, and cobalt ores via froth flotation. Copper sulphate is also being used more widely in other industries, such as printing. It’s used as an electrolyte in the production of electrotypes and as an etching agent in print engraving. It’s also important for glass colouring and anti-fouling coatings. It is safe to say that the chemical is employed in almost every business that exists.

Sample Questions

Question 1: What is copper sulphate used for?

Answer:

CuSO₄.5H₂O, the compound’s pentahydrate, is employed as a fungicide since it can kill a wide range of fungus. Fehling’s and Benedict’s solutions include copper sulphate. With the use of this chemical, blood samples can be analysed for illnesses such as anaemia.

Question 2: What makes anhydrous copper sulphate white and pentahydrate copper sulphate blue?

Answer:

The water molecules around the Central Metal (Cu) serve as ligands in hydrated CuSO₄, resulting in a d-d transition and so emitting blue colour in the visible area, making hydrated CuSO₄ seem blue. Because anhydrous CuSO₄ has no water during crystallisation, it preserves its white colour.

Question 3: Is copper sulphate a solid or an aqueous solution?

Answer:

Copper(II) sulphate is a hydrated, blue solid with water molecules attached to it. When it is anhydrous – that is, when it is not molecularly coupled to water – it turns yellowish. When it is hydrated, five molecules of water are normally linked to one cooper sulphate molecule. Heating the CuSO₄ causes it to dehydrate.

Question 4: Write a note on the physical state of copper sulphate

Answer:

The chemical is a blue solid that is present in aqueous solution. That is, the substance’s molecules are only weakly linked to one another. It appears yellowish in its anhydrous state. When a chemical isn’t coupled to a water molecule, this happens. The chemical, on the other hand, has five water molecules bound to it in its hydrated state. The chemical dissolves when heated. Because they both disintegrate when heated, both the anhydrous and pentahydrate forms dissolve. As a result, a specific boiling point cannot be given for them.

Question 5: What’s the difference between pentahydrate blue and anhydrous white?

Answer:

The purest form of copper sulphate is anhydrous copper sulphate, which is white. Because the water molecules are confined in its ionic lattice, the compound takes the shape of a dry solid. It has the unusual feature of turning blue when water is added to it. The presence of water is detected by this type of colour shift. The hydrated form of the chemical, pentahydrate copper sulphate, emits a blue light. It does so due to the presence of water molecules, which causes a d-d transition in its structure.