Functional Group and its importance

Functional Group:

Defination:

An atom or group of atom in a molecule that is responsable for its specific chemical properties.

Example: For example in Alcohol (R-OH) Hydroxyl (OH) is functional group.

Importance:

Functional groups are very important in organic chemistry.

1. Functional group is a site of reaction.

2. It is base for nomenclature.

3. It is base for classification.

polyfunctional:

Compound containig more then one functional group is called polyfunctional.For Example:

CH2=CH-OH (Vinyl alcohol)

This compound contain 2 functional groups one alcohol and second alkene.

Alkane :It contain C-C and C-H singal bond.

Examples:

Methane   CH4 

Ethane      CH3-CH3

Alkene: It is type of hydrocarbon thatcontain carbon carbon double bond (C=C). 

Examples:

Ethene   CH2=CH2

Propene CH3-CH=CH2

Alkyne: It is type of hydrocarbon that contain carbon carbon Triple bond.

Examples:

Ethyne    H-C≡C-H

Propyne CH3-C≡C-H

Alkyl Halide: In alkyl halide hydrogen of alkane is replaced by halogen (F,Cl,Br,I).

Examples:

CH4 =Methane 

CH3- =Methyl 

CH3-Cl Mehyl Chloride or Chloromethane.

Alcohol:(R-OH):

In alcohol hydrogen of alkane is replaced by hydroxyl OH group.

Examples:

CH3-OH Methyl Alcohol or Methanol

C2H5-OH  Ethyl alcohol or Ethanol

Carobonyl componds: (  ---C==O  )                                                                     |

i.Aldehyde: It has Hydrogen on one side of carbonyl group.

Examples: 

H--C==O                                                                          !                   Fomldehyde   (Methanal)               H                                                                                                                                                                  CH3--C==O                                                                          !            Acetaldehyde   (ethanal)                      H

ii.Ketone: 

It has Carbon on both side of carbonyl group

Examples:

CH3--C==O                                                                         !                                                                                CH3    Acetone(propanone)

Carboxylic acid:(R-COOH)

It contain carboxylic group ( -COOH)

Examples:

HCOOH Formic acid or methanoic acid

CH₃COOH, Ethanoic acid acetic acid

CH₃CH₂COOH, Propanoic acid

           

Ligand and Its types

 Ligand : 

ligand is atom or group of atom Which can donate electron pair .

Or species which can donate lone pair.

Types of ligand:

It has following types.

Monodentate ligand :

It is type of ligand which can donate one electron pair.

Example:Cl -, I- ,OH - ,NH3, CO

Bidentate ligand :

It is type of ligand which can donate two electron pairs.

Example:NH2NH2,sSulphate ion carbonate ion

Tridentate ligand :

It is type of ligand which can donate Three electron pairs..

Example:Diethylene triamine

Hexadentate ligand :

It is type of ligand which can donate six electron pairs.

Example:Ethylene diaminetetra acetate(EDTA).

Differences between nuclear fission and nuclear fusion

 Nuclear Fission:

1- Heavy nuclei split into lighter nuclei of comparable atomic masses

2- nuclei of heavy elements undergo fission

3- The reaction initiates at normal temperature

4- The fission process liberates about 200 MeV energy

5- Fast neutrons are also released

6- Fuel is either solid or liquid .

Nuclear fusion:

1- lighter nuclei fuse to form heavy nuclei.

2- nuclei of light elements are in involved in       the process of fusion.

3- Fusion initiates at 10^8 K.

4- The energy released in 24 MeV.

5- nature of the ejected particles depends uopn the type of thermonuclear reaction.

6- Fuel is in plasma state.

Rules for Nomenclature and Alkynes:

 ALKYNES:

Alkynes are unsaturated hydrocarbons which contain a carbon-carbon triple bond. 

They can be represented by the general formula CnH2n-2. 

The first and most important member of this series is acetylene and hence these are generally called acetylenes. 

The carbon-carbon triple bond is therefore called acetylenic bond.

Rules for Nomenclature and Alkynes: ( IUPAC)

   Following are the some rules 

1. Select  longest continuous chain of carbon          atom containing triple bond.

2. Name of compound must end on yne .

      E.g ethyne propyne etc

3.Give triple bond  least possible number.

4.Substiutnt name is always written before              parent name.

5.Position of triple bond must be mentioned.

6.Position of substituent must be mentioned         before name

7.If more then one similar type of substituents are present we will use the term di For 2 Tri for 3

 Tetra  for 4

8.If different type of substituents are present we  will follow alphabatical order .

9.If more then one triple bonds are present we will use the term diyne for 2triple bonds and triyne for 3 triple bonds.

Examples:

H-C≡C-H                Ethyne 

H–C≡C-CH3          Propyne

CH3-CH2-CH2-C≡C-CH3  2-Hexyne

H-C≡C-CH2-CH2-CH2-CH2-CH3 1-Heptyne

H-C≡C-C≡C-H 1,3-Butadiyne

Rules for Nomenclature and Alkenes: ( IUPAC)

 ALKENES:

Alkenes are unsaturated hydrocarbons which contain a carbon-carbon double bond. 

They can be represented by the general formula CnH2n. 

Why alkenes are called olefins?

They are also known as 'olefins', derived from Latin word 'oleum' meaning 'oil' and 'ficare' meaning 'to form', because their lower members form oily layer on treatment with chlorine and bromine.

Rules for Nomenclature and Alkenes: ( IUPAC)

Following are the some rules 

1. Select  longest continuous chain of carbon          atom as a parent chain containing double bond.

2. Name of compound must end on ene .

      E.g ethene propene etc

3.Give double bond  least possible number.

4.Substiutnt name is always written before              parent name.

5.Position of double bond must be mentioned.

6.Position of substituent must be mentioned         before name

7.If more then one similar type of substituents are present we will use the term di For 2 Tri for 3

 Tetra  for 4

8.If different type of substituents are present          we  will follow alphabatical order .

9.If more then one double bonds are present we will use the term diene for 2 double bonds and triene for 3 double bonds

Examples      

            1      2      3      4     5     6                                         CH3-CH=CH-CH2-CH2-CH3  2- Hexene

                 CH3                                                                               |                                                                    CH3-CH=C-CH-CH2-CH3 

          3-Methyl-2-Hexene

 1      2      3      4     5     6

CH3-CH=CH-CH=CH-CH3  2,4-Hexadiene

Rules of Nomenclature and Alkanes

  

Hydrocarbon:

It is type of saturated hydrocarbon containing carbon -carbon single bond .

ALKANES:

Alkanes are open chain saturated hydrocarbons containing single bond. 

which can be represented by the general formula CnH2n+2 (where'n'is the number of carbon atoms),

while cyclo alkanes are cyclic saturated hydrocarbons represented by the general formula CnH2n . 

It is to be noted from the general formula of cycloalkanes, that there are two hydrogen atoms less than the corresponding alkanes. 

In cycloalkanes, two carbon atoms of the molecule utilize one of their valency in forming bonds with other carbon atoms for formation of cyclic ring.

Following are the some rules 

Rules for Nomenclature and Alkanes: ( IUPAC)

Following are the some rules 

1. Select  longest continuous chain of carbon          atom as a parent chain.

2. Name of compound must end on ane .

E.g methane ethane propane etc

3.Give substituent least possible number.

4.Substiutnt name is always written before              parent name.

5.Position of substituent must be mentioned.

 6.If more then one similar type of substituents are present we will use the term di For 2 Tri for 3

Tetra  for 4

7.If different type of substituents are present we will follow alphabatical order .

Examples:

                   CH3                                                                               |                                                              CH3-CH2-CH-CH2-CH2-CH3  3-Methyl hexane

                                 CH3  CH3                                                                   |     |                                                                CH3-CH-CH-CH2-CH2-CH3 

          2,3-Dimethyl hexane

CHELATING LIGANDS

 CHELATING LIGANDS:

"The bonding of a polypeptide ligand to a metal ion through more than one site is called chelating ligand."

These ligands produce a ring like structure called chelate. 

The polydentate ligand is called a chelating agent, 

The process of chelate formation is known as chelation and the compounds formed are called as chelate compounds. 

Chelation increases the stability of complex. For example, ethylene diamine acts as a bidentate chelating ligand.

HOMOLOGOUS SERIES:

 HOMOLOGOUS SERIES:

"A series of organic compound in which each member is different from the next member by a methylene (-CH2-) group is called homologous series".

All the members that differ from each other by methylene group, are called homologues. Each class of organic compounds has its own homologous series which can be represented by a general formula. For example, alkanes (saturated hydrocarbons) can be represented by a series of compounds. It can be represented by a general formula CnH2n+2 where 'n' shows the number of carbon atoms in the corresponding alkane.

As it is clear from alkane homologous series that each member is different from the adjacent member by CH3. Similarly, this series can be expanded beyond C10 to higher alkanes. Similar homologous series can be developed for alkenes, alkynes, alcohols, ethers, amines, carboxylic acids, carbonyl compounds etc.

CHARACTERISTICS OF HOMOLOGOUS SERIES:

*Each class of organic compounds has its own homologous series having same  general formula.

*All the members of homologous series have similar chemical properties.

* They have same general methods of preparation similar structural features.

*They have same functional group.

*The physical properties like melting point, boiling point, densities etc, increase down the series due to increase in their molecular masses.

For Example lets see homology in alcohol.

CH3CH2OH                               Ehtyl alcohol

CH3CH2CH2OH                        Propyl alcohol

CH3CH2CH2CH2OH                 Butyl alcohol 

CH3CH2CH2CH2CH2OH          Pentyl Alcohol

CH3CH2CH2CH2CH2CH2OH  Hexyl alcohol

Consider another example:

CH3CH2Cl                               Ehtyl Chloride

CH3CH2CH2Cl                  Propyl Chloride

CH3CH2CH2CH2Cl              Butyl Chloride

CH3CH2CH2CH2CH2Cl        Pentyl Chloride

CH3CH2CH2CH2CH2CH2Cl  Hexyl Chloride

NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY

NUCLEAR MAGNETIC RESONANCE (NMR) SPECTROSCOPY:

Nuclear magnetic resonance spectroscopy (NMR) is the most powerful tool available for organic structure determination. Like infrared spectroscopy, NMR can be used with a very small amount of sample, and it doesn't harm the sample. The NMR spectrum provides a great deal of information about the structure of the compound, and many structures can be determined using only the NMR spectrum. More commonly, however, NMR spectroscopy is used in conjunction with other forms of spectroscopy and chemical analysis to determine the structures of complicated organic molecules

MAGNETIC SHIELDING BY ELECTRONS:

Protons in a molecule are surrounded by electrons and exist in slightly different electronic (magnetic) environments from one another. The electron densities vary from one proton to another. Thus, the net field felt by a proton in a molecule will always be less than the applied field and the proton is said to be shielded. All of the protons of a molecule are shielded from the applied field by the electrons, but some are less shielded than others, because they may have less surrounding electron cloud and termed as deshielded protons. Deshielded protons are generally in vicinity of electronegative atoms in a molecule. More shielded protons absorb low radio-frequency radiations and their signals appear to the right side of spectrum, upfield region; while deshielded protons absorb high radio-frequency radiations and their signals therefore, appear at the left side of spectrum, downfield region.

PESTICIDES:

 PESTICIDES:

Pests harm crops and transmit diseases both to human and animals. Pesticides are the substances that can directly kill an unwanted organism or otherwise control by interfering with its reproduction process. The current ability to produce large amounts of food on relatively small amount of land had been made possible around the world by use of pesticides. At present more than ten thousand different types of synthetic organic pesticides have been formulated. They are broadly classified into several principal types according to their general chemical nature. The most important and widely used pesticides are insecticides (which kill insects), herbicides (which kill undesired plants) and fungicides (which control the growth of fungus on the plant).

The use of various pesticides also helped in the eradication of diseases such as malaria, yellow fever, bubionic plague and sleeping sickness.

Wide spread use of pesticides for getting greater crop yields if not properly checked and controlled has associated risks of contaminating the soil, plants and the water. The drainage water from the agricultural land mostly contains pesticides. Therefore if the use of any type of pesticide is not properly controlled it enters through various roots i.e., agricultural food products and drinking water into the food chain and thus pose serious health problems to both human beings and animals.

USES OF PVC and Nylon

 •USES OF PVC:

PVC or polyvinyl chloride, is a type of plastic used in numerous industries. It is durable, inexpensive and resistant to heat, water and chemicals.

*PVC plastic is manipulated to create a leather-like material called Rexine.

*PVC are used for pipes. These pipes are strong, light weight and less reactive.

*PVC plastic is used to form the insulating material on electrical wires.

*PVC is used to manufacture bottles.

* Other uses of PVC include medical tubing, PVC window frames, flexible packaging, blood bags, resilient flooring, vinyl paneling, drainage pipes, gramophones records, carpet backing, etc.

• USES OF NYLON:

Nylon is a versatile and incredibly useful material.

*Stockings_nylons strong fibres can be woven together to produce a lightweight silky fibre that is perfect for stockings.

*Parachutes-nylon is used in the manufacture of parachutes.

*Tents and camping equipment_ durability and resistance make nylon a great choice for all kinds of camping equipments.

*Boating and sailing_ nylon is used in the production of many sails and ropes.

*Nylon is used in moulded machine parts such as gears and bearings.

Lipstic and its composition

 LIPSTICK:

Lipstick are basically dispersions of colouring matter in a base containing a suitable blend of oils, fats and waxes suitably perfumed, flavoured and moulded in the form of stick and enclosed in a case. Some lipsticks are also lip balm, to add colour and hydration.

•CHEMICAL COMPOSITION OF LIPSTICKS:

The chemical composition of lipstick varies greatly. The general composition of lipsticks are;

*A mixture of non volatile oils,e.g. caster, vegetable, mineral or wool fat, lanolin oil.

*Mixture of waxes, e.g. bee wnax or carnauba.

* Colours

*Antioxidants

*Preservatives

Usually perfumes are also added in very small quantity to combat the unpleasant fatty odour of the oil. 

The oil makes the wax-based product soft and to be easily applied.

 In order to reduce the 'stickness', usually, esters of fatty acids (like 2-propyl myristate) is also added. 

Lipsticks are made from hydrophobic materials.

 The dyes are water_insoluble. 

Water soluble dyes such as green or blue food dyes can be used to provide lipstick colouration but they are, first combined with metal oxides such as aluminium hydroxide,Al(OH)3, to form an insoluble precipitate 

It is then suspended in the oil base of the lipstick.

 

Colour is a key ingredient of lipsticks.

 Silicones and oily material are also added to reflect light and provide shine.

Measurement of viscosity:

General principle:

     The measurement of viscosity of liquid is based on pioseulle's equation.

               n=πPtr^4/8VI

Where:

   V= volume of liquid

    r= radius of capillary tube

    l= length of tube

   P= pressure applied

Measurement of absolute viscosity:

 It is difficult to measure  directly the exact value of absolute viscosity because measurement of p,r and v is difficult.

So the viscosities of liquids are expressed in relative term

relative viscosity:

          "This is the ratio of viscosity of liquid to the viscosity of water taken as reference standard and this is called relative viscosity.

OSTWALD's VISCOMETER (measurment of relative viscosity):

It is used to measure the relative viscosity.

• It is a U- shaped glass tube with two marks 'x'&'y'.

•It has two bulbs 'A' and 'B'.

•The bulb A is at higher level than B.

•A definite volume of liquid is put in bulb B and then sucked in bulb A.

•The time of flow of liquid is noted .Similarly the time of flow of reference liquid water is also noted.

•Density of liquid is determined by "Specific gravity bottle".

•Follow8ng equation is applied to calculate Viscosity.

       n°/n= d°/d × t°/t

Where:

n°= viscosity of liquid

 n= viscosity of relative liquid

d°= density of liquid determined by Specific gravity bottle

d=density of reference liquid

t°=time of flow of liquid

t= time of flow of reference liquid

Viscosity and fludity

Defination:

    "Liquid's resistance to flow".

                      OR

    " The frictional effect between different layers of a flowing fluid ".

Explanation:

It is the property which opposes the relative motion of adjacent layers of liquid. 

The substances that cannot flow easily have large coefficient of viscosity. (such as honey)whereas the substances that can flow easily have small coefficient of viscosity (Such as water).

Factors:

It depends upon: 

•The strength of Intermolecular force 

•Structure of the compound

•Shape of the molecule

The force which is required to maintain the steady flow of liquid in direction of the force is directly proportional to the viscosity gradient which is normal to the direction of flow. 

Defination:

   "It is the force per unit area , needed to maintain unit difference of velocity between two parallel layers of the liquid , unit distance apart." 

Unit of viscosity "poise":

"When  a force of one dyne per square cm is maintained, between two layers which are 1cm apart and the difference of velocity between the two layers is 1cm per second, then it is called poise. "

           1poise =10^-1 kg m^-1 s^-1

            1 centipoise =10^-2 poise

            1 millipoise =10^-3 poise

Effect of temperature on viscosity:

   The viscosity of a liquid falls with the increase in temperature.

It is estimated that for each one degree rise of temperature, there is 2% decrease of viscosity.

Fluidity:

       " Fluidity is the reciprocal of viscosity".

The units of fluidity are reciprocal of viscosity.(poise^-1).

Metallurgy of copper

 *~Metallurgy of copper..~*

Occurrence 

(a) sulphide ores ..

Copper pyrite or chalcopyrite 

Copper glance or chalcocite

Bornite or peacock ore

(b) oxide ores..

Cuprite 

Malachite

Melaconite

Native copper crystallizes in the cubic system .In Pakistan copper ores are found in north waziristan agency, chitral state.. etc

Extraction of copper from sulphite ores:

Large amount of copper 75% are obtained from copper pyrite by smelting . Ores containing 4% or more of copper are treated by smelting process.

1- smelting 

In this process the concentrated sulphide ores is oxidized by air . Sulphur burns to so2 , iron is converted to FeO which is removed as Fesio3.. following steps are involved

(a) concentration 

The finely crushed ore is concentrated by froth flotation process .The finely ground ore is suspended in water containing a little pine oil . A blast of air is passes through the suspension .

(b) Roasting

The concentrated ore is then roasted in a furnace in presense of ac current of air . Sulphur is oxidized to so2 and the impurities of arsenous and antimony are removed as volatile oxide .

(c) smelting 

The ore is now transferred into a water blast furnace . A little coke and sans are also added . The furnace is provided at the base with a row of twyers for the supply of air . The combustion of Orr itself provides a lot of heat and there fore less amount of coke are usually needed .

The iron and other silicates rise to the top and are removed as slav . A mixture of Cu2S and some unreacted Fess forms the lower layer and is called matte.

(d) Bessemerization 

The matte is removed in a Bessemer converter by blowing the air through the molten material. Fess is first oxidized to FeO and So 2 . Sand is added to remove FeO as FeSiO3 . The blast of air converts to metallic copper.

The copper obtained through Bessemerization has characteristics appearance due to evolution of gases from within and is called blister copper . Blister copper is about 98% pure copper .

2- Hydrometallurgical process..

The low grade sulphite ores of copper are subjected to Hydrometallurgical process . The crushed ore is bulk is allowed to whether in contact with water . Water is also allowed to percolate from the top . After about one year copper sulphide is oxidized to CuSO4 . At the same time FeSO4 and H2SO4 are also formed .

Uses:

1- copper is extensively used in preparing water stills , vaccum pans, steam coils , etc

2- copper is used in electrical equipment due to its high electrical conductivity.

3- large quantities of copper are used for the fireboxes of locomotive boilers. 

4- copper forms a large number of usesful alloys, brass, bronze, Monel metal German silver etc..

APPLICATIONS OF HYDROGEN BONDING

 APPLICATIONS OF HYDROGEN BONDING:

•Thermodynamic properties:

Hydrides of group 4 have lower points than that of group 5,6 and 7 because these hydrides are non polar and have only London dispersion forces among their molecules while group 5A,6A,and 7A have polar molecules which have dipole dipole forces.

•Solubility of hydrogen bonded molecules:

The compounds that have hydrogen bonds are soluble in each other. Ethyl alcohol and low mass carboxylic Acids can dissolve in water because of hydrogen bonds. Oil is insoluble because of no attraction.

• Cleansing action:

Soaps and detergents perform the cleansing action. Their polar parts are water soluble due to hydrogen bonding and non polar part dissolve oil or grease. Attraction between water and polar end of soap molecule carries the oil or grease droplet into the water.

• Hydrogen bonding in paints and dyes:

Paints and dyes have adhesive action due to hydrogen bonding. Similarly hydrogen bonding also makes glue and honey sticky substances.

• Clothing:

The rigidity and tensile strength of the cotton, silk and synthetic fibres are due to hydrogen bonding. Hydrogen bonding is of great importance in thread making materials.

• Food materials:

Food materials like carbohydrates consists of glucose, fructose, sucrose, each of them contains -OH groups which are responsible for hydrogen bonding in them.

HYDROGEN BONDING:

 HYDROGEN BONDING:

•Definition:

Hydrogen bond is the attraction between the lone pair of an electronegative atom and a hydrogen atom that is bonded to N,O,or F.

• Example:

Hydrogen bonding is present in NH3, H2O, HF, alcohols and carboxylic acids etc.

• Explanation:

Which one of them have higher boiling point.H2O OR H2S?

The boiling point and heat of vapourization of water are higher than those of H2S because H2O molecules attract each other through H-bonding whereas H2S molecules attract each other by dipole-dipole interactions.

• Limitation:

Hydrogen bonding is mainly limited to participation of nitrogen, oxygen and flourine atom.

• Strength of hydrogen bond:

Hydrogen bonds are stronger than London dispersion forces. Increasing order of strength of attractive forces is;

London dispersion force<dipole-dipole<H-bonding<Covalent bond.