chemistry introduction

33
CHEMISTRY CHEMISTRY CHEMISTRY IS THE SCIENCE THAT CHEMISTRY IS THE SCIENCE THAT DESCRIBES MATTER. ITS CHEMICAL DESCRIBES MATTER. ITS CHEMICAL AND PHYSICAL PROPERTIES, THE AND PHYSICAL PROPERTIES, THE CHEMICAL AND PHYSICAL CHANGES CHEMICAL AND PHYSICAL CHANGES MATTER UNDERGOES. AND ENERGY MATTER UNDERGOES. AND ENERGY CHANGES THAT ACCOMPANY THESE CHANGES THAT ACCOMPANY THESE PROCESSES PROCESSES MATTER ANY THING WHICH OCCUPIES MATTER ANY THING WHICH OCCUPIES SPACE AND HAVING WEIGHT IS CALLED SPACE AND HAVING WEIGHT IS CALLED MATTER. MATTER.

Upload: muneeb5000001

Post on 09-Aug-2015

59 views

Category:

Education


1 download

TRANSCRIPT

CHEMISTRY CHEMISTRY

CHEMISTRY IS THE SCIENCE THAT CHEMISTRY IS THE SCIENCE THAT DESCRIBES MATTER. ITS CHEMICAL DESCRIBES MATTER. ITS CHEMICAL AND PHYSICAL PROPERTIES, THE AND PHYSICAL PROPERTIES, THE CHEMICAL AND PHYSICAL CHANGES CHEMICAL AND PHYSICAL CHANGES MATTER UNDERGOES. AND ENERGY MATTER UNDERGOES. AND ENERGY CHANGES THAT ACCOMPANY THESE CHANGES THAT ACCOMPANY THESE PROCESSESPROCESSES

MATTER ANY THING WHICH OCCUPIES MATTER ANY THING WHICH OCCUPIES SPACE AND HAVING WEIGHT IS SPACE AND HAVING WEIGHT IS CALLED MATTER.CALLED MATTER.

CHEMICAL PROPERTIESCHEMICAL PROPERTIESCHEMICAL PROPERTIES ARE PROPERTIES CHEMICAL PROPERTIES ARE PROPERTIES THAT MATTER EXHIBITS AS IT THAT MATTER EXHIBITS AS IT UNDERGOES CHANGES IN COMPOSITIONUNDERGOES CHANGES IN COMPOSITION

PHYSICAL PROPERTIESPHYSICAL PROPERTIESPHYSICAL PROPERTIES WHICH CAN BE PHYSICAL PROPERTIES WHICH CAN BE OBSERVED IN THE ABSENCE OF ANY OBSERVED IN THE ABSENCE OF ANY CHANGE IN COMPOSITIONCHANGE IN COMPOSITION

CHEMICAL CHANGE PHYSICAL CHEMICAL CHANGE PHYSICAL CHANGECHANGE

• ONE OR MORE ONE OR MORE SUBSTANCES ARE SUBSTANCES ARE CONSUMEDCONSUMED

• ONE OR MORE NEW ONE OR MORE NEW SUBSTANCES ARE FORMEDSUBSTANCES ARE FORMED

• CHANGE IN COMPOSITION CHANGE IN COMPOSITION OCCURS.OCCURS.

• ENERGY CHANGES THAT ENERGY CHANGES THAT ACCOMPANY THE ACCOMPANY THE CHEMICAL PROCESSCHEMICAL PROCESS

NON OF THESENON OF THESE

BRANCHES OF CHEMISTRYBRANCHES OF CHEMISTRY

• ORGANIC CHEMISTRYORGANIC CHEMISTRY

• INORGANIC CHEMISTRYINORGANIC CHEMISTRY

• ANALYTICAL CHEMISTRYANALYTICAL CHEMISTRY

• PHYSICAL CHEMISTRYPHYSICAL CHEMISTRY

• BIO-CHEMISTRYBIO-CHEMISTRY

(09-05-2012 Evening)(09-05-2012 Evening)

ORGANIC CHEMISTRY

Organic chemistry is a discipline within Organic chemistry is a discipline within chemistry which involves the scientific chemistry which involves the scientific study of the structure, properties, study of the structure, properties, composition, reactions, and preparation composition, reactions, and preparation (by synthesis or by other means) of (by synthesis or by other means) of chemical compounds that contain chemical compounds that contain carbon. These compounds may contain carbon. These compounds may contain any number of other elements, including any number of other elements, including hydrogen, nitrogen, oxygen, the hydrogen, nitrogen, oxygen, the halogens as well as phosphorus, silicon halogens as well as phosphorus, silicon and sulfur. and sulfur.

INORGANIC CHEMISTRYINORGANIC CHEMISTRY

Inorganic chemistry is the branch of Inorganic chemistry is the branch of Chemistry concerned with the properties Chemistry concerned with the properties and behavior of inorganic compounds. and behavior of inorganic compounds. This field covers all chemical This field covers all chemical compounds except the organic/myriad compounds except the organic/myriad compounds (compounds containing C-H compounds (compounds containing C-H bonds), which are the subjects of bonds), which are the subjects of organic chemistry. organic chemistry.

ANALYTICAL CHEMISTRYANALYTICAL CHEMISTRYAnalytical chemistry is the study of the Analytical chemistry is the study of the chemical composition of natural and chemical composition of natural and artificial materials. Properties studied in artificial materials. Properties studied in analytical chemistry include geometric analytical chemistry include geometric features as well as features such as features as well as features such as composition and species identity. Unlike composition and species identity. Unlike the sub disciplines inorganic chemistry the sub disciplines inorganic chemistry and organic chemistry, analytical and organic chemistry, analytical chemistry is not restricted to any chemistry is not restricted to any particular type of chemical compound or particular type of chemical compound or reaction. reaction.

PHYSICAL CHEMISTRYPHYSICAL CHEMISTRYPhysical chemistry (also called physico chemistry) Physical chemistry (also called physico chemistry) is the explanation of macroscopic, microscopic, is the explanation of macroscopic, microscopic, atomic, subatomic, and particulate phenomena in atomic, subatomic, and particulate phenomena in chemical systems in terms of physical concepts; chemical systems in terms of physical concepts; sometimes using the principles, practices and sometimes using the principles, practices and concepts of physics like thermodynamics, concepts of physics like thermodynamics, quantum chemistry, statistical mechanics and quantum chemistry, statistical mechanics and dynamics.dynamics.

BIO CHEMISTRYBIO CHEMISTRY

BiochemistryBiochemistry is the study of the chemical is the study of the chemical processes in living organisms. It deals with the processes in living organisms. It deals with the structure and function of cellular components structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules.acids and other biomolecules.

CLASIFICATION ACCORDING TO CLASIFICATION ACCORDING TO THE PROFESSIONTHE PROFESSION

• PHARMACEUTICAL CHEMISTRYPHARMACEUTICAL CHEMISTRY• CLINICAL CHEMISTRYCLINICAL CHEMISTRY• POLYMER CHEMISTRYPOLYMER CHEMISTRY• ENVIRONMENTAL CHEMISTRYENVIRONMENTAL CHEMISTRY• AGRICULTURAL CHEMISTRYAGRICULTURAL CHEMISTRY• SOIL CHEMISTRYSOIL CHEMISTRY• NUCLEAR CHEMISTRYNUCLEAR CHEMISTRY• CHEMICAL ENGINEERINGCHEMICAL ENGINEERING

SUBSTANCESSUBSTANCESA pure substances is any kind of matter, A pure substances is any kind of matter, all samples of which have identical all samples of which have identical composition and under identical composition and under identical conditions has identical properties.conditions has identical properties.

ISTOPESISTOPES• ISOTOPES are atoms of the same elements ISOTOPES are atoms of the same elements

containing different numbers of neutrons in their containing different numbers of neutrons in their nuclei.nuclei.

• IsotopesIsotopes are different types of atoms (nuclides) of are different types of atoms (nuclides) of the same chemical element, each having a the same chemical element, each having a different number of neutrons. Correspondingly, different number of neutrons. Correspondingly, isotopes differ in mass number (or number of isotopes differ in mass number (or number of nucleons) but not in atomic number.nucleons) but not in atomic number.

• The number of protons (the atomic number) is the The number of protons (the atomic number) is the same because that is what characterizes a same because that is what characterizes a chemical element. For example, carbon-12, chemical element. For example, carbon-12, carbon-13 and carbon-14 are three isotopes of the carbon-13 and carbon-14 are three isotopes of the element carbon with mass numbers 12, 13 and 14, element carbon with mass numbers 12, 13 and 14, respectively. The atomic number of carbon is 6, so respectively. The atomic number of carbon is 6, so the neutron numbers in these isotopes of carbon the neutron numbers in these isotopes of carbon are therefore 12−6 = 6, 13−6 = 7, and 14–6 = 8, are therefore 12−6 = 6, 13−6 = 7, and 14–6 = 8, respectively. date 9-5-12respectively. date 9-5-12

COMPOUNDSCOMPOUNDS

• Compounds are pure substance Compounds are pure substance consisting of two or more different consisting of two or more different elements in a fixed ratioelements in a fixed ratio

MIXTURESMIXTURES• Mixtures are combination of two or more Mixtures are combination of two or more

substances in which each substance substances in which each substance retains its own composition and retains its own composition and properties.properties.

• The composition of mixtures can be varied The composition of mixtures can be varied widely.widely.

• In chemistry, a In chemistry, a mixturemixture is when two or is when two or more different substances are mixed more different substances are mixed together but not combined chemically. together but not combined chemically.

• The molecules of two or more different The molecules of two or more different substances are mixed in the form of substances are mixed in the form of solutions, suspensions, and colloids. solutions, suspensions, and colloids.

HOMOGENEOUS HOMOGENEOUS HETEROGENEOUSHETEROGENEOUS

• Mixtures can be classified as Mixtures can be classified as homogeneous or heterogeneous.homogeneous or heterogeneous.

• HOMOGENEOUS MIXTURE, also called a HOMOGENEOUS MIXTURE, also called a solution, has uniform composition and solution, has uniform composition and properties throughout mixture.properties throughout mixture.

ATOMSATOMSAn atom is the smallest particle of an An atom is the smallest particle of an element. Historically an atom has been element. Historically an atom has been defined as the smallest particle of an defined as the smallest particle of an element that can enter into a chemical element that can enter into a chemical combination.combination.

MOLECULEMOLECULEMolecule is the smallest particle of an Molecule is the smallest particle of an element or compound that can have a element or compound that can have a stable independent existence.stable independent existence.

AVOGADRO’S NUMBERAVOGADRO’S NUMBERAvogadro’s Number for any element, A Avogadro’s Number for any element, A Mass in grams numerically equal to its Mass in grams numerically equal to its atomic mass contains the same no of atomic mass contains the same no of atoms,=6.02xatoms,=6.02x1023

this number is Avogadro's number.this number is Avogadro's number.

MOLEMOLEAvogadro’s number = Mole (atomic or Avogadro’s number = Mole (atomic or molecular molecular weight weight expressed in GMS.expressed in GMS.

Avogadro number connects Avogadro number connects masses with number of atoms. It masses with number of atoms. It enable us to define a convenient unit enable us to define a convenient unit for dealing quantitatively with what for dealing quantitatively with what takes place in chemical reaction.takes place in chemical reaction.

AN IONSAN IONS

An ion is an atom or group of An ion is an atom or group of atoms that carries an electrical atoms that carries an electrical charge. charge.

THE LAW OF CONSERVATION OF THE LAW OF CONSERVATION OF MATTERMATTER

States that there is no detectable gain or States that there is no detectable gain or loss in the quantity of matter, before and loss in the quantity of matter, before and after the reaction.after the reaction.

DALTON’S ATOMIC THEORYDALTON’S ATOMIC THEORY

Dalton’s ideas may be stated as follows:Dalton’s ideas may be stated as follows:• An element is composed of extremely An element is composed of extremely

small individual particles called atoms.small individual particles called atoms.• All atoms of a given element have All atoms of a given element have

identical properties which differ from those identical properties which differ from those of other element.of other element.

• Atoms can not be created, destroyed, or Atoms can not be created, destroyed, or transformed into atoms of an other transformed into atoms of an other element.element.

• Compounds are formed when atoms of Compounds are formed when atoms of different element combine with each other different element combine with each other in simple numerical ratio.in simple numerical ratio.

SOLUTIONSOLUTION

• Solution may be defined as Solution may be defined as homogenous mixture of homogenous mixture of different chemical different chemical substances, which having substances, which having the same chemical the same chemical composition and physical composition and physical properties every where.properties every where.

..

CONCENTRATION OF A CONCENTRATION OF A SOLUTIONSOLUTION

The concentration of solution is defined The concentration of solution is defined as:as:

The amount of solute present in a given The amount of solute present in a given amount of solution. Concentration is amount of solution. Concentration is generally expressed as the quantity of generally expressed as the quantity of solution in a unit volume of solution.solution in a unit volume of solution.

Quantity of soluteQuantity of solute

Concentration: ----------------------------Concentration: ----------------------------

Volume of solution Volume of solution

TYPES OF SOLUTIONSTYPES OF SOLUTIONS

..SR. NO

STATE OF SOLUTE

STATE OF SOLVENT

E X A M P L E

1 GAS GAS AIR

2 GAS LIQUID OXYGEN IN WATER, CO2 + WATER

3 GAS SOLID ADSORPTION CFE2 BY PALLADIUM

4 LIQUID LIQUID ALCOHOL IN WATER

5 LIQUID SOLID MERCURY IN SILVER

6 LIQUID GAS MISY

7 SOLID LIQUID SUGAR, SALT IN WATER

8 SOLID SOLID METAL ALLOYS, CARBON IN STEEL

9 SOLID GAS SMOKE

DILUTE SOLUTIONDILUTE SOLUTIONA solution containing a relatively low A solution containing a relatively low

concentration of solute is called concentration of solute is called dilute solutions.dilute solutions.

WAY OF EXPRESSING CONCENTRATIONWAY OF EXPRESSING CONCENTRATIONA.A. Percent by weightPercent by weightB.B. Mole FractionMole FractionC.C. MolarityMolarityD.D. MolalityMolalityE.E. NormalityNormality

PERCENT BY WEIGHT.PERCENT BY WEIGHT.It is the weight of the solute as a percent of It is the weight of the solute as a percent of the total weight of the solution.the total weight of the solution.

Wt. of soluteWt. of solute% By weight of solute = ---------------- X 100% By weight of solute = ---------------- X 100

Wt. of SolutionWt. of SolutionEXAMPLE:EXAMPLE:If a solution of HCI contains 36% HCI by If a solution of HCI contains 36% HCI by weight, it has 36 GM of HCI for 100 G of weight, it has 36 GM of HCI for 100 G of solution.solution.

EXAMPLE:EXAMPLE:What is the % by weight of NaCl if 1.75 G of What is the % by weight of NaCl if 1.75 G of NaCl is dissolved in 5.85 G of water.NaCl is dissolved in 5.85 G of water.

MOLE FRACTIONMOLE FRACTION(It is denoted by X) of solute is defined as the (It is denoted by X) of solute is defined as the ratio of the number of moles of solute and the ratio of the number of moles of solute and the total number of moles of solute and solvent:total number of moles of solute and solvent: Moles of soluteMoles of soluteX solute = --------------------------------------------X solute = -------------------------------------------- Moles of solute + Moles of solventMoles of solute + Moles of solvent

n Nn NX Solute +--------- X Solvent------------X Solute +--------- X Solvent------------ n + N n + Nn + N n + N

X Solute + X Solvent = 1X Solute + X Solvent = 1

EXAMPLEEXAMPLE

• Calculate the mole fraction of HCI in Calculate the mole fraction of HCI in a solution of Hydrochloric Acid in a solution of Hydrochloric Acid in water, containing 36% HCI by weight.water, containing 36% HCI by weight.

MOLARITYMOLARITY(Symbol M) It is defined as No of moles of (Symbol M) It is defined as No of moles of solute per litre of solution. If n is the number solute per litre of solution. If n is the number of moles of solute and V litres . The volume of of moles of solute and V litres . The volume of solution.solution. Moles of soluteMoles of soluteMolarity= ----------------------Molarity= ---------------------- Volume in LitresVolume in Litres nnMolarity = ---------------------Molarity = --------------------- V (in Litres)V (in Litres)If one mole of solute is dissolved in one litre of If one mole of solute is dissolved in one litre of solution then concentration of solution will be solution then concentration of solution will be one molar or 1 M.one molar or 1 M.

Example-1Example-1What is the molarity of a solution What is the molarity of a solution prepared by dissolving 75.5 G of pure prepared by dissolving 75.5 G of pure KOH in 540 ML of solution.KOH in 540 ML of solution.

Example – 2Example – 2

What weight of Hcl is present in 155 What weight of Hcl is present in 155 ML of a 0.540 M Solution.ML of a 0.540 M Solution.

MOLALITYMOLALITYMolality (Symbol m) : It is defined as the Molality (Symbol m) : It is defined as the number of moles of solute per kilogram of number of moles of solute per kilogram of solvent.solvent. Moles of soluteMoles of solute

Molality (m) =Molality (m) = ----------------------------------------------------Mass of solvent in KgMass of solvent in Kg

A solution obtained by dissolving one mole A solution obtained by dissolving one mole of the solute in 1000 G of solvent is called one of the solute in 1000 G of solvent is called one molal or 1 m solution.molal or 1 m solution.

ExampleExampleWhat is the molality of a solution prepared What is the molality of a solution prepared

by dissolving 5 G of toluene (C7H8) in 225 G of by dissolving 5 G of toluene (C7H8) in 225 G of benzene (C6H6)?benzene (C6H6)?

NORMALITYNORMALITY

Normality (Symbol N) : It is defined as Normality (Symbol N) : It is defined as the number of equivalents of solute per the number of equivalents of solute per litre of solution.litre of solution.

Equivalents of soluteEquivalents of solute

Normality (N)=Normality (N)=----------------------------------------------------------

Litres of solutionLitres of solution