Melting Point

गलन ांक बबद ु

•The temperature, at which solid melt and transform into

the liquid (at the given atmospheric pressure), is known as

“melting point.”

•The melting point of a solid is an indication of the

strength of the force of attraction between its particles.

•The melting point of ice is 273.16 K, i.e. 00 C.

•The melting point of wax is 630C. The melting point of

iron is 153500C

•The process of melting (i.e. change of solid state into

liquid state) is known as fusion.

Boiling or Vaporisation

उब लन य व ष्पीकरण

•The process in which a liquid substance changes

into a gas rapidly on heating, is called boiling.

•The boiling point of alcohol is 780C, the boiling

point of water is 1000C, whereas the boiling point of

mercury is 3570C

•The boiling point of a liquid is a measure of the

force of attraction between its particles. Higher the

boiling point of a liquid, grater will be the force of

attraction between is particles.

Condensation

सांघनन

•The process of changing a gas (or vapour) to

a liquid by cooling, is called condensation.

when steam (or water vapour) changes into

water on cooling, is called condensation

•Condensation is the reverse of boiling (or

vaporisation).

Freezing

हहमीकरण

The process of changing a liquid into a solid by

cooling, is called freezing when water is cooled, it gets

converted into a solid called ‘ice’. This is called

freezing of water. Freezing means solidification.

Solution, Suspension and Colloid

हवलयन, हनलांबन और कोल इड

Introduction/पररचयA pure substance is that that consists of single type of

particle or particles.

एक शुद्ध पद थथ वह ह ैहजसमें एक ही प्रक र के कण होत ेहैं।

•Mixtures of two or more pure components without any

undesirable substance are known as Mixtures, for

example, water, minerals, soil etc.

हबन ककसी अव ांछनीय पद थथ के दो य अहधक शुद्ध घटकों के हमश्रण

को हमश्रण के रूप में ज न ज त ह,ै उद हरण के हलए, प नी, खहनज,

हमट्टी आकद।

•A homogeneous mixture of two or more substances is

known as solution. For example, lemonade, soda water etc.

दो य अहधक पद थों के एक सम ांगी हमश्रण को हवलयन के रूप में ज न

ज त ह।ै उद हरण के हलए- नींब ूप नी, सोड प नी आकद।

•Solution could be in any form such as – it could be in

liquid, solid, or gaseous.

हवलयन ककसी भी रूप में हो सकत ह ैजसै े- यह तरल, ठोस य गसैीय

में हो सकत ह।ै

•Alloys are another example of mixture that contains

homogeneous mixtures of metals; they cannot be separated

into their components by physical methods. E.g. For

example, brass is a mixture of zinc (approximately 30%)

and copper (about 70%).

हमश्र ध तु हमश्रण क एक और उद हरण ह ैहजसमें ध तुओं क सम ांगी

हमश्रण होत ह;ै उन्हें भौहतक तरीकों स ेअपने घटकों में अलग नहीं

ककय ज सकत ह।ै जसै ेउद हरण के हलए, पीतल जस्त (लगभग

30%) और त ांब (लगभग 70%) क हमश्रण ह।ै

Significant Features of Solution

हवलयन की महत्वपूणथ हवशेषत एां

•Solution is normally a homogeneous mixture. हवलयन एक

सम ांगी हमश्रण ह।ै

•The particles of a solution are even smaller than 1 nm (10-

9 meter) in diameter and hence, these are not visible from

the naked eyes.

एक घोल के कण व्य स में 1 nm (10-9 मीटर) स ेभी छोटे होत ेहैं और

इसहलए, य ेनग्न आांखों स ेकदख ई नहीं दतेे हैं।

•The path of light is not visible in a solution.

हवलयन में प्रक श क म गथ कदख ई नहीं दते ।

The dissolved particles cannot be separated

from the mixture by the simple process of

filtration.

The dissolved particles do not settle down

when it left undisturbed.

हनस्पांदन की सरल प्रकिय द्व र भांग कणों को हमश्रण से

अलग नहीं ककय ज सकत ह।ैहवघरटत होन ेपर

हवघरटत कण नीचे नहीं बैठत ेहैं।

•At a given temperature, when no more solute can be

dissolved in a solution, it is known as „saturated solution.‟

ककसी कदए गए त पम न पर, जब ककसी घोल में अहधक घोल नहीं ड ल

ज सकत , तो इस े'सांतृप्त घोल' के रूप में ज न ज त ह।ै

•At a given temperature, the amount of the dissolved

particles present in the saturated solution, is known as

solubility.‟

ककसी कदए गए त पम न पर, सांतृप्त घोल में मौजूद हवघरटत कणों की

म त्र को हवलेयत के रूप में ज न ज त ह।ै

Types of solution / हवलयनSolution of Solid in a Solid

एक ठोस में ठोस क हवलयन

Metal alloys are the solutions of solids in solids. brass is a solution of zinc

in copper

ध त ुहमश्र ठोस पद थों में ठोस के हवलयन होत ेहैं। पीतल, त ांब ेमें जस्त क एक हवलयन

है

Solution of Solid in a Liquid

एक तरल में ठोस क हवलयन

Sugar solution and salt solution are the solutions of solids in liquids.

चीनी क घोल और नमक क घोल तरल पद थथ में ठोस पद थथ क घोल ह।ै

Solution of Liquid in a Liquid

तरल में तरल क हवलयन

Vinegar is a solution of acetic acid (ethanoic acid) in water.

हसरक प नी में एहसरटक एहसड (एथनेोइक एहसड) क एक हवलयन ह।ै

Solution of Gas in a Liquid

एक तरल में गसै क हवलयन

Soda-water is a solution of carbon dioxide gas in water.

सोड -प नी प नी में क बथन ड इऑक्स इड गसै क एक हवलयन ह।ै

Solution of Gas in a Gas

गसै में गसै क हवलयन

Air is a solution of gases like oxygen, argon, carbon dioxide and water

vapour, etc., in nitrogen gas.

न इट्रोजन गसै में व य ुऑक्सीजन, आगथन, क बथन ड इऑक्स इड और जल व ष्प आकद

गसैों क एक हवलयन ह।ै

Suspension/हनलांबनA suspension is a heterogeneous mixture in which

the solute particles do not dissolve, but rather

remain suspended throughout the bulk of the

medium, is known as „suspension.‟

एक हनलांबन एक हवषम हमश्रण ह ैहजसमें हवलेय कण हवघरटत

नहीं होते हैं, बहकक परेू मध्यम में हनलांहबत रहत ेहैं, इस े

'हनलांबन' के रूप में ज न ज त ह।ै

Significant features of Suspension

हनलांबन की महत्वपणूथ हवशेषत एां

•Particles of a suspension are clearly visible from the

naked eye.

एक हनलांबन के कण नग्न आांखों स ेस्पष्ट रूप स ेकदख ई दतेे हैं।

•The particles of a suspension scatter a beam of light that

passes through it and likewise, its path is visible.

हनलांबन म ेप्रक श ककरण गजु रने पर प्रक श ककरण हबखरती ह ै|

•The salute particles can be separated from the mixture by

the simple process of filtration.

नमकीन कणों को हनस्पांदन की सरल प्रकिय द्व र हमश्रण स ेअलग

ककय ज सकत ह।ै

Colloid/कोल यड़•A heterogeneous mixture is known as

„colloid.‟ E.g. mist, fog, smoke, face cream,

etc.

हवषम ांगी हमश्रण को 'कोल इड' के रूप में ज न ज त

ह।ै ' धुांध, कोहर , धुआँ, फेस िीम इत्य कद।

•The size of colloid particles is too small to see from

the naked eye.

कोल इड कणों क आक र नग्न आांखों स ेदखेन ेके हलए बहुत

छोट ह।ै

•Colloid particles are big enough to scatter a beam

of light passing through it and make the path

visible.

कोल इड के कण बड़े होते हैं जो प्रक श के एक बीम को

हबखरेत ेहैं और इसके म गथ को कदख ई दतेे हैं।

•Colloid particles cannot be separated from the

mixture by the simple process of filtration.

कोल इड कणों को हनस्पांदन की सरल प्रकिय द्व र हमश्रण स े

अलग नहीं ककय ज सकत ह।ै

•The special filtration technique i.e. centrifugation,

can be used to separate the colloidal particles.

हवशषे हनस्पांदन तकनीक य नी सेंट्रीफ्यूगशेन, कोल इडल कणों

को अलग करन ेके हलए इस्तेम ल ककय ज सकत ह।ै

Chromatography/िोमैटोग्र फी The process of separation of components of a

mixture is called as chromatography;

normally it is used for the color separation.

हमश्रण के घटकों के पृथक्करण की प्रकिय को

िोमटैोग्र फी कह ज त ह;ै आमतौर पर इसक उपयोग

रांग पृथक्करण के हलए ककय ज त ह।ै

•Chromatography technique is used for

separation of those solutes that dissolve in

the same solvent.

िोमैटोग्र फी तकनीक क उपयोग उन हवलेय के

पृथक्करण के हलए ककय ज त ह ैजो एक ही

हवल यक में घुलते हैं।

Distillation/ आसवन•The process of purifying a liquid by heating

and cooling means is known as distillation.

हीटटग और कूबलग स धनों द्व र एक तरल को शुद्ध

करन ेकी प्रकिय को आसवन के रूप में ज न ज त ह।ै

Crystallization/ किस्टलीकरणThe process that separates a pure solid in the

form of its crystals from a solution is known

as „crystallization.‟

एक हवलयन से इसके किस्टल के रूप में एक शुद्ध ठोस

को अलग करने व ली प्रकिय को 'किस्टलीकरण' के रूप

में ज न ज त ह।ै '

Tyndall effectThe Tyndall effect, also known as Willis–Tyndall

scattering, is light scattering by particles in a colloid or in a

very fine suspension. It is named after the 19th-century

physicist John Tyndall.

ट इन्डल प्रभ व, हजस ेहवहलस-ट यांडॉल हबखरने के रूप में भी ज न

ज त ह,ै कोल इड में कणों द्व र य हनलांबन में प्रक श प्रकीणथन ह।ै

इसक न म 19 वीं सदी के भौहतक हवज्ञ नी जॉन टटडले के न म पर

रख गय है

•Shining a flashlight beam into a glass of milk is an

excellent demonstration of the Tyndall effect. You

might want to use skim milk or else dilute the milk

with a bit of water so you can see the effect of the

colloid particles on the light beam.

एक ग्ल स दधू में टॉचथ बीम चमक न टटडल प्रभ व क एक

उत्कृष्ट प्रदशथन ह।ै हस्कम हमकक क उपयोग करें य कफर दधू को

थोडे से प नी के स थ पतल करें त कक आप कोलोइड कणों के

प्रक श ककरण पर प्रभ व दखे सकें ।

•An example of how the Tyndall effect scatters blue light

may be seen in the blue color of smoke from motorcycles

or two-stroke engines.

ट यरांड इफेक्ट स्कैटर ब्ल ूल इट को मोटरस इककल य टू-स्ट्रोक इांजन स े

धुएां के नील ेरांग में दखे ज सकत ह|ै

•The visible beam of headlights in fog is caused by the

Tyndall effect. The water droplets scatter the light, making

the headlight beams visible.

कोहरे में हडेल इट्स की कदख ई ककरण टटडॉल प्रभ व के क रण होती ह।ै

प नी की बूांदें प्रक श को हबखरेती हैं, हजसस ेहडेल इट बीम कदख ई दतेी

ह।ै

•The Tyndall effect is used in commercial and lab settings

to determine particle size of aerosols.

एरोसोल के कण आक र को हनध थररत करने के हलए ट इन्डल प्रभ व क

उपयोग व हणहययक और प्रयोगश ल सेटटग्स में ककय ज त है

•Opalescent glass displays the Tyndall effect. The glass

appears blue, yet light that shines through it appears

orange.

ओपलेसेंट ग्ल स ट इन्डल प्रभ व को प्रदर्शशत करत ह।ै क ांच नील

कदख ई दते ह,ै कफर भी प्रक श जो इसके म ध्यम स ेचमकत ह ैवह

न रांगी कदख ई दते ह।ै

• Blue eye color is from Tyndall scattering through

the translucent layer over the eye's iris.

ब्लू आई कलर ट इन्डल स ेहोत ह,ै जो आांख की पररत ररक

पर प रभ सी परत के म ध्यम स ेहबखरत ह।ै

Types of Glass

We know that glass is used for making many articles,

but we cannot use same type of glass for making

everything. This means that we need different types of

glass for different purposes. These types of glass can be

made by changing the chemical composition of

ordinary glass.

Now we will study different types of glass, their

chemical composition and there uses.

1. Soda Glass or Soft Glass or Ordinary Glass

Soda glass is the cheapest and most commonly

used glass. It is made by fusing a mixture of

sodium carbonate, calcium carbonate and silica.

It is called soda glass because it is prepared from

soda ash or sodium carbonate. It is called soft

glass because it becomes soft after heating.

soda glass is prepared from soda ash or sodium

carbonate

Uses:- Soda glass is used for making glass tumblers,

mirrors, window panes, electric bulbs, bottles, and

dishes etc.

2. Potash Glass or Hard Glass

It is prepared by fusing a mixture of

potassium carbonate, calcium carbonate

and silica. As its name indicates it is

very hard and have high melting point.

It is also more resistant to action of

acids.

Uses:- Hard glass is used for making hard

glass laboratory apparatus.

3. Optical Glass

It is prepared by fusing

potassium carbonate, lead oxide

and silica.

Uses:- It is used for making lenses which are used in

spectacles, cameras, microscopes, telescopes and other optical

instruments. It is also used for making glass prisms.

4. Pyrex Glass or Borosilicate

Glass

It is made by fusing a mixture of

sodium carbonate, potassium

carbonate, calcium carbonate, silica,

borax and aluminium oxide.

Uses:- It is used for making laboratory apparatus such as flasks, and

beakers because it can withstand high temperature while heating

without breaking. It is also used for making ampoules which are used

for storing the medicines for injections. In our homes the utensils

which are used in microwave ovens are made up of Pyrex glass.

5. Safety Glass

It is prepared by sandwiching a thin sheet of

plastic between two layers of glass by applying suitable

adhesive on both the sides. These three layers are then

joined together by the action of pressure and heat to

form a single sheet of safety glass. This glass is very

strong. It cannot be broken into small pieces by hitting

with heavy objects. That is why it is called safety glass.

Uses:- It is used mainly for making the

windscreens of automobiles, trains and

aeroplanes. It is also used for making bullet-proof

jackets.

6. Photo Chromatic Glass

This glass has a unique property of becoming

dark coloured when exposed to bright

sunlight and coming back to original state

when bright sunlight is removed. This

happens due to the presence of a layer of

silver bromide over it.

Uses:- This glass is used for making spectacles,

cameras and goggles.

7. Lead Crystal Glass

It is made by fusing a mixture of

potassium carbonate, lead oxide and

silica.

Uses:- This glass has the property of shining

so it is used for making expensive glass

products.

Colours in fireworks

and glass

DLB 54

Colours in fireworks

Red strontium salts,

lithium salts

lithium carbonate,

Li2CO3 = red

strontium carbonate,

SrCO3 = bright red

DLB 56

Orange calcium salts calcium

chloride, CaCl2calcium sulfate,

CaSO4·xH2O,

where x = 0,2,3,5

DLB 58

Gold incandescence of iron

(with carbon),

charcoal, or

lampblack

DLB 60

Yellow sodium compounds

sodium

nitrate,

NaNO3 cryolite,

Na3AlF6

DLB 62

Electric White white-hot metal,

such

as magnesium

or aluminum

barium oxide,

BaO

DLB 64

Green barium compounds +

chlorine

producer

barium chloride,

BaCl+ =

bright green

DLB 66

Blue copper compounds +

chlorine

producer

copper acetoarsenite

(Paris Green),

Cu3As2O3Cu(C2H3O2)2= blue copper (I)

chloride, CuCl =

DLB 68

Purple mixture of strontium

(red) and

copper (blue)

compounds

DLB 70

Silver burning

aluminum,

titanium, or

magnesium

powder or

flakes

DLB 73

Colours in glass

DLB 74

Selenium,copper Oxide(cu2o) -Red

DLB 75

Chromic Oxide -Green

DLB 76

Copper mono oxide - Blue

DLB 77

Iron Oxide - Browns

DLB 78

Manganese oxide-voilet colour

ATOM AND MOLECULE

Introduction:

•It is a smallest particle which may or may not exist freely.

• It is a smallest unit of an element which takes part in a

chemical reaction.

Characteristics:

•Atoms are building blocks of matter.

•They are very small in size around 100 picometer. (10–12 m)

•Atomic radius is measured in nanometer (1 nm = 10–9 m).

•Atoms of most of the elements do not exist freely.

Symbols of Element •It is symbolic representation of name of element.

•Dalton was the first scientist to use the symbols of elements.

•He used symbols which meant a definite quantity of that

element, that is one atom of an element.

•Berzelius suggested that the symbols of elements can be

made by first one or two letters of the name of elements.

• In the beginning, the names of elements were derived from the names

of places from where they had been found first time

e.g. The name of copper was taken from Cyprus.

•Some names were taken from specific colours,

e.g. Gold was taken from English word meaning yellow.

• IUPAC approved the name of elements in those days.

• The symbols of 12 elements are first letters of their names and in many

elements it is first two letters.

•First letter is written in capital and second in small case,

e.g. ‘Al' for Aluminium, Co for Cobalt.

•Some names of elements have been derived from Latin,

Greek or German.

• Latin name of iron is Ferrum (Fe),

• Sodium is Na from Natrium,

•Potassium is K from Kalium.

•They represent one atom of an element, e.g. as shown in the

table.

Atomic Mass •The mass of an atom is called atomic mass.

•Relative atomic mass: It is defined as number of times the given atom of

an element is heavier than 1/12th of the mass of atom of carbon-12.

•Relative atomic mass of an element is also defined as average mass of

an atom as compared to 1/12th of the mass of one atom carbon-12,

e.g. H= 1u, C = 12u, N = 14u, O = 16u, Na = 23u, Mg = 24u, Al = 27u =

S = 32u

Cl = 35.5u Ca = 40u, K = 39u, P = 31u Cu = 6.3.5u, Zn = 65u, Fe = 56u

• Unified mass (atomic mass unit): It is equal to mass of 1/12th of the

mass of 1 atom of C-12.

Molecule of Elements

•It is mostly a group of two or more atoms which are chemically bønded

together, i.e. strongly held together by force of attraction.

•It is a smallest particle of an element which is capable of free existence.

Atoms of same or different elements join together to form a molecule.

Monoatomic: These elements exist as single

atoms.

e.g.

He, Ne, Al, Kr,

Xe, Rn, Na, K,

sFe, Al, Cu, C.

Diatomic: These elements exist as two atoms

bonded together,

e.g.

O2, N2,

Br2, C12,

H2, I2.

•Triatomic: These molecules contain three atoms

e.g. Ozone (O3)

•Tetratomic: Molecules made up of four atoms,

e.g. P4•Octatomic: Molecules made up of eight atoms,

e.g. S8

Molecules of Compounds •Atoms of the different elements combine together in a

definite proportion to form molecules of the compounds, e.g.

H2O (water), NH3 (ammonia), CO2 (Carbon dioxide), CH.

(Methane), CO (Carbon monoxide).

•Each molecule has atoms in a fixed ratio by mass, e.g. in H2O

is 2:16 i.e., 1:8. In NH, the ratio is 14 : 3 by mass.

Ions •The charged species are known as ions.

•Positively charged ion is called a cation, e.g. K+, Na+, Ca2+,

Mg2+, Al3+, Fe2+.

•Negatively charged ion is called an anions, e.g. Cl-, Br-, O2-

,S2-,N3- .

•A group of atoms carrying a charge is called polyatomic ion.

Those compounds which are formed from ions of opposite

charge in a fixed proportion are called ionic compounds, e.g.

CaO has Ca2+ and 02- in the ratio of 5:2, MgO has Mg2+ and

O2- in ratio of 3 : 2, NaCl has Na+ and Cl- in ratio of 23 : 35.5.

Molecular Mass• It is the sum of atomic masses of all the atoms in a molecule

of that substance,

• e.g. molecular mass of H20 = 2*H +1*O = 2 1+1 x 16 = 18 u.

•Formula Unit Mass- It is sum of atomic mass of ions and

atoms present in a formula for an ionic compound,

•e.g. NaCl has 23 + 35.5 = 58.5 u as formula unit mass.

Rules for Writing Chemical Formula

•We first write symbol of elements which are present

in a compound.

•Below the symbol of each element, we write valency.

•Now we cross over the valencies of combining atoms.

•With first atom, we write the valency of second atom

(as a subscript)

With second atom, we write, the valency of the first

atom (as a subscript).

•The valencies or charge on atom must be

balanced (equal).

•When metal and non-metals are present in a

compound, symbols of metals are written first

and then non-metals on the right side.

THANK YOU