Wednesday, March 20, 2013

Breaking atomic bonds

Solids are characterized by incompressibility, rigidity and mechanical strength. This represent the molecules, atoms or ions that make up a solids which are closely packed. They are join together by strong cohesive forces and cannot move at random. Thus, in solids we have well ordered molecular atomic or ionic arrangements. Thus, it is extremely hard to break atomic bonds between these molecules.
Some solids like sodium chloride NaCl2, sulphur S, and sugar (carbohydrates),  besides being incompressible and rigid, have also characteristic geometrical forms. Such substances are known be a crystalline solids. The X-ray crystallography studies reveal that their ultimate particles such as molecules, atoms or ions are arranged in unusual pattern throughout the entire three-dimensional (3D) network of crystal. This definite and ordered arrangement of molecules, atoms or ions lengthens over a large distance making it extra difficult in breaking atomic bonds.

The natural history of the Inter-atomic Force resulting in the breaking atomic bonds


Basically, an atom consists of a tiny positively charged body, located at its center called as nucleus. The nucleus, though small have all the protons and neutrons. Since the mass of an atom entirely owing to the presence of protons and neutrons, it is evident that almost the entire mass of an atom resides in the nucleus.
Between the atoms or ions or molecules the inter-atomic bonds is present. This type of breaking atomic bonds is set up by equilibrium between attractive and repulsive forces with the remaining force being zero (0). When the breaking atomic bonds is at stabile. It is evident that the atoms are far apart from the attractive forces between these molecules so it will govern and when they are very close packed together the repulsive force will becomes higher; both these help in ruining away as the separation increases. This report proves that the breaking atomic bonds result from inter-atomic force, as a function of atom separation. Fig 1: Representation of bonds between two molecules
bonds

Breaking atomic bonds is also characterized by bond energies


Enthalpy formation of the bond.
Bond energy for any particular type of bond in a compound may be defined as the average amount of energy required to dissociate (to break) one mole, viz., Avogadro’s number of bonds of that type present in the compound. Bond energy is also called the enthalpy of formation of the bond.

Sub-atomic particles

Introduction
Subatomic particles when considered in physics and chemistry refers to  the smaller particles which makes up the  nucleons and atoms.  Two types of subatomic particles are present in nature. The first one is the elementary particles, which are not composed of other particles, and composite particles. Particle physics and nuclear physics make a study on these particles their interactions. This term describes the behavior of matter and energy at the molecular scales of quantum mechanics. According to uncertainty principle it has been concluded that analyzing of particles at different scales will require a statistical approach.

Types of subatomic particles

Elementary particles
Elementary particles present in the Standard Model include
  • Six "flavors" of quarks: up, down, bottom, top, strange, and charm;
  • Six types of leptons are present namely electron, electron neutrino,  tau, tau   neutrino, muon, muon neutrino,;
  • Twelve gauge bosons (force carriers) are present namely the three W and Z bosons of the weak force, the photon of electromagnetism, and the eight gluons of the strong force.
Composite particles
The bounded states of two or more elementary particles form a composite particle. For instance, two up quarks and one down quark constitute a proton, while two neutrons and two protons make up the atomic nucleus of helium-4. The composite particles consist of all hadrons, a group composed of baryons (e.g., protons and neutrons) and mesons (e.g., pions and kaons). Hundreds of subatomic particles are known till date. The cosmic rays interacting with matter produces the majority of sub atomic particles or they are produced in particle accelerators by scattering processes.

Energy of subatomic particles

According to Einstein’s hypothesis, matter and energy are analogous. Matter can be expressed in terms of energy and vice-versa is also possible. Energy can be transferred by only two types of mechanisms which are known as waves and particles. Light can be expressed both as particles and waves. This type of paradox is termed as Wave-particle Duality Paradox. It has been established that all particles also have an associated wave nature. This is true for both elementary and compound particles. Few laws have been derived which explain how particles collide and interact.

Atomic radii

Atomic  radii  may be defined as  the distance between the nucleus and the outermost  electronic level of the atom. Since electrons are considered as the negatively charged electronic cloud there is no well defined boundary  for an atom.The diffused  nature of the electron cloud  makes it difficult  to give exact definition of  atomic size or atomic radii.

Introduction: Atomic radii

atomic radii
Thus  the atomic radii is an arbitrary  concept and is influenced by the nature of neighbouring atoms.

Types of atomic radii

As  there  is   no exact definition for the atomic radius, a number of radii have been defined for an atom. They are  Covalent radius, Crystal radius (otherwise called as metallic radius)  Vander Waal radius (otherwise called Collision radius). Let us learn one by one.

Covalent radius

 Covalent  Radius:
       Covalent radius  is used to measure the  atomic radii of  non- metals. The atomic  radius of  a non- metal is calculated from the  covalent bond length. In case of  homonuclear diatomic molecules ( type AA) , like F2, Cl2,Br2 ....etc half of the covalent bond length is taken as atomic radius. For example the value of  Cl - Cl  bond idstance is 1.98 Ao  half of the distance 0.99 Ao is taken as the  atomic radius of  chlorine
       Another example: measuring the atomic radius of  carbon in diamond. The value of  C- C bond distance in the diamond is 1.54 Ao half of the  distance 0.77 Ao  is considered as the  atomic  radius of carbon atom.

Heteronuclear diatomic  molecule:
      In the calse of heteronuclear diatomic  molecule of  AB type (example CCl4 , SiC ..etc) bond length  distance d(A-B) is given by
                   d (A -B)    =  r(A)  + r(B)
      r(A)   and  r(B) are the  covalent radii of  A and  B  respectively.
     Example:    The experimental value of   d(C-Cl)  in CCl4  molecule is  1.76 Ao
                  d (C-Cl)  =  r (C) + r(Cl)
                         r(C) =  d(C-Cl) - r(Cl)
                         r(C)       =  1.76 Ao -  r(cl)
                         if  r(cl)  is  given, then the covalent radius of carbon atom  can be calculated by subtracting the  covalent radius of  Cl from the  d(C-Cl) bond length.The covalent radius of Cl atom can also be obtained, provided that covalent radius of C atom is known
Crystal Radius:
      It is otherwise called as  Atomic or Metallic radius, and defined as  one half of  the distance between the nuclei of two adjacent metal atoms in the metallic close-packed crystal lattice. For example  the internuclear distance between  two adjacent Na atoms in a crystal of sodium  metal is  3.80 Aoand hence the atomic radius of a Na metal is  half of the  distance, that is  3.80 Ao/ 2                  =  1.90 Ao
      since there  are weak  bonding forces between the metal atoms, the metallic radii are higher than the  single bond covalent  radii and at the same time  the metallic radii are smaller than  the vander Waal radii since the  bonding forces in the metallic crystal  lattice  are much staonger than the vaner waals forces
Vander Waal Radius:
      The name is  derived from theVander  Waal forces which is  found in noble gases.This  type of atomic radii is other wise  called Collision Radius. Tthe distance  between the two non-bonded  isolated  atoms  or the distacnce between  two non-bonded  atoms belonging to two adjacent molecules of an element  in the solid state is called Vander Waals distance  while half of  this  is called vader Waals Radius.
 Example :  The vander Waals distance of Cl2 molecule =   3.6 A half of  this value is  1.8 Ao  and  1.8 A o  is the Vander Waal radius of chlorine  atom.
                   It is to be noted  that the vander Waal radius  of an element  is higher than its covalent radius. Example the measured Vander Waal radius of chlorine is 1.8 Ao  and the  covalent radius  is  0.99 Ao
                  The variation in the atomic radii can be explained as follows.
                  When two chlorine  atoms are  just in contact with each other and  there is no bond between them,  now the distance between nuclei of those two chlorine atoms is called  the vander Waals  distance (3.6 Ao) and  half of it ( 1.8 Ao) is called  vander Waals radius.
                 where as when the electron clouds of the two chlorine atoms merge with each other to form chlorine molecule by forming covalent bond between them, the distance (covalent bond length) between them further decreases and  the distance become 1.8 Ao and half of it  0.99 Ao is the covalent radius.
                 Thus while describing  the atomic radii of various atoms, any of the radii described above can be used.

Dalton's Atomic Theory

When scientists started exploring matter, they realised that matter can be divided into smaller and still smaller particles. What was the ultimate particle like? They discovered that the smallest particle of an element that maintains its chemical identity through all chemical and physical changes is called and 'atom'.

John Dalton (1766 - 1844) can rightly be called the father of the Modern Theory on Atoms. He proposed his Atomic Theory in 1808, i.e., almost 200 years back. He did not have the help of sophisticated instruments that are available today to the scientists. Hence, many of his proposals, have been modified and updated. Over the years, substantial changes have taken place regarding the atomic theory, yet some of the assumptions that Dalton made are still held valid.
John Dalton

Dalton's Atomic Theory

John Daltons Atomic Theory provided a simple theory of matter to provide theoretical justification to the laws of chemical combinations in 1805. The basic postulates of the theory are:
  • All substances are made up of tiny, indivisible particles called atoms.
  • Atoms of the same element are identical in shape, size, mass and other properties.
  • Each element is composed of its own kind of atoms. Atoms of different elements are different in all respects.
  • Atom is the smallest unit that takes part in chemical combinations.
  • Atoms combine with each other in simple whole number ratios to form compound atoms called molecules.
  • Atoms cannot be created, divided or destroyed during any chemical or physical change.

Wednesday, March 13, 2013

Electrolysis of aqueous solutions

Introduction:
Electrolysis is a process of breaking down (or decomposes) a chemical compound into its elements by using an electric current. The electric current is passed through an electrolytic cell, which consists of electrodes and electrolyte. Oxidation or reduction reactions occur in these electrodes. Electrolyte is a substance which contains free ions that make the substance electrically conductive. Electrolyte can be aqueous solution of molten ionic compound or the aqueous solution of ionic compound, alkali, or an acid. Hence electrolysis can be of two types
i) electrolysis of molten ionic compound
ii) Electrolysis of aqueous solutions.
Consider the example of sodium chloride (NaCl). Molten sodium chloride is obtained when we heat it till it melts. Whereas if, sodium chloride is dissolved in water, gives the aqueous solutions of sodium chloride. Solution of water of a substance is called the aqueous solution. Since the aqueous solution contains more than one type of ions, electrolysis of aqueous solutions is entirely different from that of molten electrolyte.

Electrolysis of aqueous solutions:


i)   Electrolysis of aqueous sodium chloride :
In the electrolysis of aqueous solutions, not only sodium chloride will dissociate into Na+ and Cl-, but some of the water molecules will also decompose to give hydrogen (H+) and hydroxide ions (OH-). The reaction of electrolysis of aqueous solutions (of NaCl) can be written as follows,
              NaCl ---> Na+ + Cl-
               H2O ---> H+ + OH-
In an aqueous solution, there can be more than one positive and one negative ion. There is a selective discharge, which means when there is a movement of ions to cathode or anode, only one negative ion and one positive ion will be selected to be discharged.

Electrolysis of aqueous solutions:


ii)  Electrolysis of Aqueous Sulphuric Acid
It is one of the examples of electrolysis of aqueous solutions.
The aqueous sulphuric has three types of ions. They are hydrogen ions (H+), sulphate ions (SO42-), and also hydroxide ions (OH-) from the water. The equation can be written as follows,
H2SO4 + H2O --> 2H+ + SO42- + H+ + OH-
Diagram showing electrolysis of water:
Electrolysis of water
The apparatus used for the Electrolysis of Aqueous Sulphuric Acid
There is more than one type of ion moving to the electrode, there is preferential discharge (also called as selective discharge) takes place.
The chemical reactions occur at anode and cathode is given in the table below.

At cathode

At anode

Here, each hydrogen ion (H+) gains electron and becomes hydrogen atom.

Two of the hydrogen atom will combine and produce hydrogen gas molecule.

Equation:
2H+ + 2e ---> H2

 

Here there is a choice of sulphate ions (SO42-) or hydroxide ions (OH-)

Oxygen is gives off at anode, because of hydroxide ion is easier to discharge.

Equation:
OH- + 4e ---> O2 + H2O

 


Note:
When the electrolysis of aqueous solutions of dilute acids or alkalis is done, the volume of hydrogen given off at the cathode is approximately twice that of the oxygen gas at the anode.

Aqueous hydrogen fluoride

Introduction:
Electrolysis is a process of breaking down (or decomposes) a chemical compound into its elements by using an electric current. The electric current is passed through an electrolytic cell, which consists of electrodes and electrolyte. Oxidation or reduction reactions occur in these electrodes. Electrolyte is a substance which contains free ions that make the substance electrically conductive. Electrolyte can be aqueous solution of molten ionic compound or the aqueous solution of ionic compound, alkali, or an acid. Hence electrolysis can be of two types
i) electrolysis of molten ionic compound
ii) Electrolysis of aqueous solutions.
Consider the example of sodium chloride (NaCl). Molten sodium chloride is obtained when we heat it till it melts. Whereas if, sodium chloride is dissolved in water, gives the aqueous solutions of sodium chloride. Solution of water of a substance is called the aqueous solution. Since the aqueous solution contains more than one type of ions, electrolysis of aqueous solutions is entirely different from that of molten electrolyte.

Electrolysis of aqueous solutions:

i)   Electrolysis of aqueous sodium chloride :
In the electrolysis of aqueous solutions, not only sodium chloride will dissociate into Na+ and Cl-, but some of the water molecules will also decompose to give hydrogen (H+) and hydroxide ions (OH-). The reaction of electrolysis of aqueous solutions (of NaCl) can be written as follows,
              NaCl ---> Na+ + Cl-
               H2O ---> H+ + OH-
In an aqueous solution, there can be more than one positive and one negative ion. There is a selective discharge, which means when there is a movement of ions to cathode or anode, only one negative ion and one positive ion will be selected to be discharged.

Electrolysis of aqueous solutions:

ii)  Electrolysis of Aqueous Sulphuric Acid
It is one of the examples of electrolysis of aqueous solutions.
The aqueous sulphuric has three types of ions. They are hydrogen ions (H+), sulphate ions (SO42-), and also hydroxide ions (OH-) from the water. The equation can be written as follows,
H2SO4 + H2O --> 2H+ + SO42- + H+ + OH-
Diagram showing electrolysis of water:
Electrolysis of water
The apparatus used for the Electrolysis of Aqueous Sulphuric Acid
There is more than one type of ion moving to the electrode, there is preferential discharge (also called as selective discharge) takes place.
The chemical reactions occur at anode and cathode is given in the table below.

At cathode

At anode

Here, each hydrogen ion (H+) gains electron and becomes hydrogen atom.

Two of the hydrogen atom will combine and produce hydrogen gas molecule.

Equation:
2H+ + 2e ---> H2

 

Here there is a choice of sulphate ions (SO42-) or hydroxide ions (OH-)

Oxygen is gives off at anode, because of hydroxide ion is easier to discharge.

Equation:
OH- + 4e ---> O2 + H2O

 


Note:
When the electrolysis of aqueous solutions of dilute acids or alkalis is done, the volume of hydrogen given off at the cathode is approximately twice that of the oxygen gas at the anode.

Wednesday, March 6, 2013

Group 14 elements: the carbon family

Introduction:
The carbon family elements in the periodic table that belong to the Group 14 or the IV A family are carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb) and Ununquadium (Uuq). The carbon family is unique in having one metal, three metals and two metalloids.

Properties of individual elements of the carbon family may be represented by the table below


Name of the ElementRepresented by symbolAtomic numberAtomic weightTypeElectronic configuration of the elements
CarbonC612.011Non-metal[He]2s22p2
SiliconSi1428.0855Metalloid[Ne]3s23p2
GermaniumGe3272.61Metalloid[Ar]3d104s24p2
TinSn50118.710Metal[Kr]4d105s25p2
LeadPb82207.2Metal[Xe]4f145d106s26p2
UnunquadiumUuq114289Metal[Rn]5f146d107s27p2
The electronic configuration in the valence shells of the carbon family elements is ns2, np2.  Sharing of electrons is seen in most of the elements of the carbon family. As the size of the atom is increased, the tendency of the elements to lose electrons decreases. Similarly, the tendency of losing electrons decreases with the increase in the atomic number among the elements of the carbon family. The oxidation states of the elements in the carbon family are usually +4 and +2 for heavier elements because of the inert pair effect.

Individual elements in the carbon family:

Carbon: The first element known to humans and is the fourth most abundantly found element. Carbon exists both in elemental form and as allotropes, the most common being diamond and graphite.
Silicon: Crystalline metalloid that forms the foundation for the age of semiconductors. The common compound SiO2 is abundantly found in earth’s crust.
Germanium: Used in manufacturing of semi-conductor devices. Rarely present in earth’s crust.
Tin: When pure, the metal is silvery white and is very soft. Forms low-melting alloys called solders that connect electric circuits.
Lead: Readily combines with the oxygen in the air forming Pb2O, which results in the dulling of the surface on exposure to air.

Conclusion on carbon family:

The elements in the carbon family include a non-metal, two metalloids and three metals, varying greatly in their physical and chemical properties. These elements occur as elemental forms and in the form of compounds in nature. The elements of Group 14 are relatively non-reactive and usually tend to form covalent compounds with exceptions of tin and lead that form ionic compounds.

Common chemical formulas


Introduction: 
In order to study or describe the elements and molecules in simpler forms, chemical formulas are extensively used. For example simplest formula for water is H20, where H represents hydrogen and O is oxygen and subscript 2 indicates the two atoms of hydrogen element joined together to form a molecule.
Applications of chemical formulas
  • It is used to explain the kinds of atoms and their numbers in compound (or an element).
  • The atoms of every element are characterized by different letters.
  • A subscript is used when more than one atom present in a specific element
  • It states the chemical composition of a compound by means of chemical symbols

Common chemical formulas for everyday substances and some common acids

NaCl- Table salt, NH3 (Ammonia) and CH4 (methane) used for cleanser and a gaseous fuel, C6H12O6 - table sugar or glucose, Air contains mixture of N2, O2, CO2, and other traces gas, H2O2 (hydrogen per oxide)- used as a antiseptic and to bleach or lighten hair, Aspirin - C9H8O4, Hydrochloric acid (HCl),Nitric acid (HNO3),Hydrocyanic acid (HCN), Perchloric acid (HClO4), Sulfuric acid (H2SO4),Carbonic acid (H2CO3)

Some important common chemical formulas are given below

Acetic acid - CH3COOH, Acetone - CH3COCH3, Ammonium hydroxide - NH4OH, Aspirin - C9H8O4, Benzene - C6H12, Boric acid - H3BO3,Butane - C4H10, Caffeine - C8H10N4O2, Calcium carbonate - CaCO3, Calcium chloride - CaCl2, Calcium hydroxide - Ca(OH)2, Calcium oxide – CaO, Calcium sulfate - (CaSO4), Glucose - C6H12O6, Hydrochloric acid - HCl, Hydrofluoric acid - HF, Magnesium sulfate - MgSO4, Manganese dioxide - MnO2, Methane - CH4, Naphthalene - C10H8, Oxalic acid - H2C2O4 , Potassium nitrate - KNO3, Potassium sodium tartrate - NaKC4H4O6 , Potassium oxide - K2O, Potassium sulfate - K2SO4, Sodium bicarbonate - NaHCO3, Sodium chloride – NaCl, Sodium hydroxide - NaOH, Sodium sulfate - Na2SO4, Sodium phosphate - Na3PO4, Sodium tetraborate - Na2B4O7, Sucrose - C12H22O11, Sulfuric acid - H2SO4, Water - H20, Zinc chloride- ZnCl

Chemical compounds


Introduction:
We are going to see about the important chemical compounds.  A chemical compound is one of the pure chemical substance composed of molecules and formed combination of more than one different chemically bonded chemical elements.  Elements are more stable when the compounds are combined to form together.  Some important chemical compound names are organic compound, inorganic compound, biomolecules, organometallic compounds and so on.

Organic compound- Important chemical compound

Some important chemical compounds are
Acetaldehyde:  It is an organic chemical compound and also occurs in coffee.  The general formula is CH3CHO.
Benzene:  Benzene is also an organic chemical compound and it is flammable liquid.  General formula is C6H6.
Butene:  Butylene or butene is an chemical compound.  It is colorless gas.  General formula is C4H8.
Ethene:  Ethylene or ethene is one of the chemical compound.  It is flammable gas and colourless.  The general formula of ethene is C2H4.
Formic acid:  Methanoic acid or formic acid is the carboxylic acid.  The general formula of formic acid is HCOOH.

Inorganic compound- Important chemical compound

Some important chemical compounds are
Aluminium chloride:  Aluminium chloride (AlCl3) is the combination of aluminium and chlorine.
Ammonia:  Ammonia (NH3)is the chemical compound.  It is colourless gas and pungent odour.
Calcium chloride:  It is one of the important chemical compound.  CaCl2 is the combination of calcium and chlorine compounds.
Chromic acid:  Collection of compounds. It is a powerful oxidized agent.
Gallium phosphate:  GaPO4 or (gallium orthophosphate) is a colourless crystal.
Hydrogen chloride:  HCl  combination of hydrogen and chlorine atom and soluble in water.
Magnesium oxide:  MgO is a moisture absorbent.  It used as raw material for making cement.
Nitrogen monoxide:  It is a chemical compound with chemical formula NO.
Biomolecules:

Some important chemical compounds are
Acetic acid:  The general formula is CH3COOH.  It is pungent smell and sour taste.
Cellulose:  The general formula is C6H10O5.  It is one of the organic compound.

Air chemical equation

Introduction :
Air is usually made up of a mixture of so many gases. Air comprises slightly over 20% of oxygen (O2) and in relation to 78% nitrogen (N2). Air also contains surplus quantities of Carbon Dioxide (about 0.03%) and even smaller quantities of other inert gases like Helium, Neon, Argon, etc. It has some low level Ozone O3. Air usually exists as a mixture of all these gases it does exist in the compound form. It also contains small and varying quantity of water vapor. Which we are looking as clouds in the sky.The air chemical equation are give in Table 1
air chemical equation

Air chemical equation:Chief constituent of gases

The chief constituent of air is nitrogen gas followed by oxygen
The first two gases nitrogen and oxygen make up 99.0% of the atmosphere by volume.
Nitrogen is moderately inert because of its strong triple bond holding the atoms jointly in the molecule. Whereas, the oxygen gas is synthesized by photosynthesis and removed by combustion and respiration.

Types of Air chemical equation:

The types of air chemical equation as follows
Reaction with Acetaldehyde: Oxygen gas is used in the preparation of acetaldehyde (ethanol) involves the following steps.
2CH3CH2OH + O2 →2CH3CHO + 2H2O
Further oxidation of ethanoic acid with give rise to acetic acid which on further oxidation with carbon dioxide and water takes place on burning.
2CH3CHO + O2 → 2CH3COOH
Reaction with Aluminum: Secondly oxygen reacts with aluminum metal
Aluminum metal undergoes a combination reaction with O2 (g).
4Al + 3O2 →2Al2O3
Reaction with Copper hydroxide: Copper (II) hydroxide degraded into copper (II) oxide and water when heated.
Cu (OH) 2 → CuO + H2O
Reaction with Heptanes: Heptanes, burns in air to give carbon dioxide
C7H16 + 11O2 → 7CO2 + 8H2OH
Reaction with methyl ter butyl ether: The gasoline additive MTBE (methyl tert-butyl ether), C5H12O2 (l), burns in air.
C5H12O2 + 7O2 →5CO2 + 6H2O
Physical properties of Air chemical equation:
  • Oxygen exhibits its Compressibility that is isothermal properties with the chemical compounds.
  • Oxygen shows high conductivity towards air, water, and other fluids.
  • It has high density gradient against air, water and other fluids, various solids and other common liquids.
  • It is relatively rough to handle because of its high tensile strength.
Check my best blog Types of chemical reactions.

Types of chemical reactions

Introduction :
Chemical reaction is defined as the changing one set chemical reactions into other set of chemical reactions. There is no need to give input to the chemical reactions. Chemical reactions involves the transfer of electrons and the formation of chemical bonds. Reactants are the substance which are involved in the chemical reactions. Nuclear reactions are also takes place in the chemical reactions. There are three types of chemical reactions are present.

Different Types of Chemical Reactions:

There are three types of chemical reactions are present. The three types are defined in the following,
Oxidation reaction and reduction reaction:
Oxidation and reduction reaction are defined as one substance gets oxidised and the other substance gets reduced. Simply it is defined as the loss or gain of electrons. Some of the examples involves in this type of chemical reaction are,
1. Iron and oxygen reaction:
In this example, the ion reacts with the oxygen and it produces oxide. In this the oxidised substance is iron. The chemical reaction is as follows,
4Fe + 3O2 `->`  2Fe2O3
Where
            Fe = iron
            O2 = oxygen
            2Fe2O3  = oxide
2. Ethanol and oxygen reaction:
In this example, the ethanol reacts with the oxygen, thus producing an acid called ethanol. In this the oxidised substance is ethanol.
CH3 CH2 OH + [ O ]    `->` CH3COOH
Where,
CH3 CH2 OH = ethanol
[ O ] = other chemicals
CH3COOH = ethanoic acid
Acid – Metal oxide Reaction:
The formation of salt and water by using the reaction of acid and the metal oxide is called as the acid – metal reaction. The example of chemical reaction is, The acid hydrochloric acid reacts with the metal oxide iron oxide,thus producing  iron chloride and solvent water
3HCl + Fe2O3 `->` FeCl3 + 3H2O
HCl = hydrochloric acid
Fe2O3 = iron oxide
FeCl3 = iron chloride
H2O = water

Three types of chemical reaction

Acid – Base Reactions:
The formation of salt and water by using the reaction of acid and base are called as the Acid-Base reactions. The examples for this chemical reaction are ,
The acid hydrochloric acid reacts with the base sodium hydroxide, thus producing a salt called sodium chloride and solvent water
HCl + NaOH NaCl + H2O
Where,
HCl = hydrochloric acid
NaOH = sodium hydroxide
NaCl = sodium chloride
H2O = water

Another example,
The acid sulphuric acid reacts with the base potassium hydroxide, thus producing a potassium sulphate and the solvent water
H2SO4 + 2KOH K2SO4 + 2H2O
Where,
H2SO4 = sulphuric acid
KOH = potassium hydroxide
K2SO4 = potassium sulphate
H2O = water