Chemistry Concept Maps Class VII • General Chemistry • Sorting Materials In Groups • Physical and Chemical Change • Acids, Bases and Salts • Fibre To Fabric • Air • Separation of Substancs • Water A Precious Resources • Waste Water Story
Magnetic recording tapes , video cassettes curtains
1. Absorbs less water 2. Strong , light,elastic and resists wrinkles
Uses
Light, elastic and high tensile strength
Properties
Properties
Cotswool, polycot, terrywool
Blended
Umbrellas, parachutes, socks Uses
Polyester (terylene or mylar or dacron) Nylon
Wool
FIBRES
Natural
Acrylic (Orlon or Acrilan)
Synthetic
A thread or filament from which a cloth is made
Silk
Uses
Cotton
Semi synthetic Properties
Formation
Air and water proof
Rayon (Artificial silk) Shirt, ties, lining etc.
Uses
Properties 1. Absorbs moisture 2. Lustrous and resembles silk
Uses
Warm, soft and light
Sweaters, socks
Spandex (Lycra)
Koroseal
Viscose process
Properties
Uses Rain coat, bathroom curtains
Properties High elasticity and stretchable
Swimming costumes caps, T-Shirts
Liquid N2 boils off followed by liquid O2
Fractional distillation
Heavy impurities settle down
Sedimentation Filtration
SEPARATION OF GASES FROM AIR
CITY WATER SUPPLY
Suspended impurities separates
Chemical change
CHANGES
Example
Definition
Purification
Liquefaction
Physical change
Sterilization
Example
Definition Characteristics Removal of dust, gases & water vapour
Removal of harmful micro organism
Characteristics
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
Example (separation of cream from milk)
Centrifugation
Chromatography
Principle (Density)
Example (Ink/water)
Separating funnel
SEPARATION TECHNIQUES
Using Suitable Solvent Example (Sugar/Sand)
Example (Oil/Water)
Fractional distillation
Evaporation Distillation Principle (Boiling point)
Example (NaCl/Water)
Principle (Boiling point)
Principle (Boiling point)
Example (Alcohol/water)
NaCl + H2O + Heat
acid > H2O H2O
> acid
Dilute acid
Compounds which when dissolve in water gives H+/H3O+ ions e.g. HCl, H2SO4
Mineral acids
On the basis of Source
Definition
Acids
Solution conduct electricity
On the basis of strength Strong acids
Weak acids
Almost completely ionise (H2SO4 , HCl)
Partially ionise
HCOOH a
c
Olfactory Substances whose odour changes in acidic or basic solutions
Concentrated base
On the basis of concentration
Definition
+
Bases
Acids sour in taste bases bitter in taste
Classification
Soluble in water
Properties
Acids turns blue litmus to red base turns red litmus to blue
On the basis of strength
Strong base
Almost completely ionise (NaOH, KOH) Which indicates the nature of particular solution
i d
Indicator
base > H2O
> base
Dilute base
Classification
Organic acids (e.g. HCOOH, CH3COOH)
Neutralization
Concentrated acid
On the basis of concentration
e.g. (H2SO4, HCl)
HCl + NaOH
Compounds which when dissolve in water gives OH– ions e.g. NaOH, NH4OH H2O
Weak base Methyl orange
Partially ionise NH4OH, Ca(OH)2
Artificial
Phenolphthalein
Natural
• Shearing : The fleece of the sheep along with a thin layer of skin is removed from its body.
(saris, jeckets , gloves, carpets) Uses
Scouring :The sheared skin with hair is thoroughly washed
in tanks to remove grease, dust and dirt Sorting : Separation of hair of different textures is called sorting
(Shiny) Properties
Silk
Wool Plant and animal fibres
Cotton
Jute
FIBRE TO FABRIC
Synthetic or man made
A thread like part in animal and vegetable tissues
Modified natural fibres
Nylon
Semi Synthetic
Rayon (Artificial silk)
1. Absorbs moisture 2. Lustrous and resembles silk
Septic tanks, chemical toilets, combusting pits The excessive growth of algae and aquatic plants due to added nutrients
Sewage disposal
Eutrophication
Humans excreta is treated by earthworms
Vermi-processing toilet
Chemical Oxygen demand (COD)
Sanitation & disease
Poor sanitation and contaminated drinking water is the cause of a large number of dieseases
Index of the waste of water which can be oxidised by strong oxidising agents
WASTE WATER STORY e.g. • Pathogens such as bacteria virus, parastic worms • Soluble organic material such as urea, proteins • Gases such as H2S, CO2, CH4
Consitutent Cleaning of waste water
Biological Oxygen demand (BOD)
Major of the oxygen utilised by microorganisms during oxidation of organic materials
Waster water treatment plant WWTP Treatment of waste water using physical, chemicaland biological process
Solid e.g. ice Liquid e.g. H2O(l)
Gaseous e.g. water vapours
Forms of water Water management proper use of water
e.g. Oceans, rivers, lakes, ice caps
Availability of water
Increasing population
Element hydrogen & oxygen
Water a precious resources
Depletion water table
Composition of water Mass ratio hydrogen : oxygen 1 : 8
Increasing industries
Water cycle Chemical properties Action with litmus Inert
Physical properties
Density 1 gm/cc Action with metals 2K + 2H2O(l)
2KOH(aq) + H2O(g)
Melting point 0ºC
Boiling point 100ºC
Moving air
Sailing yachts
Wind mill Exosphere
Dispersal of seeds
Thermosphere
Birds , bats can fly
Uses
Mesosphere Other gases, carbon dioxide (0.03%) and water vapour
Argon (0.934%)
AIR
Stratosphere
Oxygen (20.946%)
Composition
Atmosphere Troposphere
The transparent, thick and invisible envelope of air surrounding us
Nitrogen (78.084%)
He, Ne, Ar, Kr, Xe
Inert gases
Dust
Components CO2
Water vapour Oxygen
Nitrogen
Change that alters the physical properties of matter without changing the chemical composition Copper sulphate solution Sand Sand bath Wire gauze
Iron vessel
Action of heat on iodine
Switching on an electric bulb
Defintion No new product is formed
Burner
No net gain or loss of energy
Tripod stand
(Pure soluble substance seprates out in the form of crystals)
Crystallisation
Example
Physical changes
Characterstics
Change is temporary and reversible
Dissolving of NaCl in water
No change in the weight of substance
CHANGES IN MATTER
Change in the weight of new substance Change is permanent and irreversible
Defintion
Characterstics New product is formed Net gain or loss of energy
Chemical changes
Change that alters the chemical properties of matter with changing the chemical composition
Air
Burning of Mg in air
Example
Corrosion
Air
Layer of oil
1. Presence of air Rusted nails 2. Presence of water
Dry Air
Non-rusted nails
Non-rusted nails
Anhydrous CaCl2
Conditions (A) (Air and Water)
Burning of LPG
Rusting Preventation
Defination (Iron surface gets covered with a brown flaky substance)
(B) (Boiled distilled water)
Equation 4Fe + xH2O + 3O2
2Fe2O3.xH2O
1. Iron surface coating with thin layer of paint, varnish 2. Iron surface coating with zinc (galvanization) 3. By alloying (Fe, Cr, Ni)
(C) (Only dry air)
