Zinc Sulphide Formula – Structure, Properties, Uses, Sample Questions

Théodore Sidot, a French chemist, discovered the phosphorescence of ZnS in 1866. A. E. Becquerel, a luminary in the field of luminescence research, presented his findings. Ernest Rutherford and others utilized ZnS as a scintillation detector in the early days of nuclear physics because it emits light when excited by x-rays or electron beams, making it ideal for X-ray screens and cathode ray tubes. Because of this feature, zinc sulphide was helpful in the dials of radium timepieces.

Zinc sulphide, abbreviated ZnS, is an inorganic compound with the chemical formula ZnS. Sphalerite, the most prevalent mineral form of zinc, is the most common type of zinc found in nature. Although impurities make this mineral appear black, the pure component is white and is widely used as a pigment. In its thick synthetic form, zinc sulphide can be transparent and is used as a window for visual and infrared optics.

What is Zinc Sulphide?

It’s a white or yellowish-white crystal that can be found. Sphalerite is a greyish white mineral that crystallizes in a greyish white crystal. Insoluble in water, ZnS is also denser than water. 

Zinc blende, commonly known as sphalerite, is a mineral that can be found in nature. It is made up of zinc sulphide and iron. The production of ZnS can be achieved by burning a sulfur-zinc mixture. When zinc sulphate combines with sodium sulphide or hydrogen sulphide gas in any Zn²⁺ solution, insoluble ZnS forms. Because of its bright property, it has a wide range of applications.

Structure of Zinc Sulphide

The dichotomy between two primary crystalline forms of ZnS is a good example of polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. Zinc blende or sphalerite are other names for the more stable cubic form. The hexagonal form is known as wurtzite, a mineral that may also be created synthetically.

Physical Properties of ZnS

1. Zinc is typically found in larger, more complicated minerals.
2. When secluded, it is an extremely gleaming, whitish-blue metal.
3. The metal is less soft than copper and has fewer uses.

Preparation of ZnS

Zinc sulphide is typically made from byproducts of other processes. Common sources are smelter, slag, and pickle liquors. It’s also a byproduct of the methane-to-ammonia conversion process, where zinc oxide is used to remove hydrogen sulphide impurities from natural gas:

ZnO + H₂S → ZnS + H₂O

Applications of ZnS

With the addition of a few ppm of a suitable activator, zinc sulphide exhibits intense phosphorescence and is currently employed in a variety of applications ranging from cathode ray tubes to X-ray screens to glow-in-the-dark items. The result of using silver as an activator is a brilliant blue colour with a maximum wavelength of 450 nanometers. Copper-doped zinc sulphide is also used in electroluminescent panels. It also emits phosphorescence induced by impurities when exposed to blue or ultraviolet light.

Zinc sulphide is also utilized as an infrared optical material, transmitting wavelengths ranging from visible to just over 12 micrometers. It can be used as a lens or as a planar optical window. It is synthesized as microcrystalline sheets from hydrogen sulphide gas and zinc vapor and offered as FLIR-grade (Forward Looking Infrared), with the zinc sulphide in a milky-yellow, opaque form.

Semiconductor properties

Both sphalerite and wurtzite are inherent semiconductors with a broad bandgap. These are typical II-VI semiconductors with structures similar to many other semiconductors, such as gallium arsenide. At 300 kelvins, the cubic form of ZnS has a bandgap of roughly 3.54 electron volts.

Sample Questions

Question 1: What are the benefits of taking zinc?

Answer:

Zinc, a mineral found in your body, aids in the normal functioning of your immune system and metabolism. Zinc is also required for wound healing and the development of taste and smell. Your body gets adequate zinc from a well-balanced diet.

Question 2: What are the harmful effects of zinc?

Answer:

A zinc deficiency can be dangerous to one’s health, but too much zinc can also be damaging. The most prevalent kind of zinc poisoning is excessive zinc consumption, which can cause both acute and chronic symptoms.

Question 3: Give some applications of zinc.

Answer:

Zinc is essential for the human body to properly grow and maintain itself. It is required for immunological function, wound healing, blood clotting, thyroid function, and other processes and is found in a range of systems and biological events.

Question 4: Explain why zinc has a low melting point?

Answer:

Iron’s d orbital is only half filled, whereas zinc’s d orbital is completely filled. Zn is significantly larger than Fe, therefore its valence electrons are less restricted to the nucleus, regardless of the screening effect.

Question 5: Does Zinc rust in water?

Answer:

Zinc, like all ferrous metals, corrodes when exposed to air and water. Zinc, on the other hand, corrodes steel at a far slower rate. Zinc, like other ferrous metals, corrodes or rusts at variable rates depending on its environment.