Class 9 Chemistry CBSE

(1)

• Matter in Our Surroundings

Concept Maps

Class IX

• Is matter around us pure

• Atoms and Molecules

• Structure of Atom

Chemistry

(2)

Volume Molar volume N NA

=

ATOM

Significance

Atomic

mass

Symbol

Dalton's symbols Modern symbols Rules for writing symbols

Mole

Some useful

formulae Mass GAM/GMM= Volume Molar volume n = Mass GAM/GMM Mass GAM/GMM

=

N NA NA N n = In terms of mass GAM GMM Gram formula mass In terms of particles 6.023 × 10 Ions 23 6.023 × 10 Atoms 23 6.023 × 10 Molecules 23 Molar mass GAM GMM

Atom

exist as

In terms of volume 22.42

Ion

Ionic

compound

Rules for writing formulae Formation Formula unit Formula mass

Monoatomic

ion

Polyatomic

ion

Valency

of ion

Electronegative radicals Electopositive radicals

Anion

Cation

Molecule

Chemical

formulae

Atomicity

Molecule of

element

Molecule of

compound

Molecular

mass

(No. of atoms in a molecule) (Mass of one molecule) (Positively charged ion e.g. K , Ca+ 2+

)

(Negatively charged ion e.g. F , O– 2–

)

(Mass of one formula unit)

(Present two or more atoms e.g. OH , SO– 2–)

4 (Present one atom

only e.g. H , Na )+ + (Charged species) (Smallest particle of matter) (e.g. NaCl = 58.5 g) (e.g. oxygen

atom = 16 g) _{(e.g. oxygen} gas = 32 g)

(Mass of one

atom) _{(Mass of 1} mole molecules)

(Mass of 1 mole)

(Mass of 1 mole atoms)

(Short hand representation) • Represents name of element • Represents no. of atoms

Class-IX(Chemistry)

(3)

Volume%

of solute

Heterogeneous

SUBSTANCE

Mixture

Separation

Based on

principle

Solubility Sublimation Diffusion Volatility Boiling point Melting point Density

Homogeneous

Components

Solute Solvent

True

solution

Suspension

Colloidal solution

Concentration

Percentage method

Classification

Tyndall Effect

Aerosol

Solid sol

Gel

Foam

Sol

Emulsion

Solid foam

Mass % of solute

Pure

substance

Compound

Element

Inorganic

Organic

Acid

Salt

Classification

Radioactive

Normal

Non-Metals

Metalloids

Metals

Solid

Gas

Liquid

Base

Classification

MAP-1

(Matter that can't be broken

into simpler ones.)

(only one kind of

particles present)

(More than one kind of

particles present e.g. soil, air)

(Consists of 2 or more

elements combined chemically

(Obtained from living beings e.g. alcohol, sugar) (Turns blue litmus red

e.g. HCl, H SO )2 4

(Turns red litmus blue e.g. NaOH, KOH)

(Formed by acid & base e.g. NaCl, CaCO )3

(Particle size < 10 cm)–7

(Particle size between 10 – 10 cm)–7 –5

(Particle size > 10 cm)–5

Small proportion Large proportion

msolute Msolution × 100 vsolute Vsolution × 100

(Obtained from rocks and minerals e.g. salt, marble)

(Intermediate properties of metals & non-metals)

Phosphorus

Iron

(Intermixing of particles on their own) Lime Water (e.g. Sugar in sugar solution) (Water)

(e.g. Water in sugar solution)

(Liquid or solid in gas e.g. fog, smoke)

(Gas in liquid e.g. shaving cream)

(Liquid in liquid e.g. milk)

(Solid in liquid e.g. blood) (Gas in solid e.g. Pumice) (Liquid in solid e.g. butter) (Solid in solid e.g. milky glass)

(4)

SEPARATION

TECHNIQUES

Distillation

Principle

(Boiling point)

Fractional

distillation

Example (Alcohol & water)

Separating

funnel

Principle

(Density)

Example (Oil & Water)

Centrifugation

Principle

(Density)

Example

(separation of

cream from milk)

Sublimation

Principle

(Ability to sublime)

Example

(Sand & I )

2

Using Suitable

Solvent

Principle

(Solubility)

Example

(Sugar/Sand)

Evaporation

Principle

(Boiling point)

Example (Coloured components of blue ink solution)

Chromatography

Method

Principle (Relative

solubility & affinity of

constituents)

Example (Components of ink)

Solvent

Water Alcohol

Adsorbent

medium

MgO Al O2 3 Filter paper

Principle

(Boiling point)

MAP-2

(5)

SEPARATION OF

GASES FROM AIR

Removal of dust,

gases & water vapour

CITY WATER

SUPPLY

Liquefaction

Purification

Fractional

distillation

Liquid N boils off

followed by liquid O

2 2

Sterilization

Removal of harmful

micro organism

Sedimentation

Heavy impurities

settle down

Physical

change

Definition

Example

Characteristics

Filtration

CHANGES

IN MATTER

Chemical

change

Suspended impurities

separates

Definition

Example

Characteristics

(At high P & low T)

(Change in physical

properties)

(Change in chemical

properties)

• No new product formed

• Temporary and reversible change • No net gain or loss of energy

• New product formed

• Permanent and irreversible change • Energy absorbed or evolved

Combustion

Rusting

Condensation

MAP-3

(6)

MATTER

Interconversions

Classification

Physical

nature

BEC

Solid

Liquid

Gas

Plasma

Characteristics

Small particle

size

Interparticle

spaces

Particles moving

constantly

Interparticle

attraction

Matter consists

of particles

Dissolving solid

in liquid

Movement of

pollen grains

Diffusion

Brownian

motion

Evaporation

Factors affecting

Temperature

Surface

area

Humidity

Wind

speed

Nature of

substance

Difference

between boiling

and evaporation

Uses of cotton

clothes

By altering

temperature

Solid to liquid

& vice versa

Latent heat

Freezing point Melting point

Freezing

Melting

Liquid to gas

& vice versa

Condensation point Boiling point Condensation Boiling

Latent heat

Solid to gas

& vice versa

Sublimation

By altering

pressure

Liquefaction

Cohesive force Adhesive force

(Anything that has mass, occupies space.)

n n n 1 Humidity n W.S. Evaporation Boiling It is a surface

phenomenon. It is a bulk phenomenon. It occurs at all

temperatures below B.P. It occurs at B.P. only. The rate of evaporation

depends upon the surface area of the liquid, humidity temperature & wind speed

The rate of boiling does not depend upon the surface area, wind speed,

and humidity.

(Zig-zag motion)

(At high P & low T)

(between dissimilar atoms) (between similar atoms)

Evidence

Camphor

(Heat energy required to change 1 kg of solid into liquid at

atmospheric pressure and its M.P.)

(Heat energy required to change 1 kg of liquid into gas at

atmospheric pressure and its B.P.)

(7)

ATOM

Nucleus

Atomic

structure

Extranuclear

region

Bohr's

model

Postulates

Ruther-ford model

Defects

Alpha particle scattering experiment Observation Conclusion

Thomson

model

Defects

Main

features

Fundamental

particles

Neutron

Proton

Electron

Valency

Mass

number

Atomic

number

Electronic

configuration

Isoelectronic

Isobar

Characteristics

Fractional

atomic mass

Application

Agriculture

Industry

Medicine

Carbon

_dating

Reaction mechanism

Shell

Orbital

Subshell

Isotone

Isotope

Octet rule

(Traces used for plant nutrition)

(Cracks in metal casting)

( In cancer, thyroid etc.)

(to find the age of fossil)

(e.g. esterification reaction)

(e.g. Cl = 35.5u, Cu = 63.5 u)

(Diff. physical properties same chemical properties)

(8 electrons in outermost shell) (Same Z, diff. A)

(Diff. atoms, ions molecules with same no. of electrons)

(Distribution of

electrons in shells) (Contains protons & neutrons)

(Electrons revolve)

• Electrons revolve in shells • Fixed energy of each orbit • Energy increases from K to N • No gain or loss of energy in shell • Electron jumps to higher or lower orbit by gain or loss of energy. (K, L, M, N)

•Large empty space • Nucleus inside atom • Very small nucleus as compared to atom • Most -particles

passed straight. • Some deflected through

large angles

• Some retraced their path a (Facts of Rutherford experiment) (Smallest particle of matter) (Diff. Z, same A) (No. of protons) (Sum of protons & neutrons) (Combining capacity of an atom)

(Same no. neutrons in different atoms)

(s, p, d, f)

Property Electron Proton Neutron Discovery J.J. Thomson E. Goldstein James Chadwick

Symbol e p n Nature Negatively charged Positively charged Neutral Relative charge -1 +1 0 Absolute charge 1.602× 10 -19_C _1.602 × 10-19C 0 Relative mass 1 1 Absolute mass 9.109× 10-28g 1.6725× 10-24g 1.6748× 10-24g 1837 1 a -particles (Atom is electrically neutral)