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Dr
...
G
...
Define hardness of water
...

Hardness can be detected by treating water with soap
...
What are the salts responsible for carbonate and non-carbonate hardness of water?
Carbonate hardness:
Ca (HCO3)2 and Mg (HCO3)2
Non- Carbonate hardness: CaCl2, CaSO4, MgCl2, MgSO4
...
What are the constituents that cause hardness in water? (or) Explain the terms
Carbonate hardness and non- carbonate hardness
...

Non- Carbonate hardness: This is due to the presence of chlorides and sulphates of calcium
and magnesium
...
Explain what is meant by soft water and hard water
...

This is due to the presence of dissolved Ca and Mg salts
...

Water which produces lather readily with soap solution is called soft water
...

5
...

S
...

solution
...

indicator
...
Distinguish between Carbonate (Temporary) hardness (CH) and non - Carbonate (permanent)
hardness (NCH)
...
No Carbonate
hardness

hardness

(or)

Temporary Non carbonate hardness (or) Permanent
hardness
1

1
2
3

It is due to bicarbonates of calcium and It is due to chlorides and Sulphates of
magnesium
...

It can be removed by boiling the water
...

It is also called as alkaline hardness
...
How is hardness of water expressed (or) Bring out the significance of Calcium Carbonate?
Equivalents (or) Why is hardness expressed in terms of calcium carbonate equivalents
...

Significance: it’s molecular weight is whole number and it is the most insoluble salt
...
A water sample contains 73mgs of Mg (HCO3)2 per lit
...

Given:
Amount of Mg (HCO3)2 = 73mgs per liter
Molecular weight of Mg (HCO3)2 = 146
Amount equivalent to CaCO3 = 73x100
-------------- =
146

50mgs/lit

10
...

This complexation by EDTA and EBT with Ca2+ and Mg2+ ions is possible only at pH =8-10 let
can be maintained by this buffer
...
What is mean by permanent hardness of water? Mention the salts responsible for the
permanent hardness of water
...

CaCl2, CaSO4, MgCl2 and MgSO4 are responsible for the permanent hardness of water
...
Define alkalinity
...
The natural alkalinity in water is
imported by the hydroxide, carbonates, and bicarbonates
...
How is alkalinity classified?
Depending upon the anion present in water alkalinity is classified into three types
1
...
Carbonate alkalinity- due to (CO32-)
3
...
How is alkalinity determined?
Alkalinity can be determined by titrimetry using standard acid phenolphthalein and methyl orange as
an indicators
...

(i)
[OH-] + [H+] -------- → H2O
2

(ii)

[CO3]2- + [H+] -------→

[HCO3-]

(iii)

[HCO3-] + [H+] -------→ H2O + CO2

15
...
Scale and sludge formation
...
Priming and foaming (carry over)
...
Caustic embrittlement
...
Boiler corrosion
...
What are scales and sludges?
SLUDGE:
If the precipitate is loose and slimy it is called sludge
...
They have greater solubilities in hot water than cold water
...
Scale are formed by substances like Ca (HCO3)2, CaSO4 and Mgcl2
...
What are the disadvantages of scale formation?
Scales act as thermal insulators
...
Any crack developed on the
scale leads to explosion
...
What is meant by priming and foaming? How it can be prevented?
Priming is the process of production of wet steam
...

Foaming is the formation of stable bubbles above the surface of water
...


19
...

PREVENTION:
Caustic embrittlement can be prevented by
1
...

2
...

3
...
Indicate the reasons for boiler corrosion?
Boiler corrosion arises due to the presence of
1
...

2
...

3
...

21
...

2
Drinking water
1
...
0 to 8
...

2
...
Define softening of water
...
Softening of water can be done in two methods,
1
...
Internal treatment
3

23
...

The soft water produced by lime soda and zeolite process, does not contain hardness
producing Ca2+ and Mg2+ ions, but it will contain other ions like Na+, K+, SO42-, Cl- etc
...

24
...
Highly acidic or alkaline water can be treated by this process
2
...

25
...

RCa + 2HCl ----------------- RH2+ CaCl2
RNa + HCl ------------------- RH + NaCl
Similarly, when the anion exchange resin is exhausted, it can be regenerated by passing a solution of dil
...

R’Cl2+ 2NaOH -----------------------R’ (OH)2 + 2NaCl
...
Give some examples for cation exchange resin
...
Sulphonated coals
...
Sulphonated polystyrene
...
Give some examples for anion exchange resin
...
Cross-linked quaternary ammonium salts
...
Urea – formaldehyde resin
...
How is water demineralised in an ion-exchanger?
When the water containing ions (both anion and cation) are passed through ion exchange colums,
it absorbs all the ions (anions and cations) as shown below
...

30
...

The sand filter consists of a tank containing a thick top layer of fine sand followed by coarse sand, fine
gravel and coarse gravel
...
How is boiler corrosion, due to dissolved oxygen, removed
...

2Na2SO3+ O2-------------2Na2SO4
N2H4 + O2 ------------- N2+ 2H2O
32
...

CO2+ H2O-----------------H2CO3
Carbon dioxide gas is also produced from the decomposition of bicarbonate salts present in water
...
What is aeration of water? Mention its purpose
...
The main purpose of aeration is
1
...

2
...

34
...

When the coagulant is added to water, it gets hydrolyzed to form a gelatinous precipitate of coagulant

4

Al (OH)3
...

35
...
It is used only in low pressure
boilers
...

CaSO4+ Na2CO3----------- CaCO3 + Na2SO4
36
...
It is used in high pressure boilers
...

3CaSO4+ 2Na3PO4 -----------Ca 3 (PO4)2+ 3 Na2SO4
37
...

Scale forming substances can be removed by adding chemicals directly to the boiler
...

Examples:
Sodium carbonate and Sodium phosphate
...
CaSO4+ Na2CO3------------ CaCO3+ Na2SO4
2
...
What is calgon conditioning? How is it functioning in water treatment?
Or
What is calgon? What is its use in water technology?
Calgon is sodium hexa Meta phosphate Na2 [Na4 (PO3)6]
...

CaSO4 + Na2 [Na4 (PO3)6] ----------------→ Na2 [Na4 [Ca4 (PO3)6] + 2Na2SO4
→
39
...

1
...

3
...


It should be clear, colourless and odourless
...

It should be free from harmful bacteria and suspended impurities
...
, and poisonous minerals like
lead, arsenic, manganese, etc
...
Hardness should be less than 500 ppm
...
Write briefly on disinfection of water by UV treatment
...

When the water containing bacteria is irradiated by UV light, all the bacteria’s are killed
out
...
This is useful for sterilizing water in swimming pool
...
What are the various stages in the treatment of water for domestic supply?
Sources of water → screening -----→ Aeration -----→ sedimentation ------→coagulation ----→ Filtration -------→ sterilization (or) Disinfection
42
...

When bleaching powder is added to water, it produces hypochlorous acid (HOCl)
...

5

CaOCl2 + H2O -----------→ Ca (OH) 2 + Cl2
→
Bleaching powder
Cl2 + H2O ---------------→ HCl + HOCl
→
HOCl + Bacterias ---------------→ Bacterias are killed
...
What is meant by disinfectant? What is the advantage of using chloramines as a disinfectant?
The chemicals used for destroying the harmful bacteria’s are known as disinfectants
...
It is better disinfectant than
chlorine
...

44
...

1
...
0-8
...

2
...

45
...

Or
What is meant by “reserve osmosis”? How is it applied in the desalination of water?
If pressure in excess of osmotic pressure is applied on the higher concentration side, the solvent
flow is reversed, ie
...

Salt water is taken as higher concentration and water is taken as solvent
...

46
...

Or
What is break-point chlorination? Explain
Break point chlorination is the point at which all the impurities are removed and free chlorine
begins to appear
...
Name some of the membranes employed in reverse osmosis process
...

Example: cellulose acetate, cellulose butrate
...

(ii)
The life time of the membrane is high and it can be replaced within few minutes
...
Name the method which separate both ionic and non-ionic impurities from water?
Reverse osmosis process
...
What are the disadvantages of using ozone in disinfection of
(a) This process is costly and cannot be used in large scale
...


water?

50
...
The life time of the membrane is high, and it can be replaced within few minutes
...
It removes ionic as well as non-ionic, colloidal impurities
...
Due to low capital cost, simplicity, low operating this process is used for converting sea
water into drinking water
...
What is blow-down operation?
Blow-down operation is a process of removing a portion of concentrated water by
fresh water frequently from the boiler during steam production
...
What are the advantages of ion-exchange process
...

(ii) The equipment is costly and more expensive chemicals are needed
...
What is it necessary to chlorinate drinking water supply beyond break point?
It is necessary to chlorinate drinking water supply beyond break point because at that point only
all the impurities are destroyed and free chlorine begins to appear
...
Define desalination
...
The water containing dissolved salts with a peculiar salty or brackish taste is called brackish
water
...
Draw the structure of EDTA
...
Demineralised water is a soft water but soft water is not a demineralised water justify?
(Or)
How will you compare the soft water and demineralised water?
The soft water produced by zeolite process does not contain hardness producing Ca2+ &Mg2+ ions
...
on the other hand, demineralised water does not
contain both anions & cat ions
...

57
...
The
functional groups attached to the chains are responsible for the ion- exchanging properties
...
What is cation exchanger and anion exchanger?
Materials capable of exchanging cations are called cation exchangers
...
They are capable of
exchanging their H+ ions with other cations of hard water
...
It may be defined as a
polymer containing amine (or) quaternary ammonium groups as integral parts of the resin and equivalent
amount of anions
...
What is deminralisation (or) deionization process?
In this process almost all the ions (both anions and cations) present in the hard water are
removed
...
In the demineralization process, the ions
present in water are removed by ion-exchangers
...


60
...

There by it prevents the formation of scale and sludge in boiler
...

On the other hand, in phosphate conditioning sodium phosphate is added to the boiler
water so that calcium phosphate precipitates if formed
...

Hence, calgon conditioning is definitely better than phosphate conditioning
...
Differences between sludge and scale
...
Hence the excess of sludge
formation decreases the efficiency of boiler
...

Scales are formed by the substances like
Ca(HCO3)2,CaSO4
It is thermal insulator
...
Any crack in the boiler scale
leads to explosion
Sludges formation can be prevented by using Scales formation can be prevented by using
soft water
...

Sludges can be removed by scrapping off with a Scales may be removed by giving thermal
wire brush
...

62
...

Removal of hardness producing salts from the water before feeding into the boiler is called external
treatment
...
What is carbonate conditioning?
Scale formation in this method can be prevented by adding Na2CO3 to the boiler water
...
What are boiler compounds? Mention two different boiler compounds and their action?
The removal of scale forming susbstance by adding chemicals directly into the boiler is called
internal treatment
...

The boiler compounds kerosene tannin, gelatin, agar agar, etc
...

3CaSO4 + 3Na3PO4 --------------→ 3Na2SO4 + Ca3 (PO4)2
→
CaSO4 + Na2CO3 --------------→ Na2SO4 + CaCO3
→
UNIT-II

POLYMERS
1
...

Polymers are macro molecules (giant molecules of higher molecular weight) formed by the
repeated linking of large number of small molecules called monomers
...

2
...
It is represented by the following relationship
...
Explain functionality of a monomer with suitable example
...

S
...

CH2=CH2 (ethylene)

Functionality
-2 (Two bonding sites are due to the presence of
one double bond in the monomer
...


H2N-(CH2)6-NH2
Hexa methylene diamine

-2 (This monomers contains two functional
groups, hence it is a bifunctional monomers)

4
...

It is a reaction between simple polar groups containing monomers with the formation of
polymers and elimination of small molecules like H2O, HCl
...

n H2N-(CH2)6-NH2 + n HOOC- (CH2)4-COOH

Hexamethylene
diamine

Adipic acid

[ HN- (CH2)6-NH- C-CH2- C ]n -

Nylon 6:6 (polyamide)
...
What are additional polymers? Give one example
...
The original monomers molecule, usually, contains one or more double bonds
...

Ex: polyethylene is produced from ethylene
...
What is polymerization?
Polymerization is a process in which large number of small molecules (called monomers) combine
to give a big molecule (called polymers) with are without elimination of small molecules like
water
...
Name the various polymerization
...
What are the various steps of free radical mechanism?
Free radical mechanisms occur in three major steps namely,
1
...
Propagation and 3
...
What is dead polymer?
The product of addition polymerization is known as dead polymer
...
What is copolymerization? Give an example
...

Example: butadiene and styrene copolymerize to give GR-s rubber
...
How is polymerization classified? Give one example for each class
...
addition polymerization
Example : polyethylene is produced form ethylene
...
condensation polymerization
Example : nylon 6;6 is produce form hexamethylene diamine and adipicacid
...
copolymerisation
Example : GR-S rubber is produced from butadiene and styrene
...
Distinguish between additional polymerization and condensation polymerization
...
No Additional polymerization
1
The monomer must have at least one
multiple bond
...

3
Homo- chain polymers obtained
...

Monomers condense to give a polymer
and by products are formed
...
What do you understand by disproportion of polymer chains?
Disproportion is splitting of a polymer chain into two new compounds
...

H
C

C*

H

R

H

Y

H

H

+ *C

C

Y

H

H
R

R

H

C

C

H
+

H

H

C

C

R

Y
H
Unsaturated
macromolecule

Y H
Saturated
macromolecule
(Dead polymers)

14
...

Preparation: it is obtained by the polymerization of adipic acid with hexamethylene diamine
...

• It posses high temperature stability and good abration-resistance
...

15
...

16
...

§ Low heat-resistant and poor ductility
...

17
...

• Classification based on structure
a
...

b
...

• Classification based on usage
a
...
Engineering plastics
...
What are engineering plastics?
Engineering plastics are a group of materials obtained from high polymer resins
...
They are mainly used in load

10

bearing applications, generally to replace conventional materials like metal, wood, glass and
ceramics
...
What are the important applications of high performance plastics?
• They can be used alone or in combination with metals, ceramics or glasses, etc
...
,
20
...

S
...

They are
formed by addition
polymerization
2
...

3
...

Eg: Polyethelene

Thermosetting Plastics
They are formed by condensation
polymerization
They consist of three dimensional network
structure
...

Eg: Bakelite
...
Distinguish between commodity and engineering plastics
...

No
1
...

3
...

5
...

It possesses low mechanical properties
...

It is general purpose plastics
...

It possesses high mechanical properties
...

It is high performance plastics
...
Mention preparation and uses of PVC (Or) write any two uses of PVC
...

I-Step: vinyl chloride is prepared by treating acetylene with HCl at 60-80 °C in the presence
of metal chloride as catalyst
...


Polymerisation
n CH2=CHCl

-[-CH2-CH-]n-

Vinyl Chloride
Cl
PVC

Uses: It is used in the production of pipes, cable insulations, table covers and rain-coats, etc
...
,
11

23
...

(C6H5)2O2

n CF2=CF2

-[-CF2-CF2-]n-

Tetrofluoro ethylene

Uses:

Teflon

•

It is used as a very good electrical insulating material in motors, cables, transformers,
electrical fittings
...

• It is also used for making gaskets, packings, pump parts,tank linings etc
...

24
...

They are used for making electrical insulator, housing apparetus, plugs, sockets, switche
strerilizable transparent containers, cameras, photographic films, hair drier bodies, baby bottles,
safely windows in prison and jewellery shops,etc
...
Give two properties and uses of perlon-U
...

• It is stable than polyamides
...

They are also used in defense, oceanographic research, mountaineering
...
How is Perlon-U prepared?
It is obtained by the reaction of 1, 4- butane diol with 1, 6- hexane di-isocyanate
...
How is PET prepared?
It is saturated polyester, prepared by condensation of ethylene glycol and terephthalic acid
...
Why is Teflon behaving non- sticking?
Since the fluorine atoms are the strong electronegative elements, they tightly bonds with
carbon atoms in Teflon
...
So, Teflon is non- sticky
...
What are elastomers?
Rubber (or) elastomers are non-crystalline high polymers (linear polymers), having elastic and
other rubber – like properties
...
Raw rubber cannot be used why?
• It is plastic in nature, ie
...

• It has large water- adsorption capacity
• It is non polar solvents like benzene and vegetable and mineral oils
...

• It swells and disintegrates gradually in organic solvents
...

31
...
C
32
...

• It possess superior properties like higher yield strength, fracture strength and fatigue life
...

• It possess high corrosion resistance and heat resistance property
33
...

34
...

CH3

CH3
H2
C

C
C
H2

C
H

CH3
H2
C

C
C
H2

C
H

C
C
H2

C
H

35
...
Which are mutually insoluble, differing in form or composition and forming
distinct phases”, such a combination possesses properties different from those of any of its
constituents
...
Write the characteristics of composites?
• They possess higher specific strength and lower specific gravity
...

• They possess better creep, fatigue strength, corrosion and oxidation resistance
...

37
...

• Matrix phase
...

38
...
What are FRPs?
FRPs are fibre reinforced plastics obtained by reinforcing plastics with a high strength fibre
material
...
Explain the properties of FRP
...

Since fibre prevents slip and crack propagation, the mechanical properties of FRP gets increased
...

41
...

Polyester resin, epoxy resin, phenoic resin
...
Name some important FRPs
...

Boron fibre-reinforced plastics
...
Mention important applications of FRPs
...

(ii)FRPs are used in mining industries for making digesters solvent extraction tanks and
filtration tanks
...

44
...

45
...

n

CH2=CH

+

n CH2=CH-CH=CH2
butadiene

styrene

copolymerisation

-CH-CH2-CH2-CH=CH-CH2-

n

styrene-butadiene rubber

46
...

SBR is used mainly for making light duty tyres, belts, floor tiles, gaskets, gum, hoses,
adhesives and electrical insulation
...
What is GR-I rubber?
It is a butyl rubber obtained by copolymerizing isobutylene with 1
...
5% isoprene in
methyl chloride
...
What are the characteristics of butyl rubber?
• Butyl rubber is amorphous under normal conditions
...

•
It has low permeability to gases
...

•
It possesses good electrical insulating property and resistance to heat and abrasion
...
What is a homochain polymer? Give one example
...

−C−C−C−C−C−
Examples: polyethylene, polyvinyl chloride
...
Define degree of polymerization
...

Polymers with low degree of polymerization are known as “oligopolymers” or “oligomers” and
those with high degree of polymerization are known as “high polymers”
...
What are branched chain polymers?
A branched chain polymer forms when a tri functional monomer is mixed in small amounts with
a bifunctional monomer and polymerized
...
What is a heterochain polymer? Give one example
...

−C−C−O−C−C−O−
Examples: terylene, Nylon 6, 6
53
...

The orientation of functional group of a polymer can take place in an orderly or disorderly
fashion with respect to the main chain is known as tacticity
...

• Isotactic polymer
- Cis – isoprene
• Syndiotactic polymer
- Trans – isoprene
• Atactic polymer
- Polypropylene
54
...
The polymer chains are held together by
strong covalent bonds (cross links)
...
What is the role sulphur in the vulcanization of rubber?
The added sulphur combines chemically at the double bonds of different long chain
Rubber springs
...

The extent of stiffness of vulcanized rubber depends on the amount of sulphur added
...
Define adsorption and Adsorbate
...
The adsorption of gas on a solid is sometimes called occlusion
...

2
...

3
...

Adsorbate: the substance which is held on the surface of the solid is called the adsorbate ,
Eg: Ni(s)
Adsorbent: the solid that takes up a gas or solute from the solution is called the adsorbent
15

Eg: H 2(g)
4
...

Chemical adsorption is the one in which the adsorbed molecules are held on the surface of the
adsorbent by chemical bonds (covalent bond or ionic bond) Eg adsorption of H2 on Ni
5
...

Physical adsorption is the one in which the adsorbed molecules are held on the surface of the
adsorbent by weak physical(or)vander walls forces of attraction
...
Adsorption of H2 (or) O2
on charcoal
...
Mention some important characteristics of adsorption
...

(ii)
Adsorption is aiways accompanied by evolution of heat
...

(iv)
Adsorption is a selective process
...
What are the difference between absorption and adsorption?
S
...

Adsorption is a surface phenomenon
...

2
...

Equilibrium is attained easily
...

4
...

more on the surface and less in the
bulk
...
How does chemisorptions differ from physisorption?
Or Write any two differences between chemisorptions differ from physisorption?
S
...

It is caused by intermolecular It is caused by chemical bond
Vander Waal’s forces (weak)
formation (strong)
2
...
cal/mol)
k
...

Adsorption is completely reversible
...

4
...

5
...

Only monolayer adsorption occurs
...
How will you increase the activity of an adsorbent?
Activation leads to increase in the surface area of the adsorbent, which increases adsorption
...

(b) By the subjecting to some chemical reaction on the solid adsorbent
...

(b) By heating of solid adsorbent into superheated steam, now its pores are
opened and adsorption increases
...
Explain the effect of temperature on adsorption
...

Chemical adsorption: It increases with increase in temperature and then decreases
...
Explain the function of activated charcoal with example
...

(ii)
It also adsorbs certain acids like CH3COOH and (COOH)2 present in water,
thereby acid concentration in water decreases
...


16

12
...

Adsorption isotherm
Adsorption isotherm is a relationship between magnitudes of absorption with pressure
...
What is Freundlich’s adsorption isotherm?
The relationship between between the magnitude of adsorption (x/m) and
pressure (p) can be expressed mathematically by an equation known as freundlich
adsorption isotherm
...
Write a suitable equation commonly applied to the adsorption of liquids on solids?
x/m= KC1/n (or) log x/m=logK+1/nlogC
Where ‘k’ and ‘n’ = constants
x= mass of adsorbate
m= mass of the adsorbent
...
Explain the limitation –s of Freundlich’s adsorption isotherm
...

(ii)
The equation is valid only upto a certain pressure and invalid at higher pressure
...

(iv)
Freundlich adsorption isotherms fail, when the concentration of adsorbate is
very high
...
What is langmuir’s adsorption isotherm? How it is mathematically represented?
The relationship between the amounts of gas adsorbed to the pressure of the gas at
constant temperature is known as Langmuir’s adsorption isotherm
...
What are the demerits of Langmuir’s adsorption isotherm?
Langmuir’s adsorption isotherm holds good at lower pressure but fails at high pressure
...

19
...
What is the effect of temperature and pressure on the adsorption of hydrogen gas on charcoal?
Adsorption of H2 on the charcoal is rapid at lower temperature and decrease with increase
in temperature, but the rate of adsorption increases with the increase of pressure
...
What are the effects of increase in temperature and increase in pressure on the adsorption of a
gas on a solid?
(i) Effect of increase in pressure: Adsorption generally increases with increase of pressure
...

(b) Chemical adsorption: It increases with increase in temperature and then decreases
...
How is arsenic poisoning removed from the body?
Colloidal ferric hydroxide is administered, which adsorbs arsenic poison and is removed from
the body y vomiting
...
Define ion- exchange adsorption
...

Example: Water softening using zeolite
...
How is evaporation of water in lake minimized?
Due to scarcity of water during summer a layer of stearic acid is spread over water lakes and
reservoirs
...

25
...

(ii) It helps in the formation of activated complex, where in bonds in the reactants are easily broken
and the products are easily formed
...
Where is ion exchange adsorption applied?
Ion exchange adsorption is applied, where the dissolved ions are exchanged with the ions of the
adsorbents
...

RCa + 2HCl ----→RH2 +CaCl2
RSO4 + 2NaOH-----→ R (OH) 2 +Na2SO4
27
...

• The nature of adsorbent
• The area of adsorbent
• The nature of gas adsorbed
• The temperature and pressure of the gas
28
...

• The nature of adsorbent
• The nature of solute adsorbed
• The temperature
• The concentration of solution
...
List the factors affect the adsorption?
•
•
•
•
•
•
•
•

Nature of gases
Nature and surface area of adsorbent
...

Reversible character of adsorbed gases
...


UNIT- IV
Non-Conventional Energy Sources
1
...
Give an example
...

2
...

(i) A heavy nucleus (U235 (or) Pu239) when bombarded by slow moving neutrons split into two or
more nuclei
...

(iii) Large quantities of energy is produced as a result of conversion of small mass of nucleus into
energy
...
What is nuclear fusion? Give an example
...
Nuclear fusion occurs in sun
...
What is nuclear chain reaction?
A fission reaction where the neutrons from the previous step continue to propagate and repeat the
reaction is called nuclear chain reaction
...
Give any two differences between nuclear fission and nuclear fusion
...
No
Nuclear fission
1
...


Nuclear fusion
It is the process of combination
of lighter nuclei
...


It emits radioactive rays
...


It occurs at ordinary temperature
...

It occurs at high temperature
(>106 k)
...
What is super critical mass and sub-critical mass of U235?
(a) Super Critical mass
If the mass of the fissionable material (U235)is more than the critical mass, it is called
super critical mass
...

7
...

The energy released by the nuclear fission is called fission energy (or)nuclear energy
...

U92235 + n01 ----------------------→ Ba5639 + Kr3694 + 30n1 +Energy
8
...

235
+ 0n1 ----------- → [92U236] ----------- -→ 56Ba140 + 36Kr93 + 30n1
92U
The factors that impeded the nuclear chain reaction are
(i)
Some of the neutrons may escape from the surface to the surroundings
...

9
...

(a) Nuclear fusion reaction
2
2
-------------> 2He4 + energy
...
What are the types of nuclear fission reaction?
The nuclear fission reactions are of two types
...

(ii)
Controlled fission reactions - nuclear reactor
...
What is a nuclear reactor?
The arrangement or equipment used to carry out fission reaction under controlled conditions is
called a nuclear reactor
...
What is light water nuclear – power plant?
Light – water nuclear-power plant is the one in which U235 fuel rods are submerged in water
...

13
...

The substances used to slow down the neutrons are called moderators
...

14
...
What is fissile nuclides and fertile nuclides?
(i) The fissionable nuclides such as U235 & Pu239 are called fissile nuclides
...

16
...

S
...
What are the general components of a nuclear reactor?
1
...
Control rods, 3
...
Pressure vessel, 6
...
Turbine
...
What is Breeder reactor?
Breeder reactor is the one which converts non- fissionable material (U238, Th232) in to
fissionable material (U235, Pu239)
19
...

This solar energy conversion occurs by the following two mechanisms
...
Thermal conversion
...
Photo conversion
...
What is thermal conversion?
Thermal conversion involves absorption of thermal energy in the form of IR radiation
...

21
...

Photo conversion involves conversion of light energy directly into electrical energy
...
What is photo galvanic cell (or) Solar cell?
Photo galvanic is the one, which converts the solar energy (energy obtained from the sun) directly
into electrical energy
...

23
...

1
...

2
...
Solar energy can be stored in Ni- Cd batteries and lead-acid batteries
...
Solar cells can be used to drive vehicles
...
Solar cells, made of silicon, are used as a source of electricity in space craft and satellite
...
What are fuel cells?
Fuel cell is a voltaic cell, which converts the chemical energy of the fuels directly into electricity
Without combustion
...
In these cell,
the reactants, product and electrolytes pass through the cell
...

25
...
What are the applications of H2-O2 fuel cell?
1
...

2
...

27
...
Wind energy recovered from the force of the wind is called wind energy
...
The energy possessed by wind is because
of its high speed
...

28
...

• Wind forms located on the migratory routs of birds will cause hazards
...
Write any four methods adopted for the harnessing wind energy
...
What are thermonuclear reactions?
Nuclear fusion is supposed to be responsible for the enormous large energy of starts and
stellar bodies
...
Such nuclear reactions are therefore called as thermonuclear reactions
...
What is the basic principle used in hydrogen bomb?
The hydrogen bomb is the result of thermonuclear reactions
...
But the energy released during
fusion brought about by this method is not controllable
...
What is the basic principle of solar cells?
Solar cells are made of thin wafers of semiconductor materials like silica or gallium
...

33
...

Primary cells: they are unchangeable cells because the active materials consumed during the
discharge process cannot be regenerated by passing electric current
...

Secondary batteries: they are known as chargeable batteries because the active materials
consumed during the discharge can be regenerated back into their original form by passing
electric current
...
Explain charging and discharging characteristics of a battery?
Discharging: It is an electrochemical process by which a battery delivers current to an external
circuit at the cost of the consumption of electrode materials is known as discharging
...

35
...

Anode
Negative plate: Pb-Sb grid filled with spongy lead
...
4%H2SO4(sp
...
25-1
...
C)
Separator
Nylon cloth
Container
Polypropylene (pp)
Cell representation
Pb,PbSO4/H2SO4 (21
...
Mention the various components of nickel cadmium batteries
...
KOH/Ni,Ni(OH)3
37
...

38
...
What are the merits of wind energy ?
o It does not cause any air pollution
...

o It is renewable
o It doesn’t cause any pollution
At anode:
At cathode:

40
...
The loss in mass get converted into energy according Einstein’s equation,
E=mc2
41
...

In a nuclear fusion reaction, two protons(hydrogen atoms) combine to give a helium with liberation of
large amount energy
2
2 ----------------- →
4
2He
1H + 1H

42
...
Thus,
A CELL
: Contains only one anode and cathode
...


43
...

(ii)
It should have long life both when it is being used and when it is not used
...

44
...
(or)What are primary cells?
Primary cells are cells in which the electrode and the electrode reactions cannot be reversed by
passing an external electrical energy
...
Therefore they are not chargeable
...
What are secondary cells?
Secondary cells are cells in which the electrode reactions can be reversed by passing an
external electrical energy
...
These are also called storage cells (or) Accumulators
...
Write the overall equation for the reaction taking place in an alkaline battery
...
What are the advantages of alkaline battery over dry battery?
(i)
Zinc does not dissolve readily in a basic medium
...

(iii)
Alkaline battery maintains its voltage as the current is drawn from it
...
Write the cell representation of lead storage cell
...

49
...

The cell can be recharged by passing electric current in the opposite direction
...
As a result Pb is deposited on anode and PbO2 on the cathode
...

The net reaction during charging is
2PbSO4(s) +2H2O+Energy -----------------------> Pb(s) +PbO2(s) +2H2SO4 (eq)

50
...

Pb(s) +PbO2(s) +2H2SO4 (aq) ------------------- 2PbSO4(s) +2H2O+Energy
...
What are the applications of lead acid storage cell?
(i)
lead storage cell is used to supply current mainly in automobiles such as cars
buses trucks etc
...
,
52
...

Cd/ Cd (OH) 2//KOH (aq)/NiO2/Ni
53
...

(ii)
It has longer life than lead storage cell
...

Disadvantage
It is more expensive than lead storage battery
...
How are anodic and cathodic electroactive materials made in Ni-Cd battery?(or)
How is NICAD battery constructed?
Nickel-cadmium cell consists of a cadmium anode and a metal grid containing a paste of NiO2
acting as a cathode
...

55
...

Cathode: cathode is a metal grid containing a paste of NiO2
...

56
...

The lithium battery consists of a lithium anode and a TiS2 cathode
...
The electrolyte (polymer) permits the passage of
ions but not that of electrons
...
What are the advantages of Li-S battery?
• Li-S battery has light weight unlike the lead acid battery
...

• It is used in electric cars
...
List any two advantages of lithium batteries
...

Since Li has the most negative E0 value it generates a higher voltage than the other
types of cells
...

This battery can be made in a variety of sizes and shapes
...
What are the advantages of using lithium as anode in batteries?
• Since Li has the most negative E0 value it generates a higher voltage than the other
types of cells
...

• Its cell voltage is high 3
...


UNIT – V
ENGINEERING MATERIALS
1
...
(or)give two examples for neutral
refractory
...
They are used for the construction of lining in furnaces, kilns etc
...

(ii)
Basic refractories: magnetite, dolomite
...

2
...

(i)
It should be infusible at the operating temperature
...

(iii)
It should resist the abrading action of flue gases flames etc
...

3
...
It is expressed in terms of pyrometric cone
equivalent
...
What is meant by pyrometric cone equipment (PCE) of a refractory?
Pyrometric cone equipment is the number which represents the softening temperature of a
refractory specimen of standard dimension and composition
...
Name the stages in the manufacture of refractory
...
What are the important uses of refractories?
• Refractories are mostly used for the construction of the lining of the furnaces,
tanks,converters,kins,crucibles,ladles,etc
...
,
7
...
5 or 1
...
The temperature at which the refractory deforms by 10% is called
refractoriness under load (RUL)
...

8
...

(ii)
They are inert to the action of gases like CO2, H2 and natural conditions
...

9
...

Neutral refractories and refractories are made from weakly acidic and basic materials like
carbon, chromite, zirconia, etc
...

Examples: Graphite, Chromite, Zirconia, Carborundum refractories
...
Name any one of the natural refractories and its synthesis
...
They are prepared by mixing zirconite mineral(ZrO2)
with colloidal zirconia or alumina as binder and finally heated to 17000° C
...

11
...

12
...

• To classify the refractories
...

• To check whether the refractory can be used at the particular servicing temperature
...
Why is silica bricks expand on heating?
Silica bricks expand on heating due to the transformation of one form to another forms
...

Quartz ----------→ Tridymite ------------------→ Cristobalite
(Crystalline)
(α - form)
(β - form)
14
...

It is defined as the ratio of its pore volume to the bulk volume
...
What is meant by dimensional stability? Mention their types
...

These dimensional changes are of two types
...

16
...

Thermal spalling can be decreased by
(i)
Using high porosity, low co-efficient of expansion and good thermal conductivity
refractory
...

(iii)
By modifying the furnace design
...
Name two refractories which should not be place in direct contact with fire clay
refractory
...

18
...

Abrasives are hard substances used for polishing, shaping, grinding operations
...

Natural abrasives - diamond, quartz, corundum, emery
Artificial abrasives - Silicon carbide, boron carbide, alundum
...
What are soft abrasives?
Abrasives having their hardness 1-4 in Moh’s scale are known as soft abrasives
...
What is abrasive power?
It is the strength of an abrasive to grind away other materials
...

21
...
The harder the abrasive
quicker will be its abrading action
...
Explain moh’s scale for different abrasives
...

23
...

• To clean the surface prior to coating abrasives powders are used
...


25

•

To prepare smooth wood, metal and plastic surfaces, abrasives paper is used: eg alumina
silicon carbide
...

24
...

• It should be very hard
• It should be chemically inactive
...

• It should posses high refractoriness
• It should have high melting point
25
...

• As abrasive paper or cloth
...

26
...
It consists of 55-75% crystalline alumina
20-40% magnesite and 12% other minerals
...

27
...
C
SiO2 + 3C -----→ SiC + 2CO ↓
28
...

It is pure crystalline carbon
...
It is
chemically inert and not affected by acids or alkalis
...

29
...
C
...

30
...
C
2700°C
2B2O3 + 7C -----------------→ B4C + 6CO↑
Properties
• Its hardness is 9 on mho’s scale
• It is light weight and black coloured compound
...

• It resists oxidation much better than diamond
...
What is carnet? Give its uses
...
Its hardness ranges from
6-7
...

Uses : It is used in making abrasives paper and abrasive cloth, and also in glass grinding and
polishing metals
...
Explain the uses of alundum
...

It is also used in the manufacture of abrasive wheels
...
Define the terms “Lubricant” and “Lubrication”
...

34
...

• It prevents the direct contact between the moving surfaces and reduces wear, tear, and
surface deformation of the concerned parts
...

26

• It reduces the frictional heat and thus prevents the expansion of metals
...
Mention some important characteristics of a lubricant
...

• A good lubricant should have higher flash and fire points than the operation temperature
...

• A good lubricant should not corrode the machine parts
36
...

(or)
How are lubricants classified? Give one example for each class
...

1) Liquid lubricants 2
...
Solid lubricants 4
...

emulsions
Cutting emulsions, cooling liquids
37
...

1
...
Polyglycol ethers
...
What are extreme pressure additives ? Give examples
...

Eg
...

39
...

Oiliness is the capacity of a lubricating oil to stick on to the surface of the machine parts under
heavy load or pressure
...
Veg
...

Oiliness can be improved by adding additives such as oleic acid, stearic acid, etc
...
What are viscosity index improvers? Give examples
...

Eg
...

41
...

Viscosity index is defined as the average decrease in viscosity of oil per degree rise in
temperature between 100 F and 210 F
...
What is the significance of pour point of a lubricant?
Most of the petroleum based lubricating oils contain dissolved paraffin wax and asphaltic
impurities
...
So the cloud and pour points indicate the suitability of the lubricants in cold condition
...

43
...

Pour point depressants are substances used to prevent separation of wax from the lubricating oil
...
Phenols, polyalkyl benzene
...
What should be the flash point of a good lubricant? Give reason
...

Reason
...

45
...


27

Flash point: It is the lowest temperature at which the oil gives off enough vapour that ignites for
a moment, when a small flame is brought near it
...
Generally the fire point 5-40 C higher than
flash point
...
What are greases? How are they classified?
Greases are semi-solid lubricants obtained by thickening of lubricating oil by the addition of
metallic soap
...

47
...

Lithium based grease is prepared by thickening of petroleum oil with lithium soap
...

It is a water and heat resistant
...

Uses:
It is used at lower temperatures for lubricating engines
...
Mention the differences between soda-base and lime –base greases
...
What are greases? How are they prepared?
Greases are semi-solid lubricants, obtained by thickening of lubricating oil by the addition of
metallic soap
...
What are solid lubricants? Mention their application
...
Solid lubricants are
also used where oils, and greases cannot be used
...
Graphite, MoS2
...

51
...
Under what conditions extreme pressure lubricant is used
...

Under the conditions of high load (high pressure) and high speed, where more heat is generated,
extreme pressure lubricants is used
...
Explain the lubrication action of graphite
...
Since dthe
distance between the adjacent layers is high (3
...
As a result graphite’s possess very low co-efficient of friction
...

54
...
Since the distance between the
adjacent layers is high and posses very low co-efficient of friction, it acts as a lubricant
...

28

55
...
They are consider as intermediate forms of diamond and graphite and
are used as industrial abrasives
...

56
...

• Quartz is crushed to suitable size and glued on thick paper to produce abrasive paper
Quartz pebbles are used for grinding pigments in ball mills
...
What are nanomaterials? Mention any two of their characteristics properties
...

Characteristics :
Nanomaterials are very strong and withstand extreme strain and tension
...

58
...
When graphite sheets are rolled into a cylinder, their edges joined and from
carbon nanotubes i
...

59
...
single- walled nanotubes (SWNTs)
2
...
Mention the important forms of SWNTs
...
It is one- atom thick having a diameter of 2 nm and a
length of 100µm
...

1
...

2
...

3
...

61
...

Carbon nanotubes can be made by any one of the following three methods
...
Pyrolysis
2
...

3
...

4
...
How are CNTs used in the fuel cell?
SWNTs is used in the form of place or paper as anode in the fuel cell
...
What is the main requirement for fuel cell containing CNTs
...

64
...

1
...

NiO -------------------→ Ni
2
...

AlCl3 --------------------→ Al
65
...

Carbon nanotubes are synthesized by the pyrolysis of hydrocarbons such as acetylene at about
700
...

66
...

67
...

1
...

29

2
...

3
...

4
...

5
...
Under what operating conditions would you use lubricating oils and solid lubricants
...

Solid lubricants - it is used under high load high temperature
...
Distinguish between acidic and basic refractoriness
...
no
1
2

Acidic refractories
It is made of acidic materials like
alumina &silica
They are easily attacked by basic
materials

Basic refractories
It is made of basic materials like CaO,
MgO etc
...
Under what situations solid lubricants are used?
i) where the operating temperature and load is too high
...

iii) where combustible lubricants must be avoided
...
N
...
P INSTITUTE OF TECHNOLOGY, COIMBATORE – 48
DEPARTMENT OF CHEMISTRY
(PART- B)
UNIT- I - WATER TECHNOLOGY

1
...
Describe the principle and method involved in the determination of different types
and amount of alkalinity of water
...
How is internal treatment of boiler water carried out using phosphate, carbonate
and calgon
4
...
Explain in detail the demineralization process for softening of water
...
Explain the softening of water by deionization process
...
How is temporary and permanent hardness of water determined?
8
...

9
...
6mg/litre
of magnesium chlorideMgCl2, 2
...
4mg/litre of magnesium bicarbonate Mg (HCO3)2 and 6
...

10
...
200ml of a sample of water required 22ml of N/50 H2SO4 using methyl orange as
indicator but did not give any colourination with phenolphthalein
...
of CaCO3
12
...
Discuss in detail about the break point chlorination
...
Explain the various types of polymerization with suitable examples
...
Explain the mechanism of free radical polymerization
...
What are the drawbacks of raw rubber? How to improve the properties of rubber?
Explain the process of vulcanization of rubber
...
Write a note on the preparation, properties and uses of nylon 6:6, nylon6, and
nylon11?
5
...
Discuss the synthesis, properties and uses of poly carbonate and Butyl Rubber
7
...

8
...
Distinguish between addition and condensation polymerization
...
Explain condensation polymerization taking one example
...

11
...
Derive the Langmuir and Freundlich adsorption isotherm and discuss the effect of
pressure on the isotherm
...
Explain the role of adsorption in catalysis using an appropriate example
...
Briefly explain the factors which influence adsorption of a gas on a solid
...
Discuss the role of adsorbents in pollution abatement?
5
...
Define adsorption isotherm and explain the types of adsorption isotherm
7
...
Explain in detail about Physical and chemical adsorption
...
Mention the factors which influence adsorption of a solute on a solid
10
...
illustrate how the ion exchange adsorption is useful in the demineralization of
water
12
...
Explain the
different types of adsorption isotherms of gases on solid
...
What is a nuclear reactor? Describe the components of a light water nuclear power
point with a neat diagram
...
What is Breeder reactor? Explain the principles with an example
...
Describe the construction and working of H2 – O2 fuel cell
...
Explain the construction and working of NICAD battery with cell reaction
...
What is reversible battery? Describe the principle, construction and working of
Lead – storage battery with reaction
6
...

7
...
Give an account of solar cells and its application
...
Explain the following terms: Wind energy, Nuclear fusion and primary battery
10
...
Describe the conversion of solar energy into electrical energy
...
Discuss the characteristics of the reaction when uranium undergoes nuclear
fission
...
Explain the construction and working of any one secondary battery with cell
reaction

UNIT- V – ENGINEERING MATERIALS

1
...

2
...
What are abrasives? How are they classified? Give examples for each category with
their important properties
...
Discuss the structure, properties and uses of Graphite
...
Define and signify flash, fire point
...
Give a brief account of PCE test
7
...

8
...
Give an account of the important properties of lubricating oil
...
Explain the properties and applications of carbon nanotubes (CNTs)
11
...
Name the additives for lubricating oils
...
Explain the mechanism of lubrication
...
Explain the terms: viscosity index, dimensional stability and Porosity
15
...
Explain the general methods of manufacture of refractories

---