Balbharti Maharashtra State Board Class 9 Science Solutions Chapter 14 Substances in Common Use Notes, Textbook Exercise Important Questions and Answers.

Class 9 Science Chapter 14 Substances in Common Use Textbook Questions and Answers

1. Fill in the blanks.

a. The number of molecules of water of crystallization in washing soda is …………….…. .
b. The chemical name of baking soda is …………….…. .
c. …………….…. is used in treatment of hyperthyroidism.
d. The chemical name of Teflon is …………….…. .
Answer:
a. 10
b. Sodium bicarbonate
c. Iodine -123
d. Polytetra fluoroethylene (C₂F₄)_n

2. Match the pairs

Answer:
(1 – c),
(2 – a),
(3 – d),
(4 – b)

3. Write answers to the following

a. What is meant by radioactivity?
Answer:

b. When is said to be the nucleus unstable?
Answer:

c. Which diseases are caused by artificial food colours?
Answer:
Diseases like ADHD (Attention Deficit Hyperactivity Disorder) can affect children due to excessive consumption of foods with added food colours.

d. Where in the industrial field is radioactivity used?
Answer:
Industrial field Radiography

Measurement of thickness, density and level

Luminescent paint and radio luminescence:

Use in Ceramic articles:

e. Write down properties of teflon.
Answer:
Properties of teflon :

f. What type of colours will you use to celebrate ecofriendly Rang Panchami? Why?
Answer:

g. Why has the use of methods like Teflon coating become more common?
Answer:
The use of methods like Teflon coating became more common because of following properties of teflon:

4. Give a scientific explanation

a. Bleaching powder has the odour of chlorine.
Answer:

b. The hard water of a well becomes soft on adding washing soda to it.
Answer:

c. Soap forms a precipitate in hard water.
Answer:

d. The particles of powder are given an electric charge while spraying them to form the powder coating.
Answer:

e. The aluminium article is used as an anode in the anodising process.
Answer:

f. When the radiation coming out from certain radioactive substance is passed through an electric field, marks are found at three places on the photographic plate placed in its path.
Answer:
(i) When the radiation coming out from certain radioactive substance is passed through an electric field, marks are found at three places on the photographic plate placed in its path. This is because the radiation coming out from radioactive substance are of three types Alpha rays, Beta rays and Gamma rays.

(ii) The rays which get deviated slightly towards negatively charged plate are called alpha rays. They get deviated towards negatively charged plate because they are made of positively charged particles, called as alpha particles (He++).

(iii) The rays which get deviated substantially towards the positively charged plate are called beta rays. They get deviated towards a positively charged plate because they are made of negatively charged particles called as beta particles (e-).

(iv) The rays which do not deviate at all are called gamma rays. They are uncharged electromagnetic radiation. Hence, marks are found at three places on the photographic plate. (For diagram refer Fig. 14 .2 from Q. 4(3))

g. A certain type of ceramic tiles are fixed on the outer layer of a space shuttle.
Answer:
(i) Each shuttle is covered by more than 24,000 of the six- by six-inch advance ceramic tiles. This tiles withstand high temperatures without decomposing. They are brittle, water-resistant and electrical insulator. Most of the tiles are made of silica fibres, which are produced from high-grade sand (SiO₂).

(ii) Silica is an excellent insulator because it transports heat slowly. When the outer portion of a tile gets hot, the heat takes a long time to work its way down through the rest of the tile to the shuttle’s skin. The tiles keep the orbiter’s aluminium skin at 350 degrees or less.

(iii) The silica fibers are mixed with water and chemicals, and the mixture is poured into molds, which are zapped in microwave ovens at 2,350°C to fuse the silica fibres. Tiles are too brittle to attach to the orbiter directly.

(iv) The shuttle’s skin contracts slightly while in orbit, then expands during re-entry.

(v) In addition, the stresses of launch and re-entry cause the skin to flex and bend. Such motions could easily crack the tiles or shake them off. To keep them in place, workers glue the tiles to flexible felt-like pads, then glue the pads to the orbiter.

5. Write answers to the following

a. Write about artificial food colours, the substances used in them and their harmful effects.
Answer:
(a) Artificial food colour and substances in them.

(b) Harmful effects of artificial food colours

b. What is meant by water of crystallization? Give examples of salts with water of crystallization, and their uses.
Answer:
The exact number of water molecules which are chemically bonded to a molecule of a salt within a hydrated crystalline compound is called as water of crystallization are:

Some substances in our daily use which contain water of crystallization are:

Uses of these salts are as given below:
(i) Alum (Potash alum – K₂SO₄.Al₂(SO₄)₃.24H₂O)

(ii) Borax (Na₂B₄O₇.10H₂O)

(iii) Epsom salt (Magnesium sulphate MgSO₄.7H₂O)

(iv) Barium chloride (BaCl₂.2H₂O)

(v) Sodium sulphate (Glauber’s salt Na₂SO₄.10H₂O)

(vi) Blue vitriol (Copper sulphate CuSO₄.5H₂O)

c. Write briefly about the three methods of electrolysis of sodium chloride.
Answer:

6. Write the uses.

a. Anodizing
b. Powder coating
c. Radioactive substances
d. Ceramic
Answer:
(a) Anodizing : Anodizing is done on aluminum cooking utensils like griddles and cookers.

(b) Powder coating : Powder coating is done on iron objects to prevent rusting. Also, on Plastic and Medium density fibre (MDF) board, to make them highly durable, hard and attractive.

(c) Radioactive substances:
(I) Industrial field:
(i) Industrial Radiography : Internal cracks and voids in cast iron articles and iron solder can be. detected with the help of gamma rays. For this purpose, isotopes like cobalt-60, iridium-192 are used in the radiography camera. This technique is used for detecting flaws in metal work.

(ii) Measurement of thickness, density and level: It is necessary to maintain the required thickness in the manufacture of aluminium, plastic, iron sheets of differing thickness. In the manufacturing process, a radioactive substance is placed on one side and an instrument to measure radiation on the other. The radiation read by the measuring instrument varies with the thickness of the sheet. Material inside a packing can also be examined by the same technique.

(iii) Luminescent paint and radioluminescence:
The radioactive substances radium, promethium, tritium with some phosphor are used to make certain objects visible in the dark, for example, the hands of a clock, and certain other objects. Krypton-85 is used in HID (High Intensity Discharge) lamps while promethium-147 is used in portable X-ray units as the source of beta rays.

Use in Ceramic articles – Luminous colours are used to decorate ceramic tiles, utensils, plates, etc. Earlier uranium oxide was used in these paints.

(II) Field of agriculture :

(III) Medical science:

(d) Ceramic : Pots made by a potter, Mangalore roofing tiles, construction bricks, pottery, terracotta articles are some examples of common ceramic articles that we see around.

7. Write the harmful effects

a. Artificial dye
b. Artificial food colour
c. Radioactive substances
d. Deodorant
Answer:
(a) Artificial dye:

(b) Artificial food colour:

(c) Radioactive substances :

(d) Deodorant:

8. Write the chemical formula Bleaching powder, common salt, baking soda, washing soda
Answer:

9. Explain what you see in the following picture

Class 9 Science Chapter 14 Substances in Common Use Intext Questions and Answers

Can you recall?

Question 1.
What are detergents?
Answer:

Question 2.
What are the important substances that we use in day to day life? For what purposes do we use them?
Answer:
Some of the substances we use in our day to day life and the purpose of using them are as follows:

Toothpaste: for cleaning teeth and maintaining hygienic conditions of mouth.

Soap : for bathing and maintaining hygienic conditions of body.

Natural and artificial fibers : we wear them as clothes to protect our body and many other purposes.

Washing powder: for cleaning clothes. Vegetables, fruits and food grains : they provide us with necessary vitamins, minerals and carbohydrates required for proper functioning of body.

Water : very important for our survival and many other functions of day to day life.

Metals : for making buildings, bridges, roads, vehicles, trains, ships, airplanes, utensils etc.

Acids, bases and salts : used for various purposes, for example, Sodium chloride which is used as common salt, a very necessary ingredient of our daily food without which our food is tasteless.

Question 3.
How are the various substances in day to day use classified from the scientific point of view?
Answer:
The various substances in day to day use are classified from the scientific point of view as elements, compounds, mixtures, metals, non-metals, acids, bases and salts.

Question 4.
Which chemicals and apparatus will you use in the laboratory for making soap?
Answer:
For making soap in laboratory following chemicals and apparatus are used :
Chemicals : Vegetable oil (coconut oil, castor oil, soya bean oil etc.)
Sodium hydroxide (NaOH)
Salt (Sodium chloride NaCl)

Apparatus :
500 ml glass beaker
Burner
Flat glass tray
Knife

Soaps are essential to personal and public health. They safely remove germs, soils and other contaminants and help us to stay healthy and make our surroundings more pleasant. Soaps are made from fats and oils or their fatty acids.

Take about 20 ml of any vegetable oil (coconut oil, castor oil, soybean oil etc.) in a beaker. Put about 30 – 35 ml of NaOH in it and heat and stir the mixture till a paste is formed. Now add a little salt. Stir again and allow the mixture to cool in a flat glass tray, on cooling it solidifies. Take a knife and cut it in soap bars as per the size required.

Question 5.
What are salts?
Answer:

Answer the following questions:

Question 1.
How is it determined whether a substance is acidic, basic or neutral?
Answer:

Question 2.
A sweets shop looks attractive because of the colourful sweets displayed there. Which colours are used in these substances?
Answer:

Question 3.
Make a list of substances in day to day use in accordance with their pH value (O to 14).
Answer:

Question 4.
A doctor gives you medicines when you fall ill. What are the medicines made from?
Answer:

Question 5.
What problems do you get after playing colours on Rang Panchami? Why?
Answer:

Question 6.
Which colours will you use to prevent the occurrence of these problems?
Answer:

Question 7.
What problem do you have on painting the house and furniture?
Answer:

Question 8.
What is the property of Teflon because of which it is used in non-stickware?
Answer:
Following are the properties of teflon because of which it is used in nonstick cookware.

Answer the following questions:

Question 1.
What is the strip shown below? What is it used for?
Answer:
The strip shown is pH metre scale. It is used to determined pH of solutions.

Question 2.
Prepare saturated solutions of given salts and put 2-3 drops of the universal indicator in them and note your observations in the table below:
Answer:

Class 9 Science Chapter 14 Substances in Common Use Additional Important Questions and Answers

Select the correct option:

Question 1.
Baking soda is ………………………… .
(a) non-metallic
(b) metallic
(c) acidic
(d) basic
Answer:
(d) basic

Question 2.
During electrolysis of NaCl in the fused state ………………………… is formed at cathode.
(a) sodium
(b) oxygen
(c) oxalic acid
(d) butyric acid
Answer:
(a) sodium

Question 3.
………………………… is known as chloride of lime.
(a) Calcium carbonate
(b) Sodium bicarbonate
(c) Sodium chloride
(d) Bleaching powder
Answer:
(d) Bleaching powder

Question 4.
Salt obtained from certain type of rock is called ………………………… .
(a) hard salt
(b) rock salt
(c) stone salt
(d) pure salt
Answer:
(b) rock salt

Question 5.
The ………………………… % aqueous solution of salt is called brine.
(a) 25
(b) 60
(c) 30
(d) 50
Answer:
(a) 25

Question 6.
The molecular formula for baking soda is ………………………… .
(a) Na₂CO₃
(b) NaHCO₃
(c) Na₂SO₄
(d) NaNO₃
Answer:
(b) NaHCO₃

Question 7.
Bleaching powder is also called ………………………… .
(a) Calcium oxygen chlorine
(b) Calcium oxychloride
(c) Calcium hydroxide
(d) Calcium oxalate
Answer:
(b) Calcium oxychloride

Question 8.
NaHCO₃ is also called as ………………………… .
(a) Sodium carbonate
(b) Sodium bicarbonate
(c) Sodium carbon oxide
(d) Sodium chloride
Answer:
(b) sodium bicarbonate

Question 9.
Molecular formula for Magnesium bromide is ………………………… .
(a) MgBr
(b) Mg₂Br
(c) Mg₂Br₂
(d) MgBr₂
Answer:
(d) MgBr₂

Question 10.
The molten state of NaCl is also called as ………………………… .
(a) solid state
(b) semi-solid
(c) gaseous state
(d) fused state
Answer:
(d) fused state

Question 11.
Substance used to make hard water soft is ………………………… .
(a) Na₂CO₃.10H₂O
(b) Na₂CO₃.H₂O
(c) NaCO₃.10H₂O
(d) NaCO₃.H₂O
Answer:
(a) Na₂CO₃.10H₂O

Question 12.
The fixed number of molecules of water in alum is ………………………… .
(a) 24
(b) 10
(c) 7
(d) 2
Answer:
(a) 24

Question 13.
Chlorine gas is a strong ………………………… agent.
(a) reducing
(b) oxidising
(c) neutral
(d) acidic
Answer:
(b) oxidising

Question 14.
Bleaching powder is ………………………… in colour.
(a) brownish red
(b) yellowish-white
(c) pinkish brown
(d) greenish blue
Answer:
(b) yellowish-white

Question 15.
Soap is ………………………… in nature.
(a) acidic
(b) basic
(c) neutral
(d) fuming
Answer:
(b) basic

Question 16.
Melting point of NaCl is ………………………… .
(a) 400°C
(b) 100°C
(c) 800°C
(d) 600°C
Answer:
(c) 800°C

Question 17.
Rock salt is ………………………… in colour.
(a) black
(b) white
(c) brown
(d) blue
Answer:
(c) brown

Question 18.
Strong odour in swimming pool is due to ………………………… .
(a) chlorine gas
(b) impurities
(c) calcium carbonate
(d) calcium hydroxide
Answer:
(a) chlorine gas

Question 19.
Molecular formula of sodium bicarbonate is ………………………… .
(a) NaHCO₃
(b) Na₂HCO₃
(c) Na₂HCO₂
(d) NaHCO₂
Answer:
(a) NaHCO₃

Question 20.
Soap is ………………………… in nature.
(a) radioactive
(b) natural
(c) acidic
(d) basic
Answer:
(d) basic

Question 21.
The molecular formula for Magnesium bromide is ………………………… .
(а) MgBr
(b) MgBr₂
(c) Mg₂Br₂
(d) Mg₂Br
Answer:
(b) MgBr₂

Fill in the blanks and rewrite the complete statements:

(1) 25% of NaCl is known as
(2) gas is released when bleaching powder is added to water.
(3) Washing soda is as it absorbs moisture if left exposed to air.
(4) is used to make hard water soft.
(5) Molecular formula for Alum is
(6) is used in blood test for diagnosing anaemia.
(7) High grade of and are used as raw material to manufacture bathing soap.
(8) Pickles, jams and sauce contain small quantities of and
(9) Excessive consumption of foods with added food colours leads to diseases like
(10) Melting point of Teflon is
(11) Anodizing is done by
(12) The red blood cell count increases in the disease
(13) Magnesium sulphate (MgS04.7H20) is also called
Answer:
(1) Brine
(2) Chlorine
(3) hygroscopic
(4) Na₂CO₃ (Washing soda)
(5) K₂SO₄.Al₂(SO)₃.24H₂O
(6) Blue Vitriol
(7) fats, oils
(8) lead, mercury
(9) ADHD (Attention Deficit Hyperactivity Disorder)
(10) 327°C
(11) Electrolysis
(12) Polycythemia
(13) Epsom salt
(14) Soap

State whether the following statements are true or false. Correct the false statements.
(1) Bleaching powder is used in preparation of chloroform which is used as an anaesthetic.
(2) On addition of universal indicator the colour of table salt changes to pink.
(3) Borax is Na₂B₄O₇.9H₂O.
(4) Boron -10 is used to cure bone cancer.
(5) Clinical deo contains 20 to 25% of aluminium.
(6) NaHCO₃ is sodium carbonate.
(7) Soap is acidic in nature.
(8) Baking powder is neutral in nature.
(9) POP is crystalline in nature.
(10) pH value of universal indicator is 0 – 7.
(11) Sodium chloride is formed by neutralization reaction between sodium hydroxide and calcium carbonate.
(12) Boiling point of NaCl is 800 °C.
(13) Molten state of NaCl is also called as solid state.
(14) Mineral halite is an example of Rock Salt.
(15) Sodium bicarbonate is used to reduce acidity.
(16) Bleaching powder is also called as chloride of lime.
(17) Bleaching powder is obtained by reaction of chlorine gas with slaked lime.
(18) Bleaching powder available in market is classified on the basis of colour.
(19) The hard water becomes soft on adding baking soda (NaHCO₃)
Answer:
(1) True
(2) False. On addition of universal indicator the colour of table salt changes to green.
(3) False. Borax is Na₂B₄O₇.9H₂O
(4) False. Boron – 10 is used in treatment of brain tumour.
(5) True
(6) False. NaHCO₃ is sodium bicarbonate.
(7) False. Soap is basic in nature.
(8) False. Baking powder is basic in nature.
(9) False. POP is amorphous in nature.
(10) False. pH value of universal indicator is 0 -14.
(11) False. Sodium chloride is formed by a neutralization reaction between sodium hydroxide and hydrochloric acid.
(12) False. Melting point of NaCl is 800°C.
(13) False. Molten state of NaCl is also called as fused state.
(14) True
(15) True
(16) True
(17) True
(18) False. Bleaching powder available in market is classified on the basis of percentage of chlorine present in it.
(19) False. Hard water becomes soft on adding washing soda (Na₂CO₃.10H₂O)

Name the following:

Question 1.
Important salts found in sea water.
Answer:
Magnesium chloride, Potassium chloride

Question 2.
Chemical used in preparation of breads and cakes to make them soft.
Answer:
Sodium bicarbonate

Question 3.
Gas liberated when bleaching powder is added to CO₂ gas.
Answer:
Chlorine (Cl₂) gas.

Question 4.
Salt used in refining petroleum
Answer:
Sodium carbonate (Na₂CO₃)

Question 5.
Chemical formula of bleaching powder
Answer:
CaOCl₂

Question 6.
The chemical formula of Sodium hydrogen carbonate.
Answer:
NaHCO₃

Question 7.
Nature of soap.
Answer:
Basic

Question 8.
Molecular formula for Magnesium bromide
Answer:
MgBr₂

Question 9.
Melting point of NaCl
Answer:
800 °C

Question 10.
Two examples of Rock Salt
Answer:
Mineral halite and Himalayan rock salt.

Question 11.
Uses of sodium bicarbonate
Answer:
To prepare breads, cakes and dhokla

Question 12.
Constituents of baking powder.
Answer:
Baking soda and mild acid (tartaric acid)

Question 13.
Substance used to make hard water soft.
Answer:
Washing soda i.e. Na₂CO₃.10H₂O.

Question 14.
Radioactive isotopes used in treatment of bone cancer.
Answer:
Strontium – 89, Strontium – 90, Samarium -153, Radium – 223

Question 15.
Use of Strontium 89 and strontium 90.
Answer:
Treatment of bone cancer.

Select the odd man out:

Question 1.
Sodium sulphate, Barium chloride, Magnesium sulphate, Bleaching powder.
Answer:
Bleaching powder, all others are crystalline salt with water of crystallization while bleaching powder is not.

Question 2.
Strontium – 89, Strontium – 90, Radium – 223, Iodine -123.
Answer:
Iodine -123, it is used to cure hyperthyroidism while others are used to cure bone cancer.

Question 3.
Soap, Toothpaste, Baking soda, Curd.
Answer:
Curd, it is acidic in nature while others are basic in nature.

Question 4.
Na₂CO₃.10H₂O, Na₂SO₄.10H₂O, BaCl₂.2H₂O, CaOCl₂
Answer:
CaOCl₂, it is amorphous in nature while rest are crystalline in nature.

Question 5.
Boron-10, Iodine – 131, Cobalt – 60, Iodine – 123.
Answer:
Iodine -123, it is used in hyperthyroidism while rest are used in treatment of brain tumour.

Question 6.
Na₂SO₄, K₃PO₄, MgBr₂, HCl.
Answer:
HCl, rest all are salts but HCl is an acid.

Write the correlated terms:

(1) Washing Powder : Basic :: Milk : ……………………………
(2) Na₂SO₄: Sodium sulphate :: K₃PO₄ : ……………………………
(3) CaOCl₂: Calcium Oxychloride : : NaHCO₃ : ……………………………
(4) Borax : 10H₂O : : Alum : ……………………………
(5) Sodium Sulphate : Na₂SO₄.10H₂O : : Magnesium Sulphate : ……………………………
(6) Bathing soap : High grades fats and oils :: Washing soap : ……………………………
(7) Radium – 23 : Bone cancer :: Phosphorus – 32 : ……………………………
(8) Iodine -123 : Hyperthyroidism :: Iodine -131 : ……………………………
(9) Clinical deo : 20-25% of aluminium : : Antiperspirant deo : of aluminium chlorohydrate : ……………………………
(10) Sodium carbonate : Na₂CO₃ : : Sodium bicarbonate : ……………………………
(11) Curd : Acidic : : Soap : ……………………………
(12) Calcium Carbonate : CaCO₃ : : Magnesium bromide : ……………………………
(13) Baking Soda : NaHCO₃ : : Washing Soda : ……………………………
(14) Baking Soda : Breads and Cakes : : Washing Soda : ……………………………
(15) Borax : Na₂B₄O₇.10H₂O : : Alum : ……………………………
Answer:
(1) Acidic
(2) Potassium phosphate
(3) Sodium hydrogen carbonate
(4) 24H₂O
(5) MgSO₄.7H₂O
(6) Low-grade fats and oils
(7) Polycythemia
(8) Tumour detection
(9) 15%
(10) NaHCO.
(11) Basic
(12) MgBr₂
(13) Na2CO₃.10H₂O
(14) Hard water soft
(15) K₂SO₄.Al₂(SO₄)₃.24H₂O

Match the columns:

Question 1.

Answer:
(1 – c),
(2 – d),
(3 – b),
(4 – a)

Question 2.

Answer:
(1 – d),
(2 – a),
(3 – b),
(4 -c)

Give scientific reasons:

Question 1.
Baking soda is used while making cakes.
Answer:

Question 2.
Baking soda is used to reduce acidity in the stomach.
Answer:

Question 3.
Tap water and water in swimming pool has a typical strong odour in the rainy season.
Answer:

Question 4.
Sodium carbonate is added to hard water to make it soft.
Answer:

Question 5.
Alum is used in the process of water purification.
Answer:

Question 6.
Overconsumption of artificial food colours should be avoided?
Answer:

Question 7.
Artificial colours in Rang Panchami should be used cautiously.
Answer:

Question 8.
There are various brands of bleaching powder in the market.
Answer:

Question 9.
We use anodized cooking utensils like griddles and cookers.
Answer:

Explain the following chemical reactions with the help of balanced equations :

Question 1.
Sodium hydroxide reacts with dilute Hydrochloric acid.
Answer:
When Sodium hydroxide reacts with dilute Hydrochloric acid, it forms sodium chloride and water.
This is a neutralization reaction.

Question 2.
When an electric current is passed through a saturated solution of sodium chloride (brine)
Answer:
When an electric current is passed through a saturated solution of sodium chloride (brine) it is electrolysed and hydrogen gas is released at the cathode while chlorine gas is released at the anode. Also, an important basic compound NaOH is formed in the cell.

Question 3.
Baking soda (Sodium hydrogen carbonate) reacts with dilute hydrochloric acid.
Answer:
When Sodium bicarbonate (Sodium hydrogen carbonate) reacts with dilute hydrochloric acid, it gives sodium chloride, water and carbon dioxide gas is liberated.

Question 4.
Bleaching powder is exposed to air.
Answer:
When bleaching powder is exposed to air, it undergoes slow decomposition due to the carbon dioxide in air and chlorine gas is released.

Question 5.
When dry slaked lime reacts with chlorine gas.
Answer:
When dry slaked lime reacts with chlorine gas, it gives bleaching powder.

Question 6.
Bleaching powder reacts with dilute sulphuric acid.
Answer:
Dilute sulphuric acid reacts rapidly with bleaching powder to form calcium sulphate and release chlorine gas completely.

Question 7.
Bleaching powder reacts with dilute hydrochloric acid.
Answer:
Dilute hydrochloric acid reacts rapidly with bleaching powder to form Calcium chloride and release chlorine gas completely.

Question 8.
Sodium carbonate reacts with magnesium chloride.
Answer:
When Sodium carbonate reacts with magnesium chloride, it forms insoluble magnesium carbonate and sodium chloride. This reaction is used to make hard water soft.

Question 9.
Crystalline sodium carbonate is exposed to air.
Answer:
When crystalline sodium carbonate is exposed to air it loses its water of crystallization readily and a white powder is obtained. This powder is called washing soda.

Question 10.
Sodium carbonate reacts with sulphuric acid.
Answer:
When sodium carbonate reacts with sulphuric acid it forms sodium sulphate, water and carbon dioxide gas is liberated.

Distinguish between;

Question 1.
Washing soda and Baking soda
Answer:

Question 2.
Bathing soap and Washing soap
Answer:

Answer the following:

Question 1.
Give the properties and uses of Sodium bicarbonate.
Answer:
Properties and uses of sodium bicarbonate

Question 2.
Give the properties and uses of washing soda.
Answer:
Properties and uses of washing soda :

Question 3.
Name some substances in our daily use which contain water of crystallization.
Answer:

Question 4.
Give the uses of radioactive isotopes in the measurement of thickness, density and level.
Answer:
Measurement of thickness, density and level:

Question 5.
Give the uses of radioactive isotopes in Luminescent paint and radioluminescence.
Answer:
Luminescent paint and radioluminescence:

Question 6.
Give the uses of radioactive isotopes in Field of agriculture.
Answer:
Field of agriculture:

Question 7.
Give the uses of dyes.
Answer:
Uses of dyes :

Question 8.
What are the adverse effects of dyes?
Answer:
Adverse effects dyes :

Question 9.
Give the uses of teflon.
Answer:
Uses of teflon :

Question 10.
What is ceramic? Give examples.
Answer:

Question 11.
Give the uses of ceramics.
Answer:

Question 12.
What is brine? What happens when ^th of this solution is evaporated?
Answer:

Question 13.
What is baking soda? Give its chemical name and molecular formula.
Answer:

Question 14.
Give two uses of Blue vitriol.
Answer:

Question 15.
What is radioactivity and what are radioactive substances?
Answer:

Question 16.
What can you say about the uses of radioactive isotopes?
Answer:

Question 17.
Give the uses of radioactive isotopes in Radiography.
Answer:

Question 18.
Give the uses of radioactive isotopes in ceramic articles.
Answer:

Question 19.
What is a dye?
Answer:
The coloured substance which on applying to an article, imparts that colour to the article, is called a dye

Question 20.
What is done to fix a dye on the cloth ?
Answer:

Question 21.
What is Teflon? Give its chemical name.
Answer:

Question 22.
What is powder coating? Why is it done?
Answer:

Question 23.
Give the properties of ceramics.
Answer:

Question 24.
How is bone china made? How is it different from porcelain?
Answer:

Question 25.
What compounds are used instead of clay for making advanced ceramic?
Answer:
Oxides like Alumina (Al₂O₃), Zirconia (ZrO₂) Silica (SiO₂) and some other compounds like silicon carbide (SiC), boron carbide (B₄C) are used instead of clay for making advanced ceramic.

Question 26.

What is sintering?
Answer:

Write short notes on :

Question 1.
Chernobyl disaster.
Answer:

Question 2.
Food colours.
Answer:

Question 3.
Anodizing.
Answer:

Answer the following questions:

Question 1.
What are salts? Give their source.
Answer:

Question 2.
Which are the three kinds of salts depending on their pH value? How are they formed?
Answer:
The three kinds of salts depending on their pH value are:

Neutral salts:
Salt is neutral when its pH value is 7. Such a salt is made from a strong acid and a strong base.

Acidic salts:
The pH value of a salt made from a strong acid and a weak base is less than 7 and it is acidic.

Basic salts:
The pH value of a salt made from a weak acid and strong base is more than 7 and it is basic.

Question 3.
Which is the most used salt? What is its chemical name? How is it formed?
Answer:

Question 4.
How is bleaching powder obtained?
Answer:

Question 5.
How is hard water from well converted to soft water?
Answer:

Question 6.
How is washing soda obtained from sodium carbonate?
Answer:

Question 7.
How is soap prepared? Why it does not form lather with hard water?
Answer:

Question 8.
What are the harmful effects of artificial food colours?
Answer:

Question 9.
Which is the main source of colour for preparing a natural dye?
Answer:

Question 10.
How are artificial colours harmful to us?
Answer:

Question 11.
What are the harmful effects of deodorants?
Answer:

Question 12.
How is a ceramic article made?
Answer:

Question 13.
What is porcelain? How is it made?
Answer:

Answer the following questions:

Question 1.
What are the constituents of baking powder? Where is the baking powder used?
Answer:

Question 2.
Take a piece of coloured cloth. Put some saturated solution of bleaching powder on a small part and observe what changes take place in the colour of the cloth.
Answer:
When bleaching powder is added to a piece of coloured cloth, the fabric looses its colour due to the oxidising reaction of the chlorine present in the bleaching powder.

Answer in detail:

Question 1.
Give the properties and uses of Sodium chloride.
Answer:
Properties and uses of sodium chloride:

Question 2.
Give the properties and uses of Bleaching Powder.
Answer:
Properties and uses bleaching powder:

Question 3.
Explain with neat labelled diagram the nature of radioactive radiation.

Question 4.
Give the characteristics of alpha, beta and gamma rays.
Answer:
Characteristics of alpha, beta and gamma rays are as given in the table.

Question 5.
Give the uses of radioactive isotopes in Medical science.
Answer:
Medical science:

Question 6.
What are the hazards of radioactive substances and radiation?
Answer:

Question 7.
Why are deodorant used? Give their types and content.
Answer:

Question 8.
Explain how powder coating is done.
Answer: