10th Class Chemistry Chapter 7 Short Questions with Answers Solved

Question: 1

Define blister copper

Answer: 1

1-75

The molten matte is shifted from converter to sand moulds and is allowed to cool . The dissolved gasses escape out forming blister on the surface of the slod copper . It is called blister copper . It is 98% pure copper

Question: 2

Define anode mud

Answer: 2

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In the process of refining of metal the impurities like gold and silver settle down at the bottom of electrolyte tank called anode mud

Question: 3

Define principle of froth flotation

Answer: 3

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Froth flotation is based on the wetting characteristics of the ore and gangue particles with oil and water respectively

Question: 4

Define matte

Answer: 4

4-75

Cuprous sulphide and ferrous sulphide form a mixture Cu₂S . FeS called matte

Question: 5

Give names of raw material used in Urea manufacturing ?

Answer: 5

5-75

1: Ammonia (NH₃)

2: Carbon dioxide (CO₂)

Question: 6

Name two ores of copper

Answer: 6

6-75

Copper glance Cu₂S

Chalcopyrite CuFeS₂

Question: 7

Give names of raw material and used in solvay's process

Answer: 7

7-75

The raw material are

1: Brine (NaCl)

2: Limestone (CaCO₃)

3: Ammonia gas (NH₃)

Question: 8

Define smelting .

Answer: 8

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It is further heating of roasted ore with sand flux and coke in the presence of excess of air

Question: 9

Define gangue

Answer: 9

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The earthly and other impurities associated with minerals are called gangue

Question: 10

Define principle of solvay's process

Answer: 10

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Principle of solvay's process lies in low solubility of sodium bicarbonate at low temperature i-e 15℃ when CO₂is passed through ab ammonical solution of NaCl called brine only NaHCO₃precipitate

Question: 11

ICI stand for what ?

Answer: 11

11-75

Imperial chemical industries

Question: 12

Give two advantages of solvay's process

Answer: 12

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1: Carbon dioxide and ammonia are recovered and reused

2: Sodium carbonate of very high purity is obtained

Question: 13

Name fraction of petroleum

Answer: 13

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1: Petroleum gas

2: Petroleum ether

3: Gasoline

4: Kerosene oil

5: Diesel oil

6: Fuel oil

Question: 14

Give the reaction of formation of ammonia in the process ?

Answer: 14

14-75

Ammonia is recovered in this tower from ammonium chloride solution produced in the carbonated tower and calcium hydroxide formed in lime kiln

Question: 15

Define petroleum

Answer: 15

15-75

Petroleum means rock oil . It is a complex mixture of several gaseous , liquid and solid hydrocarbons having water , salts and earth particles with it

Question: 16

Name preventive methods of water borne diseases.

Answer: 16

16-75

Provision of safe water. Disposal of sewage Control of toxic chemicals.

Question: 17

Define refining

Answer: 17

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Refining process is the separation of crude oil mixture into various useful fractions

Question: 18

In which field analytical chemist work ?

Answer: 18

18-75

Analytical chemists work in almost all fields of industry . They identify the materials , measures their quantities and control the quality of the products . They evaluate the efficiency and devise techniques to enhance the production

Question: 19

Fraction of residual oil

Answer: 19

19-75

Lubricants

Asphalt

Paraffin wax

Petroleum coke

Question: 20

How NaHCO_3(S) is converted intoNa₂CO₃?

Answer: 20

20-75

Sodium bicarbonate is heated to get sodium carbonate

NaHCO_3(S) → Na₂CO_3(s) + CO_2(g) +H₂O_(g)

Question: 21

How CO₂prepared in the Solvay's process ?

Answer: 21

21-75

CO2 is prepared by heating limestone in a lime kiln . Then it is carried to carbonating tower

Question: 22

Give use of kerosene oil

Answer: 22

22-75

Used as domestic fuel , a special grade of it is used as jet fuel

Question: 23

Give three effects of water pollution?

Answer: 23

23-75

a. It is damaging aquatic life, thus breaking a link of food chain. b. It reduces the aesthetic quality of lakes and rivers. 3. It is unfit for cleaning or washing purpose.

Question: 24

What role play technology in the production of common chemicals .

Answer: 24

24-75

Technology is considered a consequences of science and engineering . Common chemicals such as acids alkalies , salts ,soaps , detergents etc are being produced on commercial scale by chemists or chemical engineers since centuries . Technology began to influence human efforts to produce common chemicals since people began using different tools and machineries . Now it is because of use of technology that needs of people are being fulfilled . Use of technology has increased the production with improved quality of products

Question: 25

Describe preparation of ammonia by (Haber's Process) ?

Answer: 25

25-75

Ammonia is prepared by the Haber's process . One volume of nitrogen (from air) and three volumes of hydrogen (obtained by passing methane and steam over heated nickel ) is passed over iron catalyst at 450℃ and 200 atm pressure

Question: 26

Why use of detergents is increasing day by day?

Answer: 26

26-75

Use of detergents is increasing day by day for cleaning purposes in houses and industries. It is because, detergents have strong cleaning action than that of soap even in hard water.

Question: 27

In which field physical chemist work ?

Answer: 27

27-75

Physical chemists have working opportunities in energy transformation industries . They develop new an better energy sources . They explore renewable energy fields

Question: 28

Why a small amount ok coke is required in the smelting process ?How is slag formed during smelting

Answer: 28

28-75

It is highly exothermic process , therefore , a small amount ok coke is required in the process . In the process , first ferrous sulphide oxidize to form ferrous oxide which reacts with sand to form iron silicate slag (FeSiO₃) . It being lighter rise to the top and is removed from the upper hole

Question: 29

Name the various metallurgical operations

Answer: 29

29-75

1: Concentration of the ore

2: Extraction of the metal and

3: Refining of the metal

Question: 30

Why are pesticides used?

Answer: 30

30-75

Pesticides are used either directly to kill or control the growth of pests. Pests may be weeds,herbe insects, fungi, viruses, etc.They all damage crops and transmit diseases both to human beings and animals.

Question: 31

Describe principle of fractional distillation

Answer: 31

31-75

The principle of fractional distillation is based upon a separation of substances depending upon the boiling point

Question: 32

How is ammonia prepared for the synthesis of urea ?

Answer: 32

32-75

Ammonia is prepared by the Haber's process . One volume of nitrogen (from air ) and three volumes of hydrogen (obtained by passing methane and steam over heated nickel catalyst ) is passed over iron catalyst at 450° C AND 200 atm pressure

Question: 33

Tell two reasons of importance of water.

Answer: 33

33-75

firstly. It is essential and major component of each and every living cell secondly. It provides an environment for animals and plants that live to water.

Question: 34

State urea formation

Answer: 34

34-75

When ammonium carbonate is evaporated with the help of steam . It dehydrates to form urea

Question: 35

How petroleum is extracted ?

Answer: 35

35-75

Petroleum is extracted by drilling holes into earth's crust where the oil is formed

Question: 36

Give use of petroleum ether

Answer: 36

36-75

Used as laboratory solvent and for dry cleaning purpose

Question: 37

Define water borne diseases.

Answer: 37

37-75

Diseases that spread because of drinking polluted water or eating food prepared with polluted water are called water borne infectious diseases.

Question: 38

Give the advantages of Solvay's process

Answer: 38

38-75

1: It is a cheap process as raw materials are available at very low prices

2: Carbon dioxide and ammonia are recovered and reused

3: Process is pollution free, because the only waste is calcium chloride solution

4: Sodium carbonate of very high purity is obtained

5: Consumption of fuel is very less since no solution is to be evaporated

Question: 39

Define concentration process used in metallurgy of copper

Answer: 39

39-75

The process of removal of gangue from the ore is technically known as concentration and the purified ore is called the concentrate . Concentration of the crushed ore is carried out by the following methods

1: Gravity separation

2: Froth flotation process

3: Electromagnetic separation

Question: 40

What is capillary action?

Answer: 40

40-75

Capillary action is the process by which water rises up from the roots of plants to leaves.This process is vital for the survival of the land plants.

Question: 41

What are the advantages of solvay's process ?

Answer: 41

41-75

1: It is a cheap process as raw material are available at very low prices

2: Carbon dioxide and ammonia are recovered and reused

3: Process is pollution free , because the only waste is calcium chloride solution

4: Sodium carbonate of very high purity is obtained

Question: 42

Define petroleum

Answer: 42

42-75

Petroleum is a natural product found under the Earth's crust trapped in rocks . Petroleum means rock oil . It is a complex mixture of several gaseous , liquid and solid hydrocarbons having water salts and earth particles with it . It is lighter than water and is insoluble in it

Question: 43

Give use of fuel oil

Answer: 43

43-75

It is used in ships and industries to heat boilers and furnaces

Question: 44

What is difference between slag and matte ?

Answer: 44

44-75

Slag mixture of metals silicate and phosphates while cuprous while cuprous sulphide and ferrous sulphide form a mixture (Cu2S.FeS) .This molten mixture is called matte

Question: 45

How pesticides cause water pollution?

Answer: 45

45-75

Intensive cultivation of crops causes these chemicals from fertilizers to seep into the groundwater commonly called leaching process. The high nitrate contents in groundwater in mainly because of irrigation run off from agricultural field.

Question: 46

What role is played by pine oil in the forth floatation process ?

Answer: 46

46-75

Oil coated or partials begins lighter come to the surface in the form of forth that can be skimmed

Question: 47

What is the percentage of nitrogen in urea ?

Answer: 47

47-75

It consists of 46.6% nitrogen

Question: 48

Why is lime added in the smelting process ?

Answer: 48

48-75

Lime is used to separate the gangue in the form of slag

Question: 49

Mention the chemical reactions for the formation of metallic copper in the bessemerization process

Answer: 49

49-75

2Cu₂S_(I) + 3O₂ → 2Cu₂O_(I) + 2SO_2(g)↑

2Cu₂O_(I) + Cu₂S_(I)→ 6Cu_(l) + SO_2(g)↑

Question: 50

How are slag and matte removed from the blast furnace ?

Answer: 50

50-75

Cuprous sulphide also oxidize to form cuprous oxide which reacts with unreacted ferrous sulphide to form ferrous oxide and cuprous sulphide . In this way , cuprous sulphide and ferrous sulphide form a mixture (Cu₂S.FeS) . This molten mixture is called matte . It is withdrawn from the lower hole . It contains about 45% of copper . Slag FeSiO₃is light water and remove from upper hole

Question: 51

What are the names of types of the hard water.

Answer: 51

51-75

There are two types of water hardness. Temporary hardness Permanent hardness.

Question: 52

What happen when ammonical brine id carbonated ?

Answer: 52

52-75

Ammonical brine is fed into carbonating tower and carbon dioxide is passed through it . Following reactions takes place in the carbonating tower

Question: 53

Explain process of electro refining ?

Answer: 53

53-75

Refining the impure metal by electrolysis is the most widely used process of refining metals . Example , electrolytic refining of copper is carried out in an electrolytic tank having copper sulphate solution in it . . Two electrodes : one of impure copper metal that acts as anode and the other of pure copper metal that acts as cathode are suspended in the electrolytic solution

On passing the electric current through the solution, anode (impure coper ) dissolves to provide Cu²⁺ ions to the solution . These CU²⁺ions are discharged by gaining of electrons from the cathode . Thereby copper atoms deposit on the cathode , making it thick block of pure copper metal . The impurities like gold and silver settle down as anode mud

Question: 54

What happens when ammonium carbonate is heated with steam ?

Answer: 54

54-75

When ammonium carbonate is evaporated with the help of steam , it dehydrates to form urea

Question: 55

Which element required by plants ?

Answer: 55

55-75

Crops needs phosphors and nitrogen to grow well . Although there is 78% nitrogen in air yet it can't be assimilated directly by plants . Therefore fertilizer are used to provide these essential elements to soil and ultimately plants

Question: 56

What temporary hardness use.

Answer: 56

56-75

Temporary hardness by boiling , by clark's method

Question: 57

In which field organic chemist work ?

Answer: 57

57-75

Organic chemists have career in pharmaceutical , petroleum , petrochemicals , cosmetics , polymer and plastic industries

Question: 58

Tell some use of water in our daily life?

Answer: 58

58-75

Uses of water in our daily life are for drinking, cooking, washing purposes etc.

Question: 59

What is the principle of functional distillation ?

Answer: 59

59-75

Refining is the process of separation of crude oil mixture into various useful products (functions ) . It is carried out by a process called fractional distillation . The principle of fractional distillation is based upon separation depending upon their boiling points

Question: 60

What permanent hardness removal.

Answer: 60

60-75

By using washing soda Using sodium zeolite.

Question: 61

In which field inorganic chemist work ?

Answer: 61

61-75

Inorganic chemist work in metallurgical industries , manufacturing industries like textile , cement sugar and chemicals , manufacturing plants like fertilizer , acids and caustic soda

Question: 62

If you add a lump of cesium to water in a glass tough,what will happen?

Answer: 62

62-75

Trhe reaction is so vigorous that the tough will shelter into small pieces.

Question: 63

What is residual oil and given the names of its fractions ?

Answer: 63

63-75

The residual oil , which does not vapourize is collected and heat above 400° C for further fractional distillation . The four fractions of residual oil are lubricants ,paraffin wax , asphalt and petroleum coke

Question: 64

What is function of fertilizers?

Answer: 64

64-75

Fertilizers are used to make up the deficiency of nitrogen, phosphorus, etc, of the soil because of intensive cultivation of crops in the recent years.

Question: 65

Differentiate between soft and hard water.

Answer: 65

65-75

Soft water: Soft water is that which produces good lather with soap

Question: 66

How is the roasting carried out ?

Answer: 66

66-75

It is a process of heating the concentrated ore to a high temperature in excess of air .

Example : copper pyrite (CuFeS₂) is strongly heated in excess of air to covert it into a mixture of cuprous sulphide and ferrous sulphide (Cu2S+FeS) .Whle impurities react with oxygen to form 2 volatile oxides

Question: 67

Write down the the names of four fractions obtained by the fractional distillation of residual oil ?

Answer: 67

67-75

1: Lubricant

2: Paraffin wax

3: Asphalt

4: Petroleum

Question: 68

What are the effects of temporary hardness in water?

Answer: 68

68-75

1. Hard water consumes large amount of soap in washing purposes. 2. Drinking hard water causes stomach disorders. 3.Hard water is unfit for use in steam engines. boilers and turbines because insoluble calcium and magnesium salts deposit inside.They are called scales. they are bad conductors of heat and hence more fuel is used insoluble calcium and magnesium sulphates not only reduce the efficiency of the engine but also cause the boiler toburst.

Question: 69

Describe the difference between diesel oil and fuel oil

Answer: 69

69-75

Diesel oil : Fuel for buses , trucks railway engines , tube well engineers , well engines and other heavy vehicles

Question: 70

Which bacteria causes the cholera?

Answer: 70

70-75

Cholera is an acute infection caused by the bacteria "Vibrio cholera"., which may be found in water contaminated by human faces, Cholera causes severs diarrhea and can be fatal.

Question: 71

Define gravity separation method

Answer: 71

71-75

Gravity separation:gravity separation is based on the differences of metallic ore and the gangue particles

Question: 72

Difference between biodegradable and non -biodegradable substances?

Answer: 72

72-75

Biodegradable: the material which are decomposed by micro organism like bacteria and fungi Example: Dead plants and animals.

Question: 73

Give a use of kerosene oil

Answer: 73

73-75

Used a domestic fuel , a special grade of it is used as jet fuel

Question: 74

What is hepatitis?

Answer: 74

74-75

It is liver inflammation commonly caused by one of five viruses called hepatitis A,BC,C, and E. Hepatitis A and E can be transmitted by contaminated water.

Question: 75

Which petroleum fraction is used in dry cleaning ?

Answer: 75

75-75

Petroleum ether and gasoline or petrol is used in dry cleaning

Chemistry Chapters

10th Class Chapter 7 Chemistry Short Questions

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