Class 8 Chemistry CBSE

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Synthetic Fibres and Plastics

Concept Maps

Class VIII

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Metals and Non-Metals

•

Coal and Petroleum

•

Combustion and Flame

Chemistry

Spandex

(Lycra)

FIBRES

Semi synthetic

Synthetic

Formation

Koroseal

Polyester (terylene or mylar or dacron) 1. Absorbs less water

2. Strong , light,elastic and resists wrinkles

Sweaters, socks High elasticity and stretchable

Cotswool, polycot,

terrywool

Natural

Blended

Acrylic

(Orlon or Acrilan)

Nylon Air and water proof

Light, elastic and high tensile strength

Rayon

(Artificial silk)

1. Absorbs moisture 2. Lustrous and resembles silk

A thread or filament

from which

a cloth is made

Viscose process

Wool

Silk

Cotton

Properties Uses Rain coat, bathroom curtains Uses Properties Shirt, ties, lining etc. Properties Uses Swimming costumes caps, T-Shirts Uses Warm, soft and light Properties Uses Umbrellas, parachutes, socks Properties Properties Uses Magnetic recording tapes , video cassettes

curtains

PLASTICS

Types

On the basis of arrangement

of monomer unit

On the basis of their

reaction to heat

Thermosplastic Thermosetting plastic Polythene polymer of ethene PVC polymer of vinyl chloride PS polymer of styrene PET (polymer of ethylene glycol & terphthalic acid)

PP (polymer of propylene) Cross-linked Bakelite,Melamine Linear PVC,HDPE Branched LDPE Melamine Bakelite (decorative objects,

dinner set) Monomer

(Melamine & formaldehydae)

(Phenol & formaldehyde)

(combs, switches, table top laminates phonograph recrods)

• Soil and water pollution

• On burning produces

toxic gases

• Death of animals

Reduce, Reuse, Recycle and Recover

Poor conductor of heat and electricity, insoluble in water non-reactive, strong, durable, light

Problems Solutions

Properties Polymeric material which can be easily moulded

or set into any desired shape and size

Monomers

Properties

(Hard, stiff and insulator) Uses

Properties

(Hard and unbreakable)

NON-METAL

Chemical

properties

Electro negative

nature

Physical

properties

Uses

Low densities except I , diamond 2 Low m.p. & b.p except C,B,Si Not sonorous State

Not malleable not lustrous except graphite and iodine A not ductile Brittile excpet (allotrope of carbon i.e. diamond)

Soft and have low tensile has strength except carbon (C,S,I ) etc. solid 2 (Br ) liquid 2 O ,H ,N etc Gas 2 2 2 Reaction with oxide Reaction with oxygen Reaction with base Reaction with salt solution

Does not-metal displaces less reactive non-metal from its salt solution

Acidic CO , SO2 2

Neutral NO, N O, H O2 2

More reactive non-metal displaces less reactive non-metal from its salt solution

2NaBr (aq) + Cl (g)2

P + NaOH + 3H O4 2

2NaCl + Br (g)2

NaH PO + PH2 2 3

reaction water & dilute acid no reaction

Oxides

Oxides

Reaction P + 3NaOH + 3H O4 2 3NaH PO + PH2 2 3

Electronic

configuration

have 4 to 8 valence electrons

Load conductor of heat & electricity except allotrope of carbon

Chemical

properties

METAL

Chemical

properties

Reducing agent

ReactivitySeries

Uses

Electronic

configuration

i d 3 electrons

invalence shell

Hard & posses

high tensile strength

excpet Na,K

Malleable

Ductile

High melting &

boiling point

except CS, Ga, Fr

Sonorous

High density

Lustrous

Good conductor of

heat & electricity

except lead Cl

Displacement

reaction

Reaction with

oxygen

Na

Na + e

+ –

Basic oxide

Na O, CaO

2 2 3 Amphoteric oxide ZnO, Al O

Reaction with

salt solution

Zn(s) + CuSO (aq)

4

ZnSO (aq)

4

Reaction with

dilute acid

Na + 2HCl

2NaCl + H

2

Al + 3H SO

2 4

Al (SO ) + H

2 4 3 2

Reaction with

water

Oxides

Fe(s) + 4H O

2

4H O

2

Hydroxide

Na(s) + H O

2

NaOH + 1/2H

2

MgO + 2H O

2

Mg(OH) + H

2 2

Li

K

Ba

Na

Ca

Mg

Al

Zn

Fe

Sn

Pb

H

Cu

Hg

Ag

Pt

Au

FOSSIL FUEL

Petroleum

Concentration

Type

Non-renewable

Renewable

Exhaustible

Natural resources

Coal

Deposits

Jharkhand mp & wb

Uses

Fuel synthetic petrol and synthetic natural gas organic compounds obtained

Peat

Lignite

Bitmunous

Anthracite

Types

Products obtained

on destructive distillation

Coke

Uses

Properties

Coal tar

Uses

Properties

Chemical substance to repare dyes,explosives, pain perfumes

Thick, black liquid with unpleasant smell

Coal gas

Properties

Uses

Heating, cooking heat source

Gases and high calorific value

Ammonical

liquor

Properties

Uses

Gases and high

calorific value

Natural gas

(55 kJ/g)

Domestic and industrial fuel Manufacture of H required in fertilizers 2

All carbon fource carbon used as filler in manufacture of tyres Deposists Tripura, Rajasthan, Maharastra& Krishna Godavari delt Properties Cleam fuel Leaver no residue no poisonon agases Deposists

Kuwat, sandi Arabia, Iraq china, USA Rusia Likya etc.

Formation

Sand

Resisdual orl Faraffin Lubrating oil Food oil Disel oil Kerosene Petrol Petroleum gas

Nonluminous zone (hottest) Luminous zone (moderately hot) Inner dark zone

Blue

Luminous

COMBUSTION

FLAME

No residue

Excess

of oxygen

Non

Luminous

More light Yellow Unsufficient oxygen Black soot

Less light

CO causes suffocation, etc 2 CO causes global warming SO , NO causes acid rain 2 2 Attainment of ignition temperature

Products and

their effects

Unburnt carbon causes respiratory diseases

Conditions

required

Combustible substance Supporter O2 Complete

Types

Incomplete Slow Rapid Spontaneous

Fuel

Types

Solid _Gases Liquid CNG LPG Hydrogen 2H O + Heat2 No resisdue H + O2 2

Highest calorific value (150 kJ/g) Low ignition temperature and costlier

CH + C H + C H4 2 6 3 8

Colourless, odourless and inflammable gas

Calorific value 50 kJ/g

Calorific value 55 kJ/g No resisdue and clean fuel CH + O4 2 CO + H O + heat2 2

Low ignition temperature and cheaper

Diesel Petrol