Dear Gradians,
Here we will discuss Metals & their uses. One line questions are asked from this section in defence exams - AFCAT, Air Force Group X & Y, NDA etc.
Metals:
- Metals are good conductors of heat & electricity and are malleable and ductile.
- Gold and silver are the most malleable and best ductile metals.
- Silver is the best conductor of heat followed by copper.
- Aluminium and copper are good conductors of heat that’s why cooking utensils are made of them.
- Mercury offers high resistance to the flow of electric current.
- Sodium and potassium are so soft that they can be easily cut with a knife.
- Metals are electropositive in nature.
- Almost all the metal oxides are basic in nature but zinc oxide and aluminium oxide are amphoteric.
Alkali metals and their compounds
- Metals of the first group are alkali metals.
- This group lies in the s-block of the periodic table of elements as all alkali metals have their outermost electron in an s-orbital.
- Lithium, sodium, potassium, rubidium and cesium are alkali metals.
- These metals are stored under kerosene or liquid paraffin’s to protect them from the action of air.
Sodium chloride (NaCl):
- Commonly known as table salt
- Used in the manufacturing of sodium hydroxide and chlorine gas.
- It is used as a starting material in the manufacturing of caustic soda.
- It is used in the removing of ice from road, now a- days CaCl2 and MgCl2 are also used for this purpose.
Sodium hydroxide (NaOH):
- Used in the refining of bauxite material.
- Used in soap, dyes and artificial industries.
Sodium bicarbonate (NaHCO3):
- It is commonly known as baking soda.
- Used for wool washing.
- Used in the fire extinguisher.
Sodium carbonate (Na2CO3)
- It is commonly known as washing soda.
- Used for softening of hard water.
- The mixture of sodium carbonate and potassium carbonate is known as Fusion mixture.
Sodium Sulphate:
- It is commonly known as Glauber’s salt.
- It is used as a purgative.
Sodium thiosulphate:
- It is commonly known as Hypo and used in photography as a fixing agent.
Potassium carbonate:
- It is known as pearl ash.
Potassium hydroxide:
- Commonly known as caustic potash.
- Use in the preparation of soft soap.
- Its aqueous solution is known as potash Lye.
Potassium superoxide.
- Used in space capsules, submarines, and a breathing mask as it removes in carbon dioxide and carbon monoxide.
Alkaline Earth Metals and their compounds
The alkaline earth metals are six elements in column (group) 2 of the Periodic table.
They are beryllium (Be),magnesium(Mg),calcium (Ca), strontium (Sr),barium (Ba), and radium (Ra).They have very similar properties: they are all shiny, silvery-white, somewhat reactive metal at the same temperature and pressure.
- Mg(OH2) is known as milk of magnesia and use as an antacid.
Calcium oxide
- It is also known as quick lime.
- Used in the manufacturing of calcium chloride, cement, and bleaching powder.
Calcium sulphate (CaSO4):
The compound exists in three levels of hydration:
- anhydrous state (mineral name: "anhydrite") with the formula CaSO4
- dihydrate (mineral name: "gypsum") with the formula CaSO4(H2O)2.
- hemihydrate with the formula CaSO4(H2O)0.5
- It loses a part of water to form plaster of Paris.
- Plaster of Paris is a white powder which becomes hard on contact with water and is used in the manufacturing of statues.
Some Important Metals & Their Uses
Aluminium (Al):
- Ore of aluminium is bauxite.
- It is the third most abundant element in the earth’s crust.
- Used in the manufacturing of cooking utensils.
- Ammonal, a mixture of aluminium powder and ammonium nitrate is used as an explosive.
Tin:
- The ore of tin is Cassiterite.
- The process of converting white tin to grey tin is known as tin disease or tin plague.
- Used in the plating of iron to protect the iron from rusting.
- Tin amalgam is used in the manufacturing of mirrors.
Lead(Pb)
- The main ore of lead is galena.
- Use in the preparation of sulphuric acid through the chamber process.
- Lead acetate is known as sugar of lead.
Zinc(Zn):
- It is used in the galvanization process to prevent the rusting of iron.
- Zinc sulphide is used in the preparation of X-ray screens.
- Zinc oxide is known as philosopher wool.
Mercury(Hg):
- It is the only metal which is liquid at room temperature.
- It forms alloys with all other metal except iron and platinum.
Nickel(Ni):
- Silvery white soft metal.
- Used as an anode in Edison batteries.
Iron(Fe)
- Extracted from the haematite ore and do not occur in Free State due to its reactivity.
- Ferric chloride is used as a styptic to stop bleeding from the cut.
- Ferrous sulphate is used in making blue-black ink.
Stainless steel:
- It is an alloy of iron, chromium, and nickel.
- Used in making automobiles parts and utensils
Aim To Succeed With BYJU'S Exam Prep Offer | Get FLAT 30% off on Online Classroom Program
Use Code FEST30 | Avail Now
How to avail of this offer?
Click Here and use code FEST30.
More from us:
Important Study Notes for Defence Exams
Thanks
The Most Comprehensive Exam Prep App
Comments
write a comment