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Chemical Reactions And Equations_LS_17

Total questions: 68

Worksheet time: 35mins

Name
Class
Date
1.

Those reactions in which one element takes the place of another element in a compound, are known as displacement reactions.

Example: CuSO4 (aq) + Zn (s) —–>ZnSO4 + Cu

a)

displacement reaction,

b)

double displacement reaction

2.

Those reactions in which two compounds react by an exchange of ions to form two new compounds are called double displacement reactions.

Example: AgNO3 (aq) + NaCl (aq)

a)

displacement reaction,

b)

double displacement reaction

3.
AgNO3
a)
Silver Nitrate
b)
Silver (I) Nitrate
c)
Silver Nitride
d)
Silver Nitrogen Trioxide
4.

Which method is used to prepare silver chloride?

a)

Add excess solid reactant to acid

b)

Titration

c)

Precipitation

5.

Which is the most suitable method for separating the products of the reaction below:

When silver nitrate solution is added to sodium chloride solution, then a white precipitate of silver chloride is formed along with sodium nitrate solution. In this reaction, two compounds, silver nitrate and sodium chloride, react to form two new compounds, silver chloride and sodium nitrate.

NaCl (aq) + AgNO3 (aq) --> AgCl (s) + NaNO3 (aq)

a)

chromatography

b)

crystallisation

c)

distillation

d)

filtration

6.

NaCl (aq) + AgNO3 (aq) --> AgCl (s) + NaNO3 (aq).

When silver nitrate solution is added to sodium chloride solution, then a white precipitate of silver chloride is formed along with sodium nitrate solution. In this reaction, two compounds, silver nitrate and sodium chloride, react to form two new compounds, silver chloride and sodium nitrate. Which method is used to prepare silver chloride?

a)

Add excess solid reactant to acid

b)

Titration

c)

Precipitation

7.

Why are decomposition reactions called the opposite of combination reactions ? Explain with equations of these reactions. What is the first statement of the audio clip?

a)

Those reactions in which a compound splits up into two or more simpler substances are known as decomposition reactions.

b)

Example: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.

c)

They are called opposite of combination reactions because in a combination reaction, two or more substances combine to form a single substance.

d)

Example: Magnesium and oxygen combine, when heated, to form magnesium oxide.

8.

Why are decomposition reactions called the opposite of combination reactions ? Explain with equations of these reactions. What is the second statement of the audio clip?

a)

Those reactions in which a compound splits up into two or more simpler substances are known as decomposition reactions.

b)

Example: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.

c)

They are called opposite of combination reactions because in a combination reaction, two or more substances combine to form a single substance.

d)

Example: Magnesium and oxygen combine, when heated, to form magnesium oxide.

9.

Why are decomposition reactions called the opposite of combination reactions? Explain with equations of these reactions. What is the third statement of the audio clip?

a)

Those reactions in which a compound splits up into two or more simpler substances are known as decomposition reactions.

b)

Example: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.

c)

They are called opposite of combination reactions because in a combination reaction, two or more substances combine to form a single substance.

d)

Example: Magnesium and oxygen combine, when heated, to form magnesium oxide.

10.

Why are decomposition reactions called the opposite of combination reactions? Explain with equations of these reactions. What is the fourth statement of the audio clip?

a)

Those reactions in which a compound splits up into two or more simpler substances are known as decomposition reactions.

b)

Example: When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide.

c)

They are called opposite of combination reactions because in a combination reaction, two or more substances combine to form a single substance.

d)

Example: Magnesium and oxygen combine, when heated, to form magnesium oxide.

11.

Express the following facts in the form of a balanced chemical equation: "When a strip of copper metal is placed in a solution of silver nitrate, metallic silver is precipitated and a solution containing copper nitrate is formed”.

a)

Cu (s) + 2AgNO3 (aq)—–>Cu(NO3)2 (aq) + 2Ag (s)

b)

2AgNO3→2Ag+2NO2​+O2​

c)

Zn+2AgNO3→Zn(NO3​)2​+2Ag

12.

What happens when a piece of iron metal is placed in copper sulphate solution ? Name the type of reaction involved.

a)

When a piece of iron metal is placed in copper sulphate solution, then magnesium sulphate solution and copper metal are formed. This is a type of displacement reaction.

b)

When a piece of iron metal is placed in copper sulphate solution, then ferrous sulphate solution and copper metal are formed. This is a type of displacement reaction.

c)

Fe + CuSO₄ = FeSO₄ + Cu (iron displaces copper in the salt solution; the iron dissolves, turning into solution, and metallic copper of a reddish color is released).

13.

What happens when a piece of iron metal is placed in copper sulphate solution ? Write a well balanced equation for the reaction

a)

When a piece of iron metal is placed in copper sulphate solution, then magnesium sulphate solution and copper metal are formed. This is a type of displacement reaction.

b)

When a piece of iron metal is placed in copper sulphate solution, then ferrous sulphate solution and copper metal are formed. This is a type of displacement reaction.

c)

Fe + CuSO₄ = FeSO₄ + Cu (iron displaces copper in the salt solution; the iron dissolves, turning into solution, and metallic copper of a reddish color is released).

d)

2AgNO3 → 2Ag + 2NO2 + O2

e)

Pb(NO3)2 + Fe2(SO4)3 → Fe(NO3)3 + PbSO4

14.

In the reaction represented by the following equation :CuO(s) + H2(g) ————- > Cu (s) + H20(1)

name the substance oxidised

a)

H2

b)

CuO

c)

CuO

d)

H2S

15.

In the reaction represented by the following equation :

CuO(s) + H2(g) ————- > Cu (s) + H20(1)

name the substance reduced

a)

H2

b)

CuO

c)

Cu

d)

H2

16.

In the reaction represented by the following equation :

CuO(s) + H2(g) ————- > Cu (s) + H20(1)

name the oxidising agent

a)

H2

b)

CuO

c)

Cu

d)

H2

17.

In the reaction represented by the following equation :

CuO(s) + H2(g) ————- > Cu (s) + H20(1)

name the reducing agent

a)

H2

b)

CuO

c)

Cu

d)

H2

18.

What happens when silver nitrate solution is added to sodium chloride solution ?

a)

When silver nitrate solution is added to sodium chloride solution, then a white precipitate of silver chloride is formed along with sodium nitrate solution.

b)

AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq). This is a precipitation reaction: AgCl is the formed precipitate. ; Colorless to slightly yellow gas with a pungent, irritating odor.

c)

Ag+ + Cl- → AgCl (s)

19.

What happens when silver nitrate solution is added to sodium chloride solution ?(a) Write the equation for the reaction which takes place.

a)

AgNO3(aq) + NaCl (aq)

b)

AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq). This is a precipitation reaction: AgCl is the formed precipitate. ; Colorless to slightly yellow gas with a pungent, irritating odor.

c)

Ag+ + Cl- → AgCl (s)

20.

What happens when silver nitrate solution is added to sodium chloride solution? Name the type of reaction involved

a)

Single Displacement Reaction

b)

Double Displacement Reaction

c)

Combination Reaction

d)

Precipitation Reaction.

e)

Decomposition Reaction.

21.

Decomposition Reaction. What is the first statement of the video clip?

a)

Decomposition Reactions:

the reaction in which a single compound

breaks up into two or more simple substances is known as

reactions

b)

The decomposition reaction generally takes place when energy in some form such as heat, electricity or light is

supplied to the reactants

c)

CaCO3(s)+heat (when heated) → CaO(s) + CO2(g)

d)

decomposition of a substance by heating is thermal decomposition

e)

Electrolysis: the decomposition of a substance by passing electric current through it is

known as electrolysis

22.

Decomposition Reaction. What is the second statement of the video clip?

a)

2 NaCl(l) (electrolysis) ---> 2 Na(l) + Cl2(g)

Sodium chloride on passing electric current gives sodium 2na and chlorine cl2

b)

The decomposition reaction generally takes place when energy in some form such as heat, electricity or light is

supplied to the reactants

c)

CaCO3(s)+heat (when heated) → CaO(s) + CO2(g)

d)

decomposition of a substance by heating is thermal decomposition

e)

Electrolysis: the decomposition of a substance by passing electric current through it is

known as electrolysis

23.

Decomposition Reaction. What is the third statement of the video clip?

a)

2 NaCl(l) (electrolysis) ---> 2 Na(l) + Cl2(g)

Sodium chloride on passing electric current gives sodium 2na and chlorine cl2

b)

Photolysis: the decomposition of a compound with light is called photolysis

c)

CaCO3(s)+heat (when heated) → CaO(s) + CO2(g)

d)

decomposition of a substance by heating is thermal decomposition

e)

Electrolysis: the decomposition of a substance by passing electric current through it is

known as electrolysis

24.

Decomposition Reaction. What is the fourth statement of the video clip?

a)

2 NaCl(l) (electrolysis) ---> 2 Na(l) + Cl2(g)

Sodium chloride on passing electric current gives sodium 2na and chlorine cl2

b)

Photolysis: the decomposition of a compound with light is called photolysis

c)

study of decomposition of silver chloride: take about 2 grams of silver chloride in

a china dish

d)

decomposition of a substance by heating is thermal decomposition

e)

Electrolysis: the decomposition of a substance by passing electric current through it is

known as electrolysis

25.

Decomposition Reaction. What is the fifth statement of the video clip?

a)

2 NaCl(l) (electrolysis) ---> 2 Na(l) + Cl2(g)

Sodium chloride on passing electric current gives sodium 2na and chlorine cl2

b)

Photolysis: the decomposition of a compound with light is called photolysis

c)

study of decomposition of silver chloride: take about 2 grams of silver chloride in

a china dish

d)

place this china dish in the sunlight for sometime

e)

Electrolysis: the decomposition of a substance by passing electric current through it is

known as electrolysis

26.

Decomposition Reaction. What is the sixth statement of the video clip?

a)

2 NaCl(l) (electrolysis) ---> 2 Na(l) + Cl2(g)

Sodium chloride on passing electric current gives sodium 2na and chlorine cl2

b)

Photolysis: the decomposition of a compound with light is called photolysis

c)

study of decomposition of silver chloride: take about 2 grams of silver chloride in

a china dish

d)

place this china dish in the sunlight for sometime

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

27.

Decomposition Reaction. What is the seventh statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

Photolysis: the decomposition of a compound with light is called photolysis

c)

study of decomposition of silver chloride: take about 2 grams of silver chloride in

a china dish

d)

place this china dish in the sunlight for sometime

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

28.

Decomposition Reaction. What is the eighth statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

study of decomposition of silver chloride: take about 2 grams of silver chloride in

a china dish

d)

place this china dish in the sunlight for sometime

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

29.

Decomposition Reaction. What is the ninth statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

2AgBr (when exposed to light) ----> 2Ag +Br2

d)

place this china dish in the sunlight for sometime

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

30.

Decomposition Reaction. What is the tenth statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

2AgBr (when exposed to light) ----> 2Ag +Br2

d)

the above reactions are used in black and white photography

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

31.

Decomposition Reaction. What is the eleventh statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

2AgBr (when exposed to light) ----> 2Ag +Br2

d)

the above reactions are used in black and white photography

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

32.

Decomposition Reaction. What is the Twelfth statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

2AgBr (when exposed to light) ----> 2Ag +Br2

d)

the above reactions are used in black and white photography

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

33.

Decomposition Reaction. What is the Thirteenth statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

2AgBr (when exposed to light) ----> 2Ag +Br2

d)

the above reactions are used in black and white photography

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

34.

Decomposition Reaction. What is the Fourteenth statement of the video clip?

a)

2AgCl (on exposure to sunlight) ---- 2Ag +Cl2

b)

silver bromide undergoes decomposition when exposed to light

c)

2AgBr (when exposed to light) ----> 2Ag +Br2

d)

the above reactions are used in black and white photography

e)

it is observed that the white silver chloride turns gray on exposure to sunlight

35.

What is corrosion?

a)

The release of oxygen

b)

Breakdown of a metal

36.

Iron rust in the presence of:

a)

Oxygen

b)

Vacuum

c)

Moisture

d)

Moisture and Oxygen

37.

Is this an example of corrosion?

a)

Yes

b)

No

38.

Deterioration of metal due to the corrosive environment

a)

Erosion

b)

Corrosion

c)

Both A & B

d)

None of these

39.

Corrosion of Metals involves

a)

Physical reactions

b)

chemical reactions

c)

Both

d)

None

40.

Define metal corrosion.

a)

Deterioration of metal by chemical or electrochemical attack that can occur internally & externally.

b)

Changes smooth surface.

c)

weakens interior, damages and/or loosens adjacent parts.

d)

All are correct.

41.

Explain the corrosion process.

a)

Metal that is oxidized (loss of electron) suffers anodic change.

b)

Corrosive agent reduced (gain of electron) undergoes cathodic change.

c)

Both are correct.

42.

Whats is corrosion?


Please select CORRECT answer.

a)

Elecctrochemical process in which metals are eaten up gradually by the action of air, moisture or a chemical (such as an acid) on their surface.

b)

The process of eroding or being eroded by wind, water, or other natural agents

43.

Which metals rusts?

a)

Copper

b)

manganese

c)

iron

d)

potassium

44.

What environmental element assists rusting?

a)

nitrogen

b)

oxygen

c)

carbon

d)

hydrogen

45.

What conditions are required for rusting?

a)

dry cold conditions

b)

dry hot conditions

c)

hot damp conditions

46.

What is the chemical name given to Rust ?

a)

Iron dioxide

b)

Iron oxide

c)

Steel oxide

d)

Carbon dioxide

47.

What prevents Rusting

a)

Painting , Oiling , Galvinising

b)

Washing with water

48.

What is the chemical name given to Rust ?

a)

hydrated iron(I) oxide

b)

Iron (I) oxide

c)

iron(II) hydroxide

d)

hydrated iron(III) oxide

49.

Which of the following does not prevent rusting of iron?

a)

Painting , Oiling , Galvinising

b)

Attach to a piece of copper

c)

connect to a piece of magnesium with wire

d)

cover entirely with copper

50.

In which tube will the nail go rusty?

a)

The nail in tube A will go rusty.

b)

The nail in tube B will go rusty.

c)

The nail in tube C will go rusty.

51.

A rusting bicycle

a)

physical change

b)

chemical change

52.

Rusting is an example of

a)

oxidation

b)

reduction

53.

What two things cause Iron to Rust ?

a)

Air and Oxygen

b)

Water and Carbon dioxide

c)

Oxygen and Water

d)

Carbon dioxide and Air

54.

A layer of reddish brown on surface of a metal is called...

a)

red paint

b)

red dirt

c)

rust

d)

brown rust

55.

Choose an object that can rust.

a)

Iron spoon

b)

Straw

c)

String

d)

Aluminium pot

56.

Which of the following groups consist of rusty objects?

a)

Nail, key, board and marble

b)

Nail, marble. needle and screw

c)

Nail, key, needle and screw

d)

Marble. rubber band and clothes

57.

Two factors that cause rusting are the presence of ......... and ...........

a)

oxygen

b)

water

c)

hydrogen

d)

carbon dioxide

58.

Which of the following can rust?

a)
b)
c)
d)
59.

Choose the correct characteristics of rusty objects.

a)

Strong

b)

Stiff

c)

Rough surface

d)

Brittle

e)

Looks new

60.

Only objects that are made from iron and steel will rust.

a)

TRUE

b)

FALSE

61.

Why wooden bench do not rust?

a)

because it is made of plastic.

b)

because it is made of wood.

c)

because it is made of iron.

62.
a)

Can rust

b)

Does not rust

63.

9.An experiment has been carried out by a group of pupils. The results of the

experiment are recorded in Table 2.

What can be concluded from this experiment?

a)

Nail X did not rust because exposed to the air and water.

b)

Nail Y rusts because exposed to the air and water

c)

Nail X did not rust because exposed to the oil layer.

d)

Nail Z did not rust because exposed to water.

64.

6.Table shows the results of an investigation

by a group of Year 5 Zircon pupils.

What is the conclusion that can be made

from the results of this investigation?

a)

Rusty objects are made of iron.

b)

Non-rusty objects are made of iron.

c)

Rusty objects are brownish colour.

d)

Rusty objects are made of plants.

65.

Which nail rusts first?

a)

Nail in test tube A

b)

Nail in test tube C

c)

Nail in test tube E

d)

Nail in test tube F

66.

How do you prevent this food can from rusting?

a)

painting

b)

apply oil or grease

c)

coating with plastic

d)

plating with non rusty metal

67.

An investigation was carried out by year 5 pupils to study the factors that cause rusting. What is the function of anhydrous calcium chloride in this investigation?

a)

To protect the iron nail

b)

To increase the rate of the rusting process

c)

To absorb the moisture in the air

d)

To supply oxygen in the test tube

68.

Which of the following methods can prevent rusting?

a)

applying grease on objects made from iron

b)

painting steel objects

c)

cover steel and iron objects with a damp cloth

d)

cover steel objects with non-rusty material