Chemisty Book Notes for Class XI

Chemistry

Sindh Text Book Board, Jamshoro.

INTERMEDIATE STAGE CHEMISTRY BOOK ONE

FOR CLASS XI

For

Sindh Textbook Board, Jamshoro.

Book arr a rranged by www.mynoteslibrary.co eslibrary.com m

1

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Chemistry


CONTENTS CHAPTER

1

INTRODUCTION TO THE FUNDAMENTAL CONCEPTS OF CHEMISTRY

3

CHAPTER

2

THREE STATES OF MATTER

7

CHAPTER

3

ATOMIC STRUCTURE

19

CHAPTER

4

CHEMICAL BONDING

25

CHAPTER

5

ENERGETICS OF CHEMICAL REACTION

30

CHAPTER

6

CHEMICAL EQUILIIBRIUM

35

CHAPTER

7

SOLUTION AND ELECTROLYSIS ELECTROLYSIS

40

CHAPTER

8

INTRODUCTION TO CHEMICAL KINETICS

43

SCIENTIFIC REASONS

45















Chemistry


Chapter 1 INTRODUCTION TO THE FUNDAMENTAL CONEPTS OF CHEMISTRY CHEMISTRY: The branch of science that deals with the properties, compositions and structure of matter and the changes occurring in matter and the laws under which these changes occur is called as chemistry. BRANCHES OF CHEMISTRY:        

Organic chemistry Inorganic chemistry Physical chemistry Bio chemistry Analytical chemistry Nuclear chemistry Industrial chemistry Environmental chemistry

BASIC DEFINITIONS: ATOM: The smallest particle of an element is called called as an atom. MOLECULE: When two or more than two atoms are combined together is called as molecule. FORMULA WEIGHT: The total sum of the weights of the atoms present in a substance is called as formula weight MOLECULAR WEIGHT: The sum of the atomic masses present in a substance is called as molecular weight. EMPIRICAL FORMULA: The simplest formula of a c hemical compound that expresses the number of each kind of atom present in the molecule of a compound is called as empirical formula. Example: The empirical formula of water is "H2O". It indicates that the water molecule is















Chemistry

1. 2. 3. 4. 5.


First detect the elements that are present in the compound. Determine the masses of each element present in compound. Then calculate the percentage of each element that is present in compound. After that determine mole composition of each element present in co mpound. in last Determine simplest ratio between the element present in compound.

MOLECULAR FORMULA: The formula that represents number of atoms in each elemet present in the compound is called as molecular formula. MOLECULAR MASS: The sum of the masses present in a molecule is called as molecular mass. GRAM MOLECULAR MASS: The molecular mass if expressed in grams then it is called as gram gr am molecular mass. MOLE: The atomic mass or molecular mass of a substance if expressed in grams is called as mole. FORMULA: Number of moles of = mass of substance (in grams) / molecular mass or atomic mass or formula mass AVOGADRO’S NUMBER: One mole of any s ubstance contains equal number of particles (atoms or molecules or ions).Value of this number is 6.02 x 10 23. ATOMIC MASS: The weight of an atom is called as atomic mass. 1 unified atomic mass unit is defined as 1/12 of the mass of a single carbon-12 atom. SIGNIFICANT FIGURE: Significant figures are reliable digits known with certainty in a given number. The number of significant figure refers to the precision and accuracy of measured quantity, in this numbers the last digit may not be precisely mentioned, the value of last digit is uncertain. RULES OF SIGNIFICANT FIGURE: 1. All non zeros are significant figures. E.g. 789 has 3 significant figures 2. Zero between non significant digits are significant. e.g. 4002 has 4















Chemistry


5. Zeros that locate the decimal point in numbers larger than one are not necessarily significant. e.g. 40 have one significant figure. RULES OF ROUNDING OFF DATA: RULE No 1: If the last digit is greater than 5, then add "1" to the last digit to be hold and drop all digits farther to the right. For example: 4.788 example: 4.788 are rounded off to the 4.78 or 4.8. RULE NO 2: If the last digit is less than 5, then simply write it as it is without adding any number to the last digit. For example: 5.531 example: 5.531 are rounded as 5.53 if we want three significant digits. 5.531 is rounded off as 5.5 if we want two significant figures. RULE NO 3: If the last digit is exactly equal to 5 then: (A) If the digit to be retained is even, then just drop the "5". For example: 3.35 is 3.35 is rounded off to 3.3 for two significant figures. 3.3565 is 3.3565 is rounded off to 3.356 if we need four significant figures. (B) If the digit to be retained is odd, then add "1" to it. For example: 4.15 is 4.15 is rounded off to 4.2 if we need two significant figures. 4.1375 is 4.1375 is rounded off to 4.138 if we need four significant figures. We know that zero is an even number 4.05 is 4.05 is rounded off to 4.0 if we need two significant figures. ADDITION AND SUBTRACTION OF SIGNIFICANT FIGURE: 3.325 + 12.5 12.5 =15.825 (actual answer by using calculator) Answer after rounding off: 15.8 MULTIPLICATION MULTIPLICATION AND DIVISION OF SIGNIFICANT FIGURES: 2.5337 x 3.8 =9.6 2806(actual answer by using calculator) Answer after rounding off: 10 STOICHIOMETRY: The quantitative relationship between the reactants reactants and products in a balanced chemical equation is called as stoichiometry. TYPES OF STOICHIOMETRIC CALCULATIONS: It is divided into following three categories 1. Mass-Mass relationship















Chemistry


LIMITING REACTENT: The reactant that is totally consumed during the chemical reaction due to which the reaction is stopped is called limiting reactant.

















Chemistry


Chapter 2 THREE STATES OF MATER MATTER: Anything that has mass and occupies some space is called as matter. ATOM: Matter is composed of small tiny particles that are called as atoms. Matter has three states Solid Liquid Gas SOLID:    

Solid has a definite shape. It has fixed volume. We cannot compress solid easily. The rate of diffusion is solids are very low.

LIQUID:    

Liquid has no definite shape that means that it can easily change its shape. It has a fixed volume. It can be compressed to the negligible The diffusion of a liquid is possible if and only if the both liquid are polar or non polar.

GASES:   

The gas neither has a fixed volume nor have a fixed shape. The molecules of gas are in continuous motion. The molecules of gas can easily be diffused.

PRESSURE:

















Chemistry

V 


1

P V= (constant)1/P PV=constant SECOND STATEMENT: The product of pressure and volume remains constant at constant temperature. GRAPHICAL REPRESENTATION REPRESENTATION OF BOYLE’S LAW: The Graph between P and V is a smooth curve that shows that they are inversely proportional to each other. This curve is called as “Parabola”.

V

P

The graph between between V V and 1/P is a straight line.

















Chemistry


V

1/P

CHARLE’S LAW: The volume of a gas is inversely proportional proporti onal to the absolute temperature where the pressure remains constant at that time.

V  T V= (constant) T V/T=constant SECOND STATEMENT: The ratio of volume and temperature temperature remains constant at constant pressure. GRAPHICAL REPRESENTATION OF CHARLE’S LAW:

















Chemistry


V

T ABSOLUTE SCALE OF TEMPERATURE OR ABSOLUTE ZERO: This law states that, The volume of the gas increases or decreases to 1/273 times of its original volume for each 0 ºC change of temperature. GRAPHICAL REPRESENETATION:

V

-273c

T

According to this statement the volume of a gas would theoretically be zero at 273ºC. But this temperature has never been achieved for any gas because all the

















Chemistry


Volume of a given mass is inversely proportional to the applied pressure and temperature temperature remains constant.

V 

1 P

------------i

According to the charle’s law The volume of a gas is inversely proportional to the absolute temperature where the pressure remains constant at that time.

V  T -------------ii According to the Avogadro’s law: The volume of a gas is directly proportional to the number of moles. mole s.

V  n ----------iii By combining equation no I, ii, iii we get

V  T .n. V  Tn

1 P

P

V  (const ) Tn

P

const = R

V=RTn/P PV  nRT This is called as ideal gas equation. R= universal gas constant R= 0.0821dm3.atmosphere/ mole.K VALUE OF R: Consider one mole of an ideal gas at S.T.P We know that one mole of gas occupies 22.4dm3 volume. Data: T=0 C



















Chemistry

        


These molecules are widely separated from each other and are so small that they are invisible. The size of the molecules is very small as compared to the distance between them. There is no attractive or repulsive force between molecules so they can move freely. The molecules are very hard and perfectly elastic so when they collide no loss of energy takes place. The gas molecules are in continuous motion they move in a straight path until they collide. During their motion these molecules are collided with one another and with the walls of the container. The collision of the molecules is perfectly elastic. When molecules collide they rebound with perfect elasticity and without loss or gain of energy. The pressure of the gas is the result of collision of molecules on the walls of the container. The average kinetic energy of gas molecules depends upon the upon the absolute temperature. temperature. At any given temperature the molecules of all gases have the same average kinetic energy (1/2 mv2).

TYPES OF SOLIDS: There are following types of solids. Crystalline solids Amorphous Solids DIFFERENCE BETWEEN CRYSTALLINE SOLIDS AND Amorphous solids:



















Chemistry


UNIT: Poise, UNIT: Poise, N.S/m2 FACTORS AFFECTING VISCOSITY: These are the factors that depend on the vis cosity. o

SIZE OF MOLECULES:

The viscosity of liquid depends upon size of the molecule The viscosity is directly proportional to the size of the molecules that large the size of molecules the greater the viscosity. o

SHAPE OF MOLECULES:

Shape of molecules also affects the viscosity. The spherical shape molecule has low resistance and can easily flow. o

INTERMOLECULAR FORCES:

The viscosity is directly proportional to the intermolecular forces. The liquids having large intermolecular forces having greater viscosity. o

TEMPERATURE:

The viscosity is inversely proportional to the temperature so we can say that the viscosity of a liquid decreases as the temperature increases. o

SURFACE TENSION:



















Chemistry

o


INTERMOLECULAR FORCES:

The intermolecular forces are directly proportional to the surface tension. That means that as the intermolecular forces increases surface tension of liquid is called as intermolecular forces. LATENT HEAT OF FUSION: The amount of heat that is required to melt unit mass of a solid is called as latent heat of fusion. UNIT: J/kG FORMULA: Q=m x Hf Where m = mass of solid Q= amount of heat CRYSTAL SYSTEM: There are seven types of crystal s ystem. 1. CUBIC CRYSTAL SYSTEM:



















Chemistry


4. RHOMBOHEDRAL CRYSTAL SYSTEM: When all the edges are same or equal then it is called as rhombohedral crystal system. In this case all the angles are equal but not equal to 90 o. For example: KNO3 AgNO3 5. HEXAGONAL CRYSTAL SYSTEM: In this system two sides are same but third side is different and the angle between equal edges is 90 and the angle between third angle is equal 120. For example: Graphite 6. MONOCLINIC CRYSTAL SYSTEM: All the edges are different in this sy stem. Two angles angl es are equal to 90 but third angle is not equal to 90. For example:



















Chemistry


METALLIC CRYSTALS: When atoms are joined together by metallic bond then it is called as metallic bond. CHARACTERISTICS OF METALLIC CRYSTAL: 

   

Metallic crystals are very hard. They have high melting point and boiling point. They have shiny surface. They conduct electricity and heat. They are ductile and malleable.

IONIC CRYSTAL: Solids that have ionic bond in their structure is called as ionic crystals. ionic crystals. CHARACTERISTICS CHARACTERISTICS OF IONIC BOND:    

They They They They

are hard in nature. he high melting and boiling point. are not ductile. have electricity in molten state.

COVALENT CRYSTAL:





















Chemistry


The total pressure exerted by all the gasses is equal to the sum of collisions of the molecules exerted by individual gas. DERIVATION: Consider a mixture of three different gases a , b and c in a container of volume V at T. Consider that the partial pressures o f these gases are P a ,Pb and Pc respectively and total pressure of mixture is P t. Let there are n a ,nb and nc moles of each gas respectively and the total number of moles are n t. Using general gas of equation PV=nRT For gas a Pa = naRT/V-------i For gas b





















Chemistry

r1 r2


d 2



d 1

MATHEMETICAL REPRESENTATION: For gas a

r  rK

1 d 1

1 d 1

----------i

For gas b

r 

1 d





















Chemistry


Chapter 3 ATOMIC STRUCTURE ATOM: The smallest particle of an element that represents all properties of element is called as atom. FUNDAMENTAL PARTICLE OF ATOM: Atom has following important particle Electron Proton Neutron





















Chemistry


WORKING OF DISCHARGE TUBE: Discharge tube contains a glass fitted inside it fitted with two electrodes placed opposite to each other. They are connected to the high voltage battery This tube is sealed and to reduce the pressure of the tube a vacuum pump im used. WORKING: A low pressure and at very high potential difference electric current is passed through the gas. Different result was obtained during different rate of pressure. First when pressure is reduced to 1cm to hg and very low potential difference a spark of light is produced. At 1 mm Hg, the tube is mostly filled with a glow extending from the positive electrode. At 0.001 m Hg, the glow disappears and the walls of the glass tube begin to glow with a brilliant green light.





















Chemistry


TYPE OF RADIO ACTIVE RAYS:

-Rays -RAYS -RAYS Properties of

-Rays

This particle carries positive charge. Its mass is 4 times of hydrogen h ydrogen atom. It has high ionization power. It has small penetration power. These rays produce fluorescence in different substances. It is approximately equal to the 1/10 th of the velocity of light.























Chemistry


CONTINUOUS SPECTRUM: When white light is passed through prism then it is dispersed into its colors. And the resultant spectrum is called as co ntinuous spectrum.





















Chemistry


SPIN QUANTUM NUMBER: They are used to represent spin of an electron in orbital. DALTON’S ATOMIC THEORY:





















Chemistry

simultaneously. RULES OF ELECTRONIC CONFUGUARATION: AUFBAU PRINCIPLE: According to this principle:






















Chemistry


CHAPTER NO 4 CHEMICAL BONDING





















Chemistry


shell. And Cl has 7 electrton in its o uter most shell it require only one electron to complete its outer most orbit. So H share electron with Cl and they both complete their their outer most orbit. TYPES OF COVALENT BOND:







































































































































































































































































Chemisty Book Notes for Class XI

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