2. Water
• Water are the most essential need for humans.
• Without water life on earth is not possible.
• A single human being should drink at least 5 to 6 liters of water per day.
• 71% of earth’s surface is covered with water.
• Water is used in all the sectors all over the world.
3. Sources of water
There are many sources of water :-
1. Main Source is Rain Water.
2. Other sources are Oceans, Lakes, Ponds, Ground Water.
Rain water are the purest form of water.
4. Uses of water
• Water is used widely in three essential sectors
Water
Agricultural Industrial Domestic
5. Causes of impurities
• As we know rain water are the pure water when they come to contact with
the earth they become impure due to impurities the impurities are:-
1. Dissolved impurities
2. Suspended impurities
3. Colloidal impurities
4. Micro-organisms
6. Types of hardness of water
• There are two types of water Soft water and Hard water.
• There are two types of Hard water they are Temporary Hardness and
Permanent Hardness.
• IDENTIFICATION TEST FOR WATER IS :-
C17H35COONa,C17H35COOK are true soap solutions
H2O+Soap Lather (or) Foam
H2O+Soap No Lather (or) Foam
7. Temporary Hardness
• Temporary hardness of water is caused by
1. Calcium Carbonate(CaHCO3)
2. Calcium Bicarbonate(Ca(HCO3)2)
3. Magnesium Carbonate(MgHCO3)
4. Magnesium Bicarbonate(Mg(HCO3)2)
Temporary hardness can be removed by Simple Boiling process
8. Permanent Hardness
• Permanent hardness of water is caused by
1. Calcium chloride(CaCl2)
2. Calcium sulphate(CaSo4)
3. Magnesium chloride(MgCl2)
4. Magnesium sulphate(MgSO4)
9. Units of hardness of water
• Units of water are
1. PPM (Parts Per Million)
2. MgLit (Milligrams Per Liter)
3. ˚Cl (Degrees of Clark)
4. ˚Fr(Degrees of French)
10. Estimation of hardness of water by EDTA
method
• Steps involved in estimation of hardness of water by Ethylene Di-Amine Tetra
Acetic Acid (EDTA)method are.
1. Preparation of MgSO4.
2. Standardization of EDTA.
3. Estimation of total hardness of water.
4. Estimation of permanent hardness.
5. Calculation of temporary hardness.
Total hardness= Permanent hardness + Temporary hardness
11. Relation between units of hardness of
water
• 1 PPM= 1 part of CaCO3 equivalent hardness causing salt substances
present in 10^6 parts of water.
• 1mglit=1mg of CaCO3 equivalent per 10^6 mg of water.
• 1˚Cl=1 part of CaCO3 equivalent hardness in 70,000 parts of water.
• 1˚Fr=1 part of CaCO3 equivalent per 10^5 parts of water.
1PPM=1MgLit=0.07˚Cl=0.1˚Fr
12. Potable water
• Potable water are the water which are useful for drinking purpose.
• SPECIFICATION OF POTABLE WATER
1. Water should be colourless, clear, odourless.
2. The pH of water should be maintained in between 7.0 to 8.5.
3. The total hardness limit is between 200-600.
So, water are treated in treatment plants to meet all the conditions
that satisfies potable water specifications.
13. Steps involved in a Typical water treatment
plant
1. Water intake.
2. Screening.
3. Aeration.
4. Sedimentation.
5. Filtration.
6. Disinfection.
7. Storage/Water Distribution.
14. Steps involved in a Typical water treatment
plant
1. Water intake- Collecting of water from the sources.
2. Screening- Water are passed through large screens where as large floating particles
are removed.
3. Aeration- Passing of Oxygen gas into water so that the other harmful gasses are
removed like CO2 etc.
4. Sedimentation- Sedimentation beds are provided so that impure particles will be
settled down when left undisturbed.
5. Filtration- Water are passed through filters where small impure particles are
collected away by the filter.
15. Disinfection
• Removal of harmful micro-organisms present in the water is known as
disinfection.
• There are many types of disinfection techniques. They are:-
1. Chloramines.
2. Bleaching Powder.
3. Chlorination
4. Ozonation.
16. Boiler troubles
• Boilers are used for the treatment of water in industries.
• Due to the treatment boiler troubles are caused. They are:-
1. Scale and Sludge.
2. Caustic embrittlement.
3. Boiler corrosion.
4. Priming & Foaming.
17. Internal treatment for Boiler Troubles
• There are three types of Internal treatments for boiler troubles.
1. Calgon conditioning.
2. Phosphate conditioning.
3. Colloidal conditioning.
19. Reactions for ion exchange process
• At Cation:-
2RH+ + Ca2(Hard Water) R2Ca2+ + 2H+
2RH + Mg+2(Hard Water) R2Mg2+ 2H+
• At Anode:-
2ROH- + SO4^2-(Hard Water) R2SO4^2+2OH-
2ROH- + Cl-(Hard Water) R2Cl-+2OH-
20. Nalgonda Technique of Defluorination of
water
• National Environmental Engineering Research Institute (NEERI) has came
up with a Technique called Nalgonda Technique in 1974.
• Nalgonda Technique involves addition of Aluminum, salts, lime and
Bleaching Powder followed by rapid mixing, Flocculation, Sedimentation and
disinfection.
• Allum is added to water to start Flocculation
Al2(SO4)3+18H2O 2Al+3+3SO4+18H2O
22. concentration cell - cell based on emf
generated from difference in
concentration
•uses same substance
•will operate until concentration equal
•use Nernst equation to figure out
•emf of voltaic cell decreases as it
discharges
23. battery - portable, self-contained
electrochemical power source w/ 1 or more
voltaic cells
•use multiple voltaic cells >> greater voltage
•primary cells - can’t be recharged
•secondary cells - can be recharged from
external power source
24. •lead-acid battery - 2V battery w/ lead dioxide as
cathode and lead anode
• 6 strung together in 12-V automotive battery
• can be recharged
•alkaline battery - most common primary battery
• manganese oxide and graphite mixed in
cathode, zinc anode
• emf of 1.55
25. •nickel-cadmium (nicad) battery - most common
rechargeable battery
• environmental hazard, increases weight of
batteries
•nickel-metal-hydride (NiMH) battery - uses alloy
for anode
•litium-ion (Li-ion) battery - has higher energy
density than nickel-based batteries
26. • fuel cells - uses conventional fuels, not batteries (not self-
contained)
• most promising system uses hydrogen/oxygen, forms
water as only product
corrosion - metal converted to unwanted compound due to
environment
•rusting - forms Fe2O3 * xH2O from iron/oxygen
• rust usually deposits at cathode (largest supply of
oxygen)
•paint/metal coatings added to protect against corrosion
27. • galvanized iron - zinc layer added on to iron
•zinc gets corroded before iron
• sacrificial anode - oxidized first to protect
another cathode
electrolysis - nonspontaneous redox reactions
started by outside energy source
•electrolytic cell made of 2 electrodes in
molten salt or solution
•electrolysis of molten salts needs high
temperatures
•inert electrodes - serve as surface where
oxidation/reduction occur
28. •A electroplating - uses electrolysis to
deposit thin metallic layer on another
metal
•ctive electrodes - participate in
oxidation/reduction process
31. POLYMERS
• Polymers are macromolecules formed by linking together of a large
number of small molecules called monomers. The polymers are
giant molecules with high molecular masses. For example, the
monomer ethylene gets linked with many other ethylene molecules
to form polyethylene, or large number of vinyl chloride molecules
combines to form polyvinyl chloride.
• The single repeating unit is called as monomer, and the resultant
high molecular weight compound is called as polymer.
34. POLYMERS
• On the basis of this physical property, the polymers with high
degree of polymerization are known as high polymers while those
having comparatively low degree of polymerization are known as
oligopolymers. The molecular weights of polymers are generally in
the range of 5000 to 200,000. Hence, these are also known as
macromolecules.
• The total number (n) of single monomer units combined together
to form a polymer is known as degree of polymerization (DP). DP
affect physical properties of polymers.
35. CLASSIFICATION
• i) Based on source:
• a) Natural: e.g starch, cellulose, protein
• b) Semi synthetic: Nitro cellulose
• c) Synthetic: Polythene, polyvinyl chloride
36. CLASSIFICATION
• ii) The nature of monomer
• (a) Homo-polymers: A polymer containing identical monomers.
• A-A-A-A
•
• (b) Co-polymers are the compounds formed by two different small
molecules. For example in polystyrene butadiene. One molecule of
butadiene combines with one molecule of styrene. The product
obtained acts as a monomer to get the polymer.
• A-B-A-B-A-A-B
37. • iii) On the basis of arrangement of monomeric units in polymer, these are
named as linear, branched or cross — linked (three dimensional
structures),
• Some examples of linear high polymers are rubber,
• polyethylene, cellulose, polyvinyl acetate
• Polyethylene may also have branched chains.
• The vulcanised rubber is the best known example of cross-linked
polymers in which -S-S- cross links are joined irregularly. Due to cross
linking polymer structure becomes three dimensional cross linked or
network polymer. This makes the polymer very hard and rigid.
40. CLASSIFICATI
ON
• iv)Based on atoms- If the main chain of the polymer is of same atoms, it is known as homo-
chain polymers while if is of different atoms it is known as hetero polymer.
• e.g. -C-C-C-C-C- Homochain polymer
• -C-O-C-O-C-O- Heterochain polymer
• v) Co-polymer is named as regular or irregular on the basis of arrangement.
• e.g. -A-B-A-B-A-B-A-B-A- Regular
Irregular
—A.—B—A—B—A—B-A
• -A-B-B-A-B-A-A-B-B-
•
•
•
•
•
Linear co-polymer
Branched chain homopolymer
41. CLASSIFICATION
• If co-polymer chain possesses relatively long sequence of like
monomers, it is called as block co-polymer where as if co-polymer
possesses branched structures in which the monomer segments are
not in same sequence on branch and backbone, it is known as graft
co-polymers.
• vi) Based on effect of heat polymers are of two types
• Thermoplastics and Thermosetting
44. CLASSIFICATION
• vii) Polymers are also classified on the basis of configuration of
macromolecule known as Tacticity of polymers n following ways
• a) Isotactic polymers
• In isotactic, the head to tail configuration in macromolecule
with respect to functional groups is iso, i.e. all the functional groups
lie on the same side of the chain.
45. CLASSIFICATION
• b) Atactic polymers
• In atactic, the head to tail configuration is random i.e. the functional
groups are arranged randomly.e.g polypropylene
• c) Syndiotactic polymers
• Arrangement of side group in alternating fashion is called
syndiotactic polymer. e.g gutta percha
46. CLASSIFICATION
• b) Atactic polymers
• In atactic, the head to tail configuration is random i.e. the functional
groups are arranged randomly.e.g polypropylene
c)Syndiotactic polymers
• Arrangement of side group in alternating fashion is called
syndiotactic polymer. e.g gutta percha
48. CLASSIFICATION
• Vii-These are examples of homo-organic polymers. Other examples
of organic polymers are polysaccharides, proteins, DNA, viii) On the
basis of chemical composition, the polymers are also called either
organic or inorganic polymer. Generally in organic polymers, carbon
with or without N, S, O, forms the skeleton while in inorganic, other
elements form the skeleton.
• e.g Polyethylene., [ - - - - H2 C - CH2 ------)
• e.g. Polysilanes
• RNA etc. Man made organic polymers include PVC, PP, PVA, PF,
UF, polyesters, polyamides, polyurethanes, synthetic rubbers etc.
49. CLASSIFICATION
• Inorganic polymers are those in which atoms other than carbon
form the skeleton of polymer. Polysiloxanes or polytitoxane0 are the
examples of polymers where side chain may be of organic nature.
They are also known as elemento-organic or hetero-organic
polymers. Polysilanes are purely inorganic in nature. Other
examples of this class are MgO polymer or hydrogen borons.
•
•
[- - -Mg -O-Mg-O-Mg---]
Magnesium oxide polymer.
•
51. POLYMERIZATION
•The reaction of monomers to form a polymer is
known as polymerization. The polymers are formed
mainly by
•i) Addition polymerization (Chain polymerization).
; ii) Condensation polymerization (Step
polymerization).
•iii)Copolymerization
52. POLYMERIZATION
;
• I) Addition or Chain Polymerization-
• The word chain indicates elongation of carbon skeleton to form a polymer. Generally such a polymerization involves the
(C = C) link in monomer. The double bond breaks and as a result two single bonds on either side of each carbon are
formed and thereby elongation of carbon chain continues. The product of this type of polymerization is exact multiple of
monomer number, having no by-product or loss of any molecule.
Thus,
• a. Addition polymerization is undergone by monomers having C = C linkage, e.g.
• ethylene, vinyl chloride, propylene, butadiene, styrene etc.
• b. The rate of reaction is very high.
• c. The polymerization reaction involves three steps such as
• a) Initiation.
• b) Propagation or branching and
• c) Termination.
