Metals

In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are sometimes described as a lattice of positive ions surrounded by a cloud of delocalized electrons. The traditional definition focuses on the bulk properties of metals.

The physical properties:

1. The physical properties make them useful for many purposes. For e.g. Copper is used in making electric wires, gold is used to make jewellery, stainless steel is used to make pots, pans, etc
2. They react with nonmetals to form ionic bonds. For e.g. Sodium Chloride (NaCl)
3. They are a good conductor of electricity which means that they can conduct electricity due to the free moving electrons present in them. Copper is used as wiring as it is a good conductor of electricity.
4. They have high melting points and high boiling points as they have strong metallic bonds.
5. All are physically lustrous. They have a lustre that makes them shine. Gold is used for making jewellery.
6. They are hard, they can’t be broken easily and require a lot of energy and strength to break. Iron is used to make cars, buildings, ships, etc.
7. They weigh a lot as they have a high density. Metals are heavy for their size.
8. They don’t have the flexibility and have tensile strength. Metals can’t be stretched.
   Metals are great conductors of heat. That’s why pots, pans, vessels are made of metals.

The chemical properties:

1. Their density is usually high.
2. They are malleable and ductile.
3. They form an alloy.
4. Some of them react with air and corrode For e.g. Iron.
5. They are good conductors of heat and electricity. Lead is an exception.
6. Generally, they are in a solid-state at room temperature. Except for Mercury. Mercury is in a liquid state.
7. Many metals produce metal oxide by burning in the oxygen of the air. Highly reactive metals react violently when they’re burnt in oxygen.
8. They produce metal oxide and hydrogen gas while reacting with water.
9. Not all of them react with water. However, highly reactive of them like sodium and potassium react with water violently and an exothermic reaction takes places where the hydrogen immediately catches fire.
10. Metals like zinc, iron react with sulphuric acids to produce hydrogen gas. Fe + dil. H2SO4    →    FeSO4 + H2
11. Some metals Mg Ca combine with oxygen to produce oxides. 2Mg   + O2  2MgO

Metallurgy

Metallurgy is defined as a process that is used for the extraction of metals in their pure form. The compounds of metals mixed with soil, limestone, sand, and rocks are known as minerals. These minerals are known as ores.

Metallurgical processes are:

1. Crushing of the ores
2. Pulverization of the crushed ore
3. The concentration of the ore
4. Calculations and roasting
5. Extraction of the metals
6. Refining

Iron

Iron is defined as an element used to create a strong metal, that can be magnetized, that rusts in moist air and that naturally occurs in the blood. Iron is the transition element and known as a d block element. It belongs to group VII of the periodic table. The electronic configuration of iron is: 1s2, 2s2, 2p6, 3s2, 3p6, 4s2,3d6 

Symbol: Fe

Atomic weight:26amu

Atomic no:55.84

Valency: 3 and 2

Occurrence: Iron is very rarely found in the free state but it occurs in a combined form. It is found in the body of living organisms. Ores of iron are Hematite and Magnetite.

Properties 

1. When iron is immersed in a copper sulphate solution, copper is liberated. Fe + CuSO4 → FeSO4 + Cu
2. When iron and chlorine is heated, it forms ferric chloride. 2Fe + 3Cl2 → 2FeCl3
3. The reaction of iron with acids Fe + dil. H2SO4 → FeSO4 + H2 , Fe + dil. 2HCl → FeCl2 + H2, 4Fe + dil. 10HNO3 → 4Fe (NO3)2 + NH4NO3 + 3H2O
4. When iron is exposed to moist air, a brown scale of rust is formed and rusting takes place in iron. The chemical formula of rust is (2Fe2O3.H2O)

Uses

1. It is used as making rods, pipes
2. It is used in the manufacture of steel
3. It is used in making household utensils
4. It is used as a catalyst in the chemical reaction.

Aluminium

Aluminium is a silvery-white, lightweight metal. It is soft and malleable. Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, window frames, beer kegs and aeroplane parts. This is because of its particular properties.

Symbol: Al

Atomic weight: 27amu

Atomic no: 13

Valency: 3

Ores: bauxite, feldspar, cryolite. The electronic configuration of iron is: 1s2, 2s2, 2p6, 3s2, 2p1,

Reaction of Aluminum with acids
2Al + 6HCl → 2AlCl3 + 3H2
2Al + 3H2SO4 → Al2(SO4)3 + 3H2
2Al + conc. 6H2SO4 → Al2(SO4)3 + 3SO2 + 6H2O

When aluminium is heated with nitrogen, then aluminium nitride is formed.
2Al + N2 → 2AlN

When aluminium is heated with chloride, then aluminium chloride is formed.
2Al + 3Cl2 → 2AlCl3

2Al + 3Cl2   →    2AlCl3

2Al + 3Br2   →    2AlBr3

2Al + 3I2   →  2AlI3

Uses

The uses of aluminium are as follows:

1. It is used in making coins.
2. It is used in electric cables.
3.  Aluminium foil is used in wrapping.

 

Copper

Copper, Cu, atomic number 29 is a ductile malleable reddish-brown corrosion-resistant diamagnetic metallic element; occurs in various minerals but is the only metal that occurs abundantly in large masses; used as an electrical and thermal conductor.

Symbol: Cu

Atomic weight:  67.57amu

Atomic no: 29

Valency:  1 and 2

The electronic configuration of iron is: 1s2, 2s2, 2p6, 3s2, 3p6, 4s1,3d10

Properties

1. With concentrated Nitric acid,
   Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
2. With dilute nitric acid 4Cu + 10HNO3 → Cu (NO3)2 + 2N2O + 4H2O
3. Reaction of copper with acids Cu + conc. H2SO4 → CuSO4 + 2H2O + SO2, 2Cu + conc. HCl → 2CuCl + H2, Cu + conc. 4HNO3 → Cu(NO3)2 + 2NO2 + 2H2O

Uses 

1. It is used for making electrical goods and cables
2. It is used for making coins, pieces of jewellers.
3. It is used for electroplating
4. It is used in the electrolytic process.

Silver

Silver is a precious metal and, like gold, often symbolizes riches and wealth. As a gemstone silver represents hope, unconditional love, meditation, mystic visions, tenderness, kindness, sensitivities, and psychic abilities.

Symbol: Ag

Atomic weight:  107.88amu

Atomic no:47

Valency:  1

Ores: Argentite, Horn silver, pyrolite. The electronic configuration of silver   is: 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10 4p6, 5s1, 4d10 

Properties

1. When silver is heated with bromine, then there is the formation of silver bromide.
   2Ag + Br2 → 2AgBrsilver

 

 Action with Sulphur:

2Ag + S    →     Ag2S (Silver Sulphide)

Action with halogen:

2Ag + Cl    →     2AgCl (Silver Chloride)

Action with nitric acid:

Ag + conc. 2HNO3 →     3AgNO3 + 2H2O +NO

(Silver Nitrate)

The mixture is called Aqua Regia.

2Ag + conc. H2SO4   →   Ag2SO4 +H2O + SO2

4Ag + conc. 4HCl + O2   →   4AgCl +2H2O

(Silver Chloride)

i. 3Ag + dil. 4HNO3  →   3AgNO3 + 2H20 +NO

Ag+ conc. 2HNO3   →   AgNO3 +H2O +NO2

Uses 

1. It is used for making coins, pieces of jewellers.
2. Silver bromide is used in photography.
3. It is used in the preparation of silver salts and medicine.
4. It is used for silvering mirror.

Gold

Gold is one of a kind metal. It is a member of the 'coinage metals' and sits in the same periodic table column as silver and copper. Gold is a soft, yellow metal with the symbol Au from the Latin 'aurum,' meaning 'shining dawn,' with an atomic weight of 79.

Symbol: Au

Atomic weight:197.2amu

Atomic no:79

Valency: 1 and 3

The electronic configuration of silver is: 1s2, 2s2, 2p6, 3s2, 3p6, 4s2,3d104p6, 5s2,4d10, 5p6, 6s1,4f14,5d10

Gold is called noble metal. Gold is found in the native state because it does not react with other elements in ordinary conditions.

Properties

Action with Acid:

2Au + 3HNO3 + 9HCl    →      3NOCl + H2O +2AUCl3

(Aqua Regia)                        (Nitrosyl Chloride)

 Action with Halogens:

2Au + 3Cl2    →     2AuCl3    

 Action with alkali Cyanide:

4Au + 8KCN + 2H2O     →     4K[Au (CN) 2] + 4KOH

(Potassium aurocyanide)

Uses 

1. It is used for electroplating
2. It is used to prepare alloys.
3. It is used for making pieces of jewellers.
4. It is used as ornaments.

Hydrocarbons and their derivatives

Hydrocarbons are the chemical compounds made by the composition of hydrogen and carbon. Example: Methane (CH4), Ethane (C2H6), Propene (C3H6), acetylene (C2H2) etc.

There are two types of hydrocarbons. They are:

1. Saturated Hydrocarbons: The hydrocarbons with single-bonded carbon atoms are known as saturated hydrocarbons. It consists of only one group i.e. alkane group. Example: Methane, Ethane, etc.

2. Unsaturated Hydrocarbons: The hydrocarbons with double bonded or triple bonded carbon atoms are known as unsaturated hydrocarbons. It consists of alkene and alkyne group. Example: Propene, Propyne, etc.

An alkene is an unsaturated hydrocarbon in which the two carbon atoms are connected by a double bond. The double bond is formed by the sharing of two pairs of electrons.  For eg: Methane, Propane etc

Alkynes are an unsaturated hydrocarbon in which the two carbon atoms are connected by a triple bond. The triple bond is formed by the sharing of three pairs of electrons. For Eg: Acetylene, Methyl acetylene etc.

Homologous series is defined as a group of organic compounds having similar structures and chemical properties in which the successive compounds differ by CH2 group.

The characteristics of homologous series are:

1. All the members of the same series can be represented by the same formula.

2. All members of the series show similar chemical properties.

3. Each excessive member of a homologous series differs by CH2.

4. All the members of the same series have the same functional group as alcohol (-OH), ether (-O-) etc.

Example. C2H6,C3H8

The functional group is defined as an atom or group of atoms which determines the chemical behaviour of organic compounds. The hydrocarbon unit derived by the removal of one hydrogen atom from alkane is called alkyl group. Metal is a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g., iron, gold, silver, copper, and aluminium, and alloys such as brass and steel).