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CHAPTER 11

INDUSTRIAL INORGANIC CHEMISTRY

(A) GLASS After studying this chapter you

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Note

Glass is transparent for visible radiation but not for infra red rays.

MANUFACTURE OF COMMON GLASS

Raw Materials

2 3

3

2

Know this

Manufacturing Stages

Melting

3 2 3 2

2 3 2 2 3 2

Activity 11.1

Observe a cheap used thick medicine bottle carefully. It has a wavy

structure and inner layer is not uniformly set. It is because such glasses are

not annealed properly. Spectacle glass is annealed for more than 8-10 hours.

There is proper alignment of molecules in this type of glass.

ii) Shaping

Know this

iii) Annealing

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annealing

Know this

To remove the air bubbles in glass, borax or aluminium powder is added to

the glass and heated slowly. The air bubbles escape from the glass in this

process. Aluminum powder/Borax settles at the bottom and hence it can be

easily separated.

iv) Finishing

Activity 11.2

The sodium content of the sodium silicate present in glass is responsible for this.

Properties of glass

Glasses are widely used because of the following properties :

3

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OBSERVE

Etching of glass

that reacts with glass. With this acid glass articles are self decorated. The

part which is to be decorated is made to react with the acid. This is called

etching of glass.

Activity 11.3

Immerse a glass bottle in a vessel containing water. Heat the vessel slowly.

The bottle does not break even if the water begins to boil. Why?

Fun

Immerse a glass test tube in a mixture of acetone and chloroform in suitable

the solution. This is because of the almost same refractive index of glass and

COLOURED GLASS

OBSERVE

Note

NANO TECHNOLOGY AND GLASS

Recently Prof. C.N.R. Rao of J.N.C.A.S.R. (Jawaharlal Nehru Centre for

Ratna. He has published many research papers. One of his research areas is

Nano technology. Nano means particle size of 10-9 m. Nanotechnology is one

of the most developing research areas in science.

The history of Nano materials can be found during the Roman period. Even at

that time, colloidal metals were used to dye glass.

Romans were skilled at impregnating glass with metal particles to achieve

variety of effects.

Clearly, the ability to synthesize nanocrystals preceded the understanding of

the nanoscale phenomena.

Think

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Activity 11.4

Take around 100 cm3 of

water in a 500 cm3 beaker.

Immerse an empty test tube

You will be surprised to see the

shiny surface of test tube inside

the water as if surface is

silvered. Fill test tube with

water the shiny surface

disappears. Reason out why?

TYPES OF GLASSES

1. Soda - lime glass

Use :

Think

2. Potash lime/hard glass/Bohemian glass

Use :

3. Lead glass / Flint glass

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Use :

OBSERVE

4. Borosilicate glass / Pyrex glass / Jena glass

Use :

5. Safety glass

OPTICAL FIBRE

Recall

Optical fibres have two transparent layers of different refractive

indices. The outer layer has higher refractive index than the inner layer.

you state the condition?

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Note

Communication using electron is termed Electronics. Communication using

Consider the following merits.

Exercise

I. Four alternatives are given to each of the following incomplete

statement / question. Choose the right answer:

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3 2

3 2

3 3 2

II. Fill in the blanks with Suitable words

III. Match the following

A B

IV. Answer the following

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(B) CERAMICS

After studying this chapter you

Note

Water which takes the shape of pot is responsible for shaping the pot along

with clay.

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Note

Dishes made out of glazed clay of

China are used in laboratories and they

are known as China dish. They are brittle

but they are heat resistant and non

corrossive to chemicals.

Find out

What is the meaning of English proverb Bull in a china shop?

Think

Manufacture

Raw Materials used

Know this

Recall

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Think

Note For easy shaping of objects kaolinite and bentonite are ideal.

Know this

Feld spar :

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NoteWater kept in porcelain container will not get cooled, indicating the ab-

sence of holes.

Know this

Activity 11.5

Take two small pots of identical shape and size. Smear the paint the

surface thoroughly in the case of one of the pots.

Surprisingly unpainted pot will have relatively cooler water. This cooling

effect is due to the evaporation of water through the pores, in case of

unpainted pot. Painted pot has no holes and hence no evaporation

through wall of the container and hence no cooling.

Think

Find the reason

Activity 11.6

Collect lemon juice in ceramic cup and metallic cup seperately and keep

it for about an hour. The juice kept in metallic cup will taste differently why?

Know this

Think

Activity 11.7

In the musical instruments like Ghatam and

Jalatarang, clay and ceramic materials are

used. They can be made sonorous like metals.

Take eight ceramic cups of same thickness but

Fill water upto half of the each cup. Take

a long wooden stick and strike each of the cup.

Make variation in stroke and create musical note.

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Exercise

I. Answer the following questions

II. Fill the table with suitable words

Sl.No. Additive Advantages

III. Fill in the blank with suitable answer

Sl.No. Uses of ceramics Reason

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(C) PAPER

After studying this chapter you

Know this

Do you Know

OBSERVE

si

Know this

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1. Pulping

2. Mixing additives

Note

Additives are not used in making blotting paper.

3. Drying

4. Finishing

Activity 11.8

Collect the information about Gloss paper.

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Activity 11.9

news paper strip

glazed paper strip

dilute potassium

permanganate solution

Take about 10cm3 of

dilute potassium

p e r m a n g a n a t e

solution in a100 cm3

beaker. Dip strips of

paper and glazed

paper with the help of

clips and stand.

Observe the rise of

patassium permanganate solution level in each paper samples. In

which paper strip the level of potassium permanganate solution level is

Do you Know?

Activity 11.10

Collect the samples of old paper and compare the samples with fresh one.

in the old paper. Guess, why such changes have taken place.

Know this

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Types of paper

Filter paper :

Activity 11.11

Take a dip tea bag. Remove the tea powder. Observe the bag with a convex lens. Hold the

Tissue Paper :

Wax paper

Card board paper :

Think

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How is waste paper recycled? Collect information

The future of paper

Exercise

I. Fill in the blanks with suitable answer

II. Answer the following questions