[Chemistry Class Notes] on Zinc Pdf for Exam

Zinc is one of the transition earth metals which has a lustrous bluish-white colour. The zinc symbol is represented as Zn.  The Zn atomic number is 30. The abundance of the zinc element is estimated at almost 65 grams for every ton of the Earth’s crust. The word ‘zinc’ has a German origin whereas its exact derivation goes beyond the Persian word ‘sing,’ which means stone.

Zn in chemistry is a very important element and has several chemical properties.

Zn + 2HCl → ZnCl2 + H2 

2Zn + O2 → 2ZnO

• Zinc consist of five different natural stable isotopes

• These isotopes include; 64Zn, 66Zn, 67Zn, 68Zn and 70Zn

• Zinc has the lowest melting point after Cadmium and Mercury among all the  transition metals

• Zinc does not react with water directly. However, metallic zinc can react with oxygen present in the air in the presence of water vapour and thus, form zinc hydroxide.

Zn + 2H2O → Zn(OH)2 + H2

Chemical Properties of Zinc

Uses of Zinc

Zinc is one of the heavily used metals within the industry. Here is a list of some of the applications of zinc:

• The majority of the zinc is used in the manufacturing of zinc oxides as well as creating roofing materials

• Zinc oxides are mainly used as an additive to rubbers for the production of tires. This helps to withstand higher temperature as well as prevent any unnecessary wear and tear

• Zinc is also used in galvanizing other metals such as iron and steel. It prevents iron from rusting. On the other hand, galvanized steel is mainly used in manufacturing vehicles

• Alloys of metals are also formed using zinc. Some of the examples include nickel silver, brass, and even aluminium solder

• Zinc is also used in the production of die-casting. It plays an integral part in electronic hardware.

• Zinc oxide has also found its way into cosmetics, inks, pharmaceuticals, and even plastics

• Zinc sulfide is used for making fluorescent lights, x-ray screens as well as luminous paints

 Biological Significance of Zinc

The zinc atomic structure plays an integral role in every other living organism. In fact, almost 20 metalloenzymes have an active site formed through zinc. About 2.5g of zinc is present in an average human body, whereas we consume almost 15 milligrams per day. Some of the most common sources of zinc in food include beef, lamb, sunflower seeds, herrings and cheese.

On the contrary, zinc has carcinogenic properties too. Inhaling zinc (II) oxide can cause ‘zinc chills’ or commonly known as ‘oxide shakes.’

Physical properties of Zinc

Some of the most astounding physical properties of zinc include:

• At normal room temperature, it remains brittle with a crystalline state

• One of the properties of zinc is that when heated between 110oC to 150oC, it becomes malleable and ductile

• Zinc is highly reactive with dilute acids causing the release of hydrogen

• Zinc also shows its reactive properties while combing with oxygen or any other non-metal

Most Common Zinc Compounds

It is imperative to understand that the majority of the zinc compounds are widely used in organic synthesis. Below is a list of some of the most widely used zinc compounds:

• Zinc halogenides (fluoride, bromide, chloride, iodide)

• Zinc carbides

• Phosphides

• Sulfite, selenide, zinc arsenide

• Thiocyanates, cyanides and thiosulfates

• Ammonia complexes

• Hydroxo-zincates: amphoteric compounds formed from hydroxide and zinc oxide

 Interesting Facts about Zn Element

Here is a list of some of the most interesting facts about zinc that are worth mentioning:

• The 24th most common element that one can find on Earth’s crust is zinc

• Zinc contributes to almost 0.0075% of the entire Earth’s crust

• Zinc is also available in seawater, although it’s about 30 parts per billion

• The first known use of zinc dates back to 1000 BC

• The majority of the zinc (95%) are mined within ore deposits of sulfide

• Zinc is the fourth most commonly used metal within the industry

• Current zinc production includes 70:30; mining and recycling ration

• In 1746, Marggraf defined the zinc atomic structure while proclaiming it has a distinct element