watersolution
DESCRIPTION
Chapter 5 form 2TRANSCRIPT
WATER & SOLUTION
WATER & SOLUTION
Facts: 2/3 of earths surface is covered with water.
SCIENCE FORM 2
1
Physical characteristics of water
PURE WATER IS COLOURLESS, ODOURLESS, TASTELESS LIQUID
STATE OF WATER
Physical characteristics of water
Melting
Boiling
Condensation
Freezing
Sublimation
FREEZING AND BOILING POINT OF WATER
Freezing point: the temperature at which water freeze to form ice.
Physical characteristics of water
Boiling point: temperature when water boils to produce steam.
Heat is absorbed
Heat is released
KINETIC THEORY
The effect of impurities on the physical characteristics of water.
Freezing point and melting point of water are same.
Impurities increase the boiling point of water.
Impurities lower the freezing point of water.
The composition of water
O
H
H
Chemical formula: H2O
ELECTROLYSIS OF WATER
Electrolysis is a process of to break down a compound into simpler substances.
A
H2
O2
Water + dilute sulphuric acid
anode
cathode
EVAPORATION OF WATER
SOLUTION AND SOLUBILITY
SOLUTE
SOLVENT
Substances that dissolves
Substances that dissolve the solute
Concentrated solution
It refers to a solution in which much of the water has been removed.
Dilute solution
to make (a liquid) thinner or weaker by the addition of water or the like.
Saturated solution
solution in which the maximum amount of solvent has been dissolved. Any more solute added will sit as crystals on the bottom of the container.
SUSPENSION
Solution suspensionhomogeneousNon-homogeneousClear/transparentCloudy/translucentContains one or more soluble substancesContains one ore more insoluble subtancesContains substances that cannot be easily separatedContains substances that easily be separatedSOLUBILITY The maximum amount of a solute which can dissolve in a given amount of solvent at a fixed temperature.
THE RATE OF DISSOLVING
Time taken for the dissolving process, from the time the solute is added to the solvent until it has completely dissolved.
FACTORS THAT AFFECT THE SOLUBILITY OF SOLUTE IN WATER
Stirring
Volume of solvent
Temperature
Size of solute
WATER AS A UNIVERSAL SOLVENT
Useful solution
e.g: eye drops, antiseptic lotion
Daily activities
Supplies CO2 to aquatic plants
Dissolve substance
e.g: medicinal drugs, poisons
Supply dissolved oxygen to marine animals
Provide plants with nutrients
Transport dissolved nutrients and waste products to various part of the body of living things
Substances that do not dissolve in water may be soluble in ORGANIC SOLVENTS
ORGANIC SOLVENTSUSESCHLOROFORM Stick plastics letter & numbers on the number plats of vehicleBENZENETo stick piece of rubber on a punctured tyreALCOHOLPrepare shellac Dissolve iodine to make antisepticAMYL ACETATERemove lipstick stainTURPENTINERemove paint from the floorLIME JUICERemove rustACIDS AND ALKALIS
ACIDSTaste: Sour.
Touch: Like water.
Tested with litmus paper: Turn blue litmus red.
pH value: From 0 to less than 7.
Reaction with metals: Form hydrogen and a salt.
Reaction with carbonates: Form a salt, water and carbon dioxide.
Reaction with ammonium compounds: No reaction.
ALKALISTaste: Bitter.
Touch: Soapy.
Tested with litmus paper: Turn red litmus blue.
pH value: From above 7 to 14.
Reaction with metals: No reaction.
Reaction with carbonates: No reaction.
Reaction with ammonium compounds: Give off ammonia gas
NEUTRALA chemical reaction in which an acid and alkali react to produce salt and water
ACID + ALKALI SALT + WATER
e.g: NaOH + HCl NaCl + H2O
NEUTRALISATION
APPLICATIONS OF NEUTRALISATION
Shampoos
Hair conditioner
bicarbonate powder
slaked lime
toothpaste
METHODS OF WATER PURIFICATION
SEDIMENTATION
FILTRATION
CHLORINATION
OZONE
BOILING
DISTILLATION
UV LIGHT
As the water passes through this vessel, microorganisms are exposed to intense ultraviolet light energy which causes damage to genetic molecules (i.e. nucleic acids: DNA or RNA) needed for reproductive functions.
This damage prevents the microorganism from multiplying or replicating in a human or animal host.
Because the microorganism cannot multiply, no infection can occur. Disinfection of water is achieved when UV light causesmicrobial inactivation.
UV LIGHT
Water from the rivers are channel into the reservoir.
In the Aeration Tank bad smells will be aired and removed from the water.
Alum and Lime are added into the water in the coagulation tank. Alum will make particles join together to form larger particles while lime will decrease the acidity of water.
In the mixing tank, alum and lime will be evenly distributed in the water the water.
The water travels into the sedimentation tank so that large particles will sediment to the bottom.
Lighter particles which floats on the water will flow into the filtration tank, suspended particles will be filtered.
Clean water will then be stored at the storage tank. In the storage tank, chlorine and fluorine will be added in the water.
WATER PURIFICATION
WATER POLLUTION