Class 9 Chemistry CBSE

Chemistry Concept Maps Class IX • Matter in Our Surroundings • Is matter around us pure • Atoms and Molecules • Structure of Atom

Class-IX(Chemistry) (e.g. NaCl = 58.5 g)

6.023 × 10 Atoms

6.023 × 1023 Ions

23

(e.g. oxygen gas = 32 g)

GAM Gram formula mass

GMM

In terms of mass

In terms of particles

6.023 × 1023 Molecules

(e.g. oxygen atom = 16 g)

Volume N = NA Molar volume

(No. of atoms in a molecule)

n=

Mass N = GAM/GMM NA

Mass GAM/GMM

Atomicity Chemical formulae

Molecule of element

In terms of volume

Volume Mass = GAM/GMM Molar volume

Some useful formulae

Mole

(Mass of one molecule)

Molecular mass

Molecule

Atomic mass

22.42

(Mass of one atom)

Molecule of compound (Positively charged +

ion e.g. K , Ca

2+

)

Atom exist as

Cation Electopositive radicals

Electronegative radicals

ATOM

Valency of ion

Ion

Polyatomic ion

Anion (Negatively charged –

2–

ion e.g. F , O

)

Ionic compound

Formula unit

Formula mass (Mass of one formula unit)

(Mass of 1 mole molecules)

(Mass of 1 mole atoms)

(Short hand representation)

Symbol

(Present two or more atoms e.g. OH–, SO42– )

Dalton's symbols Rules for writing formulae

Formation

GAM

(Present one atom only e.g. H+, Na+ )

(Charged species)

GMM

N NA

Molar mass (Mass of 1 mole)

(Smallest particle of matter)

Monoatomic ion

n=

Modern symbols

Significance

Rules for writing symbols

• Represents name of element • Represents no. of atoms

Class-IX(Chemistry)

MAP-1

Phosphorus

Iron

Volatility

Non-Metals

Solubility

Boiling point

Metals

Metalloids (Intermediate properties of metals & non-metals)

Solid

Based on principle

Melting point

Sublimation

Radioactive

Liquid

Large proportion

Small proportion

(e.g. Water in sugar solution)

(e.g. Sugar in sugar solution)

Classification

Diffusion

Density

(Intermixing of particles on their own)

Gas

Solvent

Solute

Normal

Separation Element

(Water)

Components

Pure substance (only one kind of particles present)

(Matter that can't be broken into simpler ones.)

True solution

Homogeneous

Mixture

SUBSTANCE

–7

(Particle size < 10 cm)

(More than one kind of particles present e.g. soil, air)

Concentration

Compound

Suspension

Heterogeneous

(Consists of 2 or more elements combined chemically

–5

(Particle size > 10 cm) Percentage method

Lime Water

Organic

Classification

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

Colloidal solution –7

–5

(Liquid or solid in (Particle size between 10 – 10 cm) (Solid in solid e.g. milky glass) gas e.g. fog, smoke) (Obtained from living beings Aerosol e.g. alcohol, sugar) Salt (Gas in liquid Foam e.g. shaving cream) (Formed by acid & base

Acid (Turns blue litmus red e.g. HCl, H2SO4)

Tyndall Effect

Base

e.g. NaCl, CaCO3)

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

(Liquid in liquid e.g. milk)

Classification

Solid sol Gel Solid foam

Emulsion Sol (Solid in liquid e.g. blood)

(Gas in solid e.g. Pumice)

(Liquid in solid e.g. butter)

Mass % of solute m solute M solution

× 100

Volume% of solute v solute × 100 V solution

Class-IX(Chemistry)

MAP-2

Water

Alcohol

Solvent MgO

Al2O3

Adsorbent medium

Principle (Ability to sublime) Example (Sand & I2)

Method

Principle (Density)

Filter paper

Principle (Relative solubility & affinity of constituents)

Principle (Solubility)

Sublimation

Centrifugation

Chromatography

Principle (Density)

Example (Components of ink)

SEPARATION TECHNIQUES

Using Suitable Solvent Example (Sugar/Sand) Principle (Boiling point)

Example (separation of cream from milk)

Separating funnel

Fractional distillation

Evaporation Distillation Example (Coloured components of blue ink solution)

Principle (Boiling point)

Principle (Boiling point)

Example (Oil & Water)

Example (Alcohol & water)

Class-IX(Chemistry)

MAP-3 Liquid N2 boils off followed by liquid O2

Heavy impurities settle down

Suspended impurities separates Rusting

Fractional distillation

Combustion

Sedimentation Filtration Example

SEPARATION OF GASES FROM AIR

CHANGES IN MATTER

CITY WATER SUPPLY

Chemical change

Definition

Purification

Liquefaction

Physical change

Sterilization

(Change in chemical Characteristics properties) • New product formed • Permanent and irreversible change • Energy absorbed or evolved

(At high P & low T) Example

Definition (Change in physical Characteristics properties) Removal of dust, gases & water vapour

Removal of harmful micro organism

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

Condensation

Class-IX(Chemistry)

Freezing

Melting point

Freezing point

Condensation point

Boiling point Condensation

Latent heat Melting

n

Solid to liquid & vice versa

n

Humidity

Surface area Temperature

Wind speed

n

Liquid to gas & vice versa

Boiling (Heat energy required to change 1 kg of liquid into gas at Latent heat atmospheric pressure and its B.P.)

By altering temperature

1 Humidity

n

(Heat energy required to change 1 kg of solid into liquid at atmospheric pressure and its M.P.)

Solid to gas & vice versa

W.S.

Sublimation

(Zig-zag motion)

Brownian motion

Camphor

Nature of substance

By altering pressure

Interconversions

Liquefaction (At high P & low T)

Factors affecting

Dissolving solid in liquid

Movement of pollen grains

Evidence

Evaporation

Physical nature

MATTER

Matter consists of particles

(Anything that has mass, occupies space.) Difference between boiling and evaporation

Evaporation It is a surface phenomenon. It occurs at all temperatures below B.P.

Uses of cotton clothes

Boiling

Characteristics

Classification

Solid

It is a bulk phenomenon.

BEC

It occurs at B.P. only.

The rate of evaporation The rate of boiling does depends upon the surface not depend upon the area of the liquid, humidity surface area, wind speed, temperature & wind speed and humidity.

Plasma

Liquid

Small particle size Interparticle spaces

Cohesive force (between similar atoms)

Interparticle attraction

Particles moving constantly

Gas Diffusion

(between dissimilar atoms) Adhesive force

Class-IX(Chemistry)

( In cancer, thyroid etc.)

Medicine

(Cracks in metal casting)

(to find the age of fossil)

Carbon dating

Reaction (e.g. esterification reaction) mechanism

Industry

(No. of protons) (Sum of protons & neutrons)

Mass number

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

Application

(Traces used Agriculture for plant nutrition)

Fractional atomic mass (Diff. physical properties same chemical properties)

(Diff. Z, same A)

Atomic number

Isotope

Isobar

Characteristics

(Same Z, diff. A)

Octet rule Isotone

Valency

Isoelectronic

(Same no. neutrons in different atoms)

(Combining capacity of an atom)

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

Electron

Proton

Discovery J.J. Thomson

E. Goldstein

James Chadwick

e

p

n

Nature

Negatively charged

Positively charged

Neutral

Relative charge

-1

+1

0

Relative mass Absolute mass

1.602 × 10

-19

C 1.602 × 10

1 1837

9.109 × 10

-19

C

1 -28

g

1.6725 × 10

(Contains protons & neutrons)

Neutron

Symbol

Absolute charge

Electronic configuration (Distribution of electrons in shells)

Electron Property

(8 electrons in outermost shell)

Fundamental particles

Proton

0

Neutron

-24

g 1.6748 × 10

-24

ATOM

Main features (Atom is electrically neutral)

(Electrons revolve)

Bohr's model

g

Rutherford model

Postulates

(K, L, M, N)

Defects (Facts of Rutherford experiment)

• Most a -particles Observation passed straight. • Some deflected through large angles • Some retraced their path

Defects Alpha particle scattering experiment

a -particles

Nucleus

Extranuclear region

(Smallest particle of matter)

Thomson model

1

Atomic structure

Shell

• 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.

Orbital Conclusion •Large empty space • Nucleus inside atom • Very small nucleus as compared to atom

Subshell (s, p, d, f)