The Chemical Formula for Aluminum

Aluminum belongs to group 13 of the periodic table. It was first discovered by Wohler in 1827. It is the third most abundant element in the earths crust. The atomic number of aluminum is 13. Aluminum forms a tri-positive ion i.e. Al3+. It is less electropositive than sodium and magnesium.

PROPERTIES OF ALUMINIUM

PHYSICAL PROPERTIES

1) Aluminum is a soft silvery white metal. The fresh metal on exposure to moist air loses its shining due to formation of oxide layer on its surface.

2) It is very light metal with specific gravity equal to 2.70.
Chemical Properties of Aluminium

(1) Action of air.

(a) Aluminum is not affected by dry air but in moist air a thin film of oxide is formed on its surface.

(b) It burns with oxygen with a brilliant white light with the evolution of heat

4Al +3O2 ----> 2Al2O3

(2) Action of water: Aluminum is not affected by pure cold water. However, saline water corrodes rapidly especially when it is hot. It decomposes boiling water. In the form of amalgam, it reacts more easily and rapidly with water and can decompose it even in cold.

2Al + H2O ----> 2Al (OH) 3+ 3H2

(3)Action of acids: Aluminum dissolves in dilute hydrochloric acid forming aluminum chloride with the evolution of di-hydrogen gas.

2Al + 6HCl  ----> 2AlCl3 + 3H2

Aluminum is not attacked easily by dilute sulphuric acid. This probably is due to insolubility of oxide layer (present on its surface) in the acid. However, it dissolves in hot and concentrated sulphuric acid to form sulphur dioxide.

2Al + 6H2SO4 ----> Al2 (SO)3 + 2SO2 + 6H2O
Uses of Aluminium

1)     Auminium is used for making electrical transmission cables.

2)     Aluminium powder is used as a reducing agent inj Goldschmidt aluminothermic process and thermite welding.

3)     It is used in making household utensils and novelty articles.

4)    Aluminium foil is used for wrapping soaps, cigarettes, confectionary, etc.

5)     It is used for making silvery paints for covering iron and other materials.

6)     It is used as dexidiser for removing blow holes in metallurgy.

7)     Due to low density, good thermal and electrical conductivity and resistance to corrosion, aluminium is used for making several alloys which are extensively used in automobile and automobile industries.

Chemical Reactions

The process of transformation of chemical substance to another is known as chemical reaction.

A chemical change involves the formation and cleavage of chemical bonds between atoms. Any chemical change can be described by using a chemical equation which gives complete idea about conversion of molecules during reaction.

Let’s elaborate; what is a Chemical reaction. It can define as change in bonding of reacting molecule to form new chemical compound by the formation of new chemical bonds.

The chemical substances take part in chemical reactions is called as reactant and newly formed substances are known as products. A chemical change can complete in one step or multi steps which can be described by using reaction mechanism. Chemical equation is the graphical representation of such a reaction which provides direction of reaction, physical states of reactant and products and the number of molecules taken part in reaction.

Different Types of Chemical Reactions and examples are as follow;

1. Combustion: Oxygen combines with substance to form carbon dioxide and water with a large amount of heat.

CH₄+ 2 O₂  CO₂ + 2H₂O

2. Synthesis: two or more chemical substance combines to form a more complicated one.

2Mg + O₂ 2MgO

3. Decomposition: A complex molecule decomposes in to simpler ones.

2HI  H₂ + I₂

4. Single displacement: one element trades places with another element in a compound.

Mg + 2 HClMgCl₂ + H₂

5. Double displacement: The anions and cations of two different molecules interchange and form two entirely different compounds.

BaCl₂ + H₂SO₄  BaSO₄ + 2HCl

6. Neutralization: A double displacement reaction between acid and base to form salt and water.

HCl + NaOH  NaCl + H₂O

There are a many observations which indicate a chemical change has occurred. These are called as Signs of a Chemical changes. Like; the formation of a precipitate during chemical reaction is one the best sign which can observe easily. When an ionic compound reacts with other to form insoluble salt, it gets settle down at the bottom of test tube in the form of precipitate. Other signs of chemical-reactions are;

• Color change.
• Liberation or absorption of energy.
• Formation of gas.
• Change in temperature of reacting solution

Let’s perform any Chemical Reaction Experiments and observe sign of reaction.

Take 1-2 ml of a 0.1 M lead (II) nitrate solution in a test tube and add it to 1-2 ml of a 0.1 M potassium iodide solution. When lead nitrate reacts with potassium iodide it form yellow colour precipitate of lead iodide it’s an example of double displacement reaction.

Pb(NO₃)₂ + 2KI  PbI₂ + 2KNO₃

Hence color change and precipitate from colorless reactants can be observed in reaction.

Moment of Inertia Sphere

The moment of inertia of a point mass about a known axis is defined by I = mr²  where m is its mass and r is its perpendicular distance from the axis of rotation.

Introduction :

Definition :  The moment of inertia of a rigid body about an axis is defined as the sum of the products of the masses of different particles, supposed to be constituting the body, and the square of their respective perpendicular distances from the axis of rotation.
                     Moment of inertia of a sphere can be explained in two parts (1) Solid Sphere (2)Hollow Sphere.
(1) Moment of inertia of a Solid Sphere  :  
    (a) About an axis passing through its diameter :   Consider a solid sphere of mass M and radius R. Its moment of inertia about an axis of rotation passing through its diameter is
                                                                            I  =  MR²
   (b) About an axis passing through its tangent  :   Let A'B' the tangent to the solid sphere. A parallel axis through its centre of mass is AB

By parallel axes theorem,
 Moment of inertia about the tangent = Moment of inertia about a diameter + Mr² .
                                                                  =`(2)/(5)` MR² + MR²
                                                         I      =  `(7)/(5)` MR² .

Moment of Inertia Sphere : Hollow Sphere

(2) Moment of Inertia of a Hollow Sphere
(a) Moment of inertia about an axis passing through the diameter of a hollow sphere of mass M and radius R is
                                                I  =`(2)/(3)`   MR² . 
(b)  Moment of inertia about an axis passing through its tangent can be obtained by applying parallel axes theorem. It is given by
                                                  I  =  `(5)/(3)` MR² .

Moment of Inertia Sphere : Example Problem

Problem : If the radius of the earth is suddenly halved keeping its mass constant, find its time period of rotation around its own axis.
Solution :  When the radius of the earth gets reduced suddenly keeping its mass constant, the angular momentum of the earth remains constant.      
                                                I   = constant
     If I changes from I₁ to I₂ ,   changes from`omega` ₁  to`omega`  ₂ so that 
                                          I₁ `omega`₁  =  I₂`omega`₂ .
     Assuming the earth to be a solid sphere, its moment of inertia about its diameter,
                      I  =  MR²
   If the radius changes form R to R/n
                                           `(2)/(5)` MR₁² `omega`₁  =  `(2)/(5)` MR₂² `omega`₂ 
                                                           R²  =  `(2pi)/(24 hours)`  = [R / n]² `(2pi)/(T)`  
          The time period of rotation , T = 24 hours / n² .
      In this problem, the radius changes from  R  to R / 2 .
                         `:.`   `(2)/(5)` MR²  `(2pi)/(24 hours)`   =  `(2)/(5)` M [R/2]² `(2pi)/(T)`
                               T  =  24 / 2²   =  24 / 4  =  6 hours.

Alkaline Metal facts

Introduction :

Alkaline metals are of very keen importance to us. These metals were discovered in the first decade of 19th century by an English chemist Sir Humphry Davy (1778- 829). Along the same time, he also found some elements of other metal families. Alkaline metal facts include all the basic properties shown by them.

About Alkaline Metals
Alkaline metals constituting Group2 of the Periodic Table. These metals show some general properties which are as follows:

• These metals are softer than most other metals
• These metals readily react with water (especially when heated).
• These metals are powerful reducing agents.
• These metals form divalent compounds, etc.

Facts Related to Alkaline Earth Metals

There are various facts related to Alkaline earth metals, some of the important ones are as follows:

• The name alkaline metals owes to their oxides that simply give basic alkaline solutions. These metals melt at high temperature and remain solids in heated atmospheres.
• The alkaline metals show good trend in their properties in the periodic table, with well-defined homologous behavior in going down the group.
• Some alkaline metals like Be and Mg, they show a distinguishable flame color , brick-red for Ca (Calcium) , Magenta-Red for Sr (Strontium) , Green for Ba (Barium) and crimson red for Ra (radium).
• The metals coming in this group show patterns in their electronic configuration, especially the behavior of them in their outermost shells, which results in the trend in chemical behavior.
• The alkaline metals are mostly Silver colored, soft metals, which react readily reactions with halogens.
• Alkaline Metal like Beryllium is highly toxic, it is rarely available to biological systems, and it has no known role in living organisms.
• Other Alkaline metal like Magnesium and calcium are essential to all known living things. They are involved in many roles like in some cellular processes, Mg functions as the active centre of the enzymes and Ca salts takes structural roles.
• Strontium and barium have lower availably in the atmosphere. They play very important roles in marine aquatic life, especially hard corals. These two are also used in medicines. Strontium is used to build the exoskeleton.
• The last metal that is Radium has a low availability and is very highly radioactive.

Conclusion

Alkaline earth metals are of very keen importance to us. These metals are highly important for the automobile industries due to their structure qualities. These metals are of great concern, as they are also included in building machines and other important equipment. 

Nomenclature and Structure of Carboxyl Group

Introduction :

In aldehydes the carbonyl compilation is connection to a carbon and hydrogen as in the ketons is attachment to carbon atoms. The carbonyl combine in to carbonyl acids derived as in combine where carbon is attachment to nitrogen with to halogens are identified amides along with acyl correspondingly. The frequent method of these module combine as aldehyde, ketone.

Nomenclature and Structure of Carboxyl Group Carboxylic Acids:

Aldehydes with ketones as well carboxylic acids are huge increase in plant life along with animal empire. They cooperate an important position in biochemical technique of existence. They append smell by flavour to environment.Carbon compound comprise a carboxyl well-organized locate –COOH are identified carboxylic acids. The carboxyl grouping, consists of a carbonyl grouping append to a hydroxyl group, thus the surname carboxyl. 

Nomenclature and structure Carboxylic acids capacity be aliphatic depending list the collection, alkyl or aryl append toward carboxylic carbon. huge digit of carboxylic acids are ascertain in environment. a number of advanced correlate of aliphatic carboxylic acids identified as greasy acids, happen in usual heavy since ester of glycerol.  Carboxylic acids afford as initial substance for a number of supplementary significant organic complex such similar to anhydrides.
They are develop  in amny foodstuff yield also pharmaceuticals toward include flavours. a number of these people are influence for utilize since solvents to is acetone with for categorize equipment similar to adhesives.

Nomenclature and structure of carboxyl group:
Carboxylic acids are amongst the initial organic compounds to subsist isolated from environment a huge quantity of them are accepted by their frequent names.
The normal given name end with the suffix –ic acid also have derived from latin names of their accepted foundation. intended for naming compounds containing supplementary than one carboxyl group, the finale –e of the alkane is retained.
Structure of carboxyl group:
Nomenclature and structure carboxylic acids the acquaintance to the carboxyl carbon be located in one plane as well as are separated by concerning 120°. The carboxylic carbon is with a reduction of electrophilic than carbonyl carbon as of the feasible resonance structure.

Definition of some Important Terms Pertaining to Coordination Compounds

Introduction:
Complex ion, exciting molecular collective consisting of a metallic atom or ion to which is emotionally involved single or additional electron-donating molecules. In a number of complex ions, such as sulfate, the atoms are so tightly bound collectively that they do something as an only unit. A lot of complex ions however are simply loosely aggregated and lean to distance in a water solution until equilibrium is recognized connecting the complex ion and its important components.

Some Important Terms Pertaining to Coordination Compounds:

Definition of Central atom/ion compounds:

In terms pertaining of coordination entity is definition; the atom/ion to which a fixed number of ions/group is bound in a definite geometrical arrangement around is called the central atoms or ions.
Ligands compounds:
The terms pertaining ions or molecules bound to the central atoms ion in the coordination entity are called ligands. These may be simple ions such as Cl-, Small molecules such as H2o or NH3, larger molecules such as H2NCH2CH2NH2 or N (CH2CH2NH3) or even macromolecules such as proteins.
Definition of coordination number:
Some terms pertaining of synchronization numeral of a metal ion in a complex can be distinct as the number of ligands donor atoms to which the metal is straight bonded.
Definition of coordination sphere:
The central atom/ions and ligands attached to it are enclosed in square, bracket and are collectively terms pertaining as the coordination sphere. Some ionization groups are written outside the bracket and are called counter ions.
Definition of coordination polyhedron:
The spatial arrangements of the important ligand atoms which are directly attached to the central atoms/ion definition terms a coordination polyhedron about the central atoms.
Definition of oxidation number of central atoms compounds:
The oxidation number of the central atom in a some complex is definition as the charge it would carry if all the ligands are removed along with the electron pair that are shared with the central atoms.

Homoleptic and Heteroleptic Complexes Compounds:

         Important complex in which a metal is bound to only one kind of donor group [CO (NH3)6)3+ are known as homoleptic. Important Complex in which a metal is bound to more than one kind of donor group are known as hetroleptic.

Properties of Transverse Waves

Introduction 

A transverse wave is a type of mechanical wave. They travel in a straight line and carry energy and momentum through medium particles from one point to another.
“If on propagation of a mechanical wave through a medium, the medium particles oscillate along a direction perpendicular to the direction of propagation of the wave, the wave is called a transverse wave.”  In other words, if wave travels in x- direction, medium particles vibrate up or down or along y- direction. For example, when one end of a horizontal rope is tied to a hook and the other end is moved up and down, a transverse wave travel horizontally while particles of rope vibrate up and down.
There are several examples of transverse waves in everyday life.               
Vibrations in string, surface water waves, electromagnetic waves, seismic S (secondary) waves, audience wave.

Properties of Transverse Waves

A transverse wave has all properties of mechanical waves.

1. Amplitude- The maximum vertical displacement of the medium particles on either side of its equilibrium position is called the amplitude. It is denoted by ‘a’.
2. Time period- The time taken by medium particle in completing one oscillation is called as the time period of wave.it is denoted by ‘T’.
3. Frequency- The number of oscillations made by a medium particle in 1 second is called as frequency of wave. It is denoted by ‘f’.
4. Phase- The phase of the wave at any instant denotes the position and direction of motion of medium particle at that instant.
5. Wavelength- The distance travelled by the wave in one complete oscillation

is called as wavelength of wave. It is denoted by ‘λ’.

Properties of Transverse Waves : Speed

Wave speed- The distance travelled by the wave in one second is called as ‘wave speed’. It is denoted by ‘v’.
Transverse waves can be formed only in solids because solids have rigidity.
(i)                Speed of transverse wave is given by the following formula-
                              V =√ (η / d)
Where, η is modulus of rigidity of material and d is the density.
(ii)              Speed of transverse waves in flexible stretched string is given by following formula-
                              V = √ (T / m)
 Where T is the tension in the string and m is the mass per unit length of string.