bridge course 13 - kar

Bridge Course 2012‐13

IntroductionChemistry involves three main divisionsdivisionsInorganic chemistryInorganic chemistryPhysical chemistryy yOrganic chemistry

Vikasana Bridge Course 2012

IntroductionOrganic chemistry is B h f h i tBranch of chemistryDeals with Deals with 1. Formation of organic compounds2.Properties of organic compounds


f dFormation of organic compoundsVital force theoryy

Synthesis of urea by Wohler

NH4CNO NH2CONH2Heat

Ammonium Cyanate Urea

Carbon, an essential ingredient, g


CarbonSpecial properties1. Tetravalent 1. Tetravalent 2. Unique catenation propertyI iti f t b h i h i t Imposition of separate branch in chemistry called organic chemistry

f f hDefinition of Organic Chemistry“Organic chemistry is chemistry of

compounds of carbon”Vikasana Bridge Course 2012

ApplicationsFood – carbohydrates, proteins, oils & fats etc

Clothes – cotton, nylon, silk etc

D i di l hit li i tDyes – indigo, malachite, alizarin etc

Fuel – petrol, diesel, kerosene etcFuel petrol, diesel, kerosene etc

Petrochemicals – Polymers, pesticides,

detergents, cosmetics etcVikasana Bridge Course 2012

Applications continued..Chemotherapy – use of drugs (chemical

substances) against the diseases without

causing harmful side effects to the host g

tissues.


Applications continued..Drugs:

Antiseptic – dettol, salolAntiseptic dettol, salolAnalgesic – apririn, disprinA ti ti t l iAntipyretic ‐ paracetamol , crocinAntibiotic – penicillin, ampicillinAntimalarial – choloroquin, quinineTranquilizer – morphine, barbituric acida qu e o p e, ba b tu c ac d


Functional GroupsAn atom or group of atoms that determines properties of organic compounds. E lExamples:

Structure Compound Functional group

H Methyl alcohol ‐OH : alcohol H – C – O – H

H


Functional Groups contd..Structure Compound Functional grpStructure Compound Functional grp

H OH – C – C – O –H

Acetic acid ‐ COOH: Carboxylic acid H – C – C – O –H Carboxylic acid

H H Acetaldehyde ‐ CHO; HH H

H – C – C = O H

Acetaldehyde CHO; aldehyde

HH

H – C – ClMethylchloride ‐ Cl : chloro

HVikasana Bridge Course 2012

Homologous SeriesSeries of closely related organic compounds with Series of closely related organic compounds with similar chemical propertiesCharacteristicsC a acte st cs1. These series are represented by General

formula2. Two successive member of series differ by ‐

CH2. 2

3. They are prepared by common methods4 Show a regular gradation in physical 4. Show a regular gradation in physical

properties. Vikasana Bridge Course 2012

Homologous Series continued..Alkane seriesName Molecular

F l

Alkane series

Name Molecular

FormulaMethane CH4Eth C H

Alkene series

FormulaEthene C2H4

Ethane C2H6Propane C3H8B t C H 2 4

Propene C3H6Butene C4H8

Butane C4H10

4 8Pentene C5H10


Homologous Series continued..

Name MolecularAlcohol seriesName Molecular

FormulaMethanol CH OHMethanol CH3OHEthano C2H5OHPropanol C H OHPropanol C3H7OHButanol C4H9OH


Composition of organic compoundsp g pDeals with constituent of organic compounds in qualitative and quantitative formsin qualitative and quantitative formsQualitative analysis:D t ti f l t t i i Detection of elements present in organic compound

lQuantitative analysis:Estimation of elements present in organic compound and expressing it in percentage form Vikasana Bridge Course 2012

Chemical FormulaR i f l l f b Representation of a molecule of a substance in terms of symbols of various elementsExample:

Chemical formula of water – H2OChemical formula of carbon dioxide – CO2

Chemical formula of glucose – C6H12O6g 6 12 6

Two types Empirical formulaEmpirical formulaMolecular formula


Empirical FormulaSimplest formula

Gives the ratio of number of atoms of

various elements present in one molecule of various elements present in one molecule of

the compound

Obtained from percentage of various

l t t i th delements present in the compoundVikasana Bridge Course 2012

Empirical Formula Examples

Compound Emperical formula

Hydrogen peroxide HOy g p

Glucose CH2O

Benzene CH

Napthalene C5H4Napthalene C5H4

Ethene CH2

Ethane CH3


Molecular FormulaTrue (Actual) formula

Gives actual number of atoms of various

elements present in one molecule of the elements present in one molecule of the

compoundp

Obtained knowing empirical formula and

molecular massVikasana Bridge Course 2012

Molecular Formula Examples

d l l f lCompound Molecular formula

Hydrogen peroxide H2O2y g p 2 2

Glucose C6 H12 O6

Benzene C6 H6

Napthalene C10 H8Napt a e e C10 8

Ethene C2H4

Ethane C2H6


Relation between Empirical & Molecular Formula

Molecular formula = (Empirical formula) nWhere ‘n’ is simple whole number and is given by,

Molecular massE i i l f l n = Empirical formula mass

Thi l i h l i d i i f l l

n

This relation helps in determination of molecular formula Vikasana Bridge Course 2012

Determination of Molecular Formula knowing molecular mass & empirical formulaExample (1): Example (1): Molecular mass of acetylene is 26, Empirical formula of acetylene is CH Empirical formula of acetylene is CH, ∴Empirical formula mass is 13.

26∴n = = 22613

∴molecular formula of acetylene = (CH)2 = C2H2Vikasana Bridge Course 2012

Determination of Molecular Formula

Example (2):

Determination of Molecular Formula knowing molecular mass & empirical formulaExample (2): Molecular mass of Glucose is 180Empirical formula is CH OEmpirical formula is CH2O∴ Empirical formula mass is 30∴n 6180∴n = = 6

l l f l f Gl (CH O)

30

∴molecular formula of Glucose = (CH2O)6 = C6H12O6 Vikasana Bridge Course 2012

bridge course 13 - kar

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