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redox reactions

Total questions: 156

Worksheet time: 3hrs 59mins

Name
Class
Date
1.
What element is being Oxidized?
a)
N
b)
H
c)
O
d)
S
2.
Is calcium oxidized or reduced in the following reaction? 
2 CaO--> 2 Ca + O2
a)
Oxidized
b)
Reduced
3.
Which of the following half reactions correctly represents a reduction half reaction?
a)
Fe →Fe2+ + 2e-
b)
Pb4+ + 2e- →Pb2+
c)
2O-2 →O2 + 4e-
d)
Fe + 3e- →Fe3+
4.

What is the oxidation number of chlorine in HClO?

a)

0

b)

-1

c)

+1

d)

+5

5.

Reduction is the ___________ of electrons.

a)

loss

b)

gain

c)

sharing

d)

transfer

6.

What is the oxidation number of iodine in KIO3?

a)

0

b)

-1

c)

+5

d)

+1

7.

Determine the oxidation number of chromate in CrO42-.

a)

+6

b)

0

c)

+2

d)

+3

8.

Which of the following represents oxidation?

a)

C → CH4

b)

Fe3+ → Fe2+

c)

Cl2 → 2Cl-

d)

Zn → ZnO

9.

In the reaction Zn + 2HCl --> ZnCl2 + H2

which element, if any, is oxidized?

a)

Zinc

b)

Hydrogen

c)

Chlorine

d)

None

10.
Which statement is true:
Mg → Mg2+ + 2e–
a)
Mg gains 2 electrons
b)
Mg2+ loses 2 electrons
c)
Mg loses 1 electron
d)
Mg loses 2 electrons
11.
Which of the following half reactions correctly represents a reduction half reaction?
a)
Fe →Fe2+ + 2e-
b)
Pb4+ + 2e- →Pb2+
c)
2O-2 →O2 + 4e-
d)
Fe + 3e- →Fe3+
12.
What is oxidation number of H in CaH2?
a)
+1
b)
-1
c)
0
d)
+2
13.
What element always has an oxidation number of -1?
a)
Hydrogen
b)
Fluorine
c)
Chlorine
d)
Iodine
14.

What is the oxidation number of C in SrCO3?

a)

-4

b)

+2

c)

-6

d)

+4

15.

Substance that oxidizes another substance by accepting its electrons.

a)

reducing agent

b)

oxidation number

c)

disproportionation

d)

oxidizing agent

16.

Which equation represents a redox reaction?

a)

NaOH + HNO3 → NaNO3 +H2O

b)

2AgNO3 + Zn → Zn(NO3)2 + 2Ag

c)

2NaCl + Pb(NO3)2 → PbCl2 + 2NaNO3

d)

CaCO3 + 2HCl → CaCl2 + H2O + CO2

17.

What is the oxidation number of X in XO4-?

a)

+4

b)

+5

c)

+7

d)

+8

18.

The following chemical equation represents the extraction of silicon from quartz using coke.

SiO2 + C → Si + CO2

What is the change in oxidation number of silicon?

a)

+2 to 0

b)

+4 to 0

c)

0 to +2

d)

0 to +4

19.
Is calcium oxidized or reduced in the following reaction? 
2 CaO--> 2 Ca + O2
a)
Oxidized
b)
Reduced
20.
Oxygen always has an oxidation number of...
a)
-1
b)
1
c)
2
d)
-2
21.
Is calcium oxidized or reduced in the following reaction? 
2CaO--> 2Ca + O2
a)
Oxidized
b)
Reduced
22.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
23.
     In the reaction Zn + H2O --> ZnO2 + H2
 which element, if any, is oxidized? 
a)
Zinc
b)
Hydrogen
c)
Oxygen
d)
None
24.
If in a reaction, copper is reduced; its number of electrons has:
a)
Increased
b)
Decreased
c)
Remained Constant
d)
Varies Randomly
25.
If an atom loses electrons during a chemical reaction, the atom was:
a)
Oxidized
b)
Reduced
c)
Neutralized
d)
Precipitated
26.

A redox reaction is NOT:

a)

all reactions

b)

a combustion reaction

c)

a reduction-oxidation reaction

d)

a reaction in which electrons are transferred from one atom to another

27.

Combustion and single-replacement reactions are __________ redox reactions.

a)

always

b)

never

c)

sometimes

d)

mostly

28.

Defined as the loss of electrons.

a)

oxidation

b)

reduction

c)

redox

d)

OIL RIG

29.

These keep track of the movement of electrons.

a)

(+) and (-) signs

b)

oxidation numbers

c)

coefficients

d)

subscripts

30.

Combustion and single-replacement reactions are __________ redox reactions.

a)

always

b)

never

c)

sometimes

d)

mostly

31.

Cl2 + 2e- --> 2Cl - is an example of:

a)

a chemical reaction

b)

redox

c)

oxidation

d)

reduction

32.

Defined as the gain of electrons.

a)

oxidation

b)

redox

c)

reduction

d)

LEO GER

33.

What is the oxidation number of C in SrCO3?

a)

-4

b)

+2

c)

-6

d)

+4

34.

What is the oxidation number of Cr in Cr2O72- ?

a)

+14

b)

+6

c)

-6

d)

-14

35.

Substance that oxidizes another substance by accepting its electrons.

a)

reducing agent

b)

oxidation number

c)

combustion

d)

oxidizing agent

36.

Substance that reduces another substance by losing electrons.

a)

reducing agent

b)

half-reaction

c)

electronegative atom

d)

oxidizing agent

37.

What is a half-reaction of this equation, Na + Cl --> NaCl ?

a)

Cl + e- --> Cl-

b)

Cl - e- --> Cl-

c)

Na --> Na + e-

d)

Na° + Cl°--> Na+1Cl-1

38.

What is the reducing agent here: N2 + 3H2 --> 2NH3

a)

N2

b)

H2

c)

NH3

d)

2NH3

39.
What is the oxidation number of N in NO2-1?
a)
-3
b)
+4
c)
-2
d)
+3
40.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
41.

State the reducing agent in this reaction.

Cu + 4HNO3 -> Cu(NO3)2 + 2H2O + 2NO2

a)

Cu

b)

HNO3

c)

Cu(NO3)2

d)

NO2

42.

Check all the equations whereby the underlined substances has been oxidized.

a)

carbon dioxide + carbon -> carbon monoxide

b)

iron (II) oxide + aluminium -> aluminium oxide + iron

c)

copper (II) oxide + ammonia -> copper + nitrogen + water

d)

hydrogen + oxygen -> water

43.

In the reaction, Fe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)

a)

carbon monoxide is reduced

b)

carbon monoxide is the oxidising agent

c)

iron(III) oxide is oxidised

d)

iron(III) oxide is the oxidising agent

44.
Which of the following half reactions correctly represents a reduction half reaction?
a)
Fe →Fe2+ + 2e-
b)
Pb4+ + 2e- →Pb2+
c)
2O-2 →O2 + 4e-
d)
Fe + 3e- →Fe3+
45.
What type of reaction is the following? 
Zn(s) + 2Cu(NO3)2(aq) ---> 2Cu(s) + Zn(NO3)2(aq)
a)
double displacement
b)
single displacement
c)
precipitation
d)
neutralization
46.

H2O2--> H2O +O2 is an example of

a)

displacement reaction

b)

combination reaction

c)

decomposition reaction

d)

disproportionation reaction

47.
2Pb(NO3)2   -->   2PbO +  4NO2  +  O2
a)
Synthesis
b)
Decomposition
c)
Single Displacement
d)
Combustion
48.
Name the following ionic compound: Cs2S
a)
cesium sulfide
b)
cesium sulfate
c)
cesium (II) sulfate
d)
cesium (II) sulfide
49.
What  will be the result of the following: 
Br2 + NaF ->
a)
bromine will replace Na
b)
Na will replace Br
c)
Br will replace F
d)
no reaction will occur
50.

a compound having +2 oxidation state of O is

a)

H2O

b)

H2O2

c)

OF2

d)

O2F2

51.

Cl2 + 2e- --> 2Cl - is an example of:

a)

a chemical reaction

b)

redox

c)

oxidation

d)

reduction

52.

What is the oxidation number of C in SrCO3?

a)

-4

b)

+2

c)

-6

d)

+4

53.

In the reaction

2Ca(s) + O2(g) --> 2CaO(s), calcium is __________

a)

Reduced

b)

Synthesized

c)

Oxidized

d)

None of the above

54.

What substance is oxidized in the following reaction?

4Fe + 3O2 --> 2Fe2O3

a)

Iron

b)

Fluorine

c)

Oxygen

55.
If an atom loses electrons during a chemical reaction, the atom was:
a)
Oxidized
b)
Reduced
c)
Neutralized
d)
Precipitated
56.

A redox reaction is NOT:

a)

all reactions

b)

a combustion reaction

c)

a reduction-oxidation reaction

d)

a reaction in which electrons are transferred from one atom to another

57.

Number of moles of sugar in 547.2 gram are:


(Mol. mass of sugar = 342)

a)

1.6

b)

2.2

c)

342

d)

548

58.

The mass of 100 molecules of sucrose (C12H22O11) is_________.

a)

100 g

b)

342 g

c)

3.88 × 10–20 g

d)

5.68 × 10–20 g

59.

How many moles of methane are required to produce 22g of CO2(g) after combustion ?

a)

2 Moles

b)

1 Moles

c)

0.5 Moles

d)

0.05 Moles

60.

A solution is 25% water, 25% ethanol and 50% acetic acid by mass. The mole fraction of water is:

a)

0.6

b)

0.856

c)

0.99

d)

0.502

61.

250 mL of 1.5 M solution of sulphuric acid is diluted by adding 5L of water. The molarity of the diluted solution is:

a)

0.0926

b)

0.0823

c)

0.0714

d)

12

62.
What is the mass of 2.50 mol of oxygen gas O2?
a)
40 g
b)
80 g
c)
16 g
d)
32 g
63.

How many Mg atoms are present in 3.00 moles of MgCl2 ?

a)

1.81 x 10^24

b)

3.02 x 10^24

c)

12.0 x 10^25

d)

16.0 x 10^23

64.

Number of atoms in 52 g of He are:

a)

2.865 X 1023

b)

7.83 X 1024

c)

6.023 X 1023

d)

5000

65.

Which of the following statement is INCORRECT

a)

protium has no neutron

b)

C14 is used for finding age of old wooden objects

c)

Ca-40 and Ar-50 are isotopes

d)

Ca-40 and Ar -40 are isobars

66.

What is the mass percent of carbon in carbon dioxide?

a)

40

b)

27

c)

32

d)

10

67.

Which is used to Express amount of mercury vapour in atmosphere

a)

M

b)

m

c)

Mole fraction

d)

ppm

68.

Which subatomic part of an atom gives it a positive charge?

a)

Neutron

b)

Proton

c)

Electron

d)

Nucleus

69.

What is the smallest 'building block' of the elements that make up the universe?

a)

An atom

b)

An electron

c)

A proton

d)

A cell

70.

An atom of carbon has 6 protons and 7 neutrons in its nucleus. If the atom is neutral, how many electrons does it have?

a)

0

b)

7

c)

6

d)

13

71.

An atom of neon has 8 valence electrons. What will an atom of neon MOST likely do to be stable?

a)

Gain 1 electron

b)

Lose 2 electrons

c)

Lose 8 electrons

d)

Neither gain nor lose any valence electrons

72.

What type of bond is formed when atoms share electrons?

a)

Covalent

b)

Ionic

c)

Hydrogen

d)

Polyatomic

73.

Carbon has 4 valence electrons which means

a)

it can only form bonds with carbon

b)

it is stable

c)

it can make ionic bonds

d)

it wants to make 4 covalent bonds

74.

The electrons in the outermost energy level are called

a)

valence

b)

ions

c)

covalent

d)

farthest out

75.

Acids have more ______ ions than bases

a)

OH-

b)

H-

c)

OH+

d)

H+

76.

If salt is dissolved in water, water is the ____________

a)

Solution

b)

Solute

c)

Solvent

d)

Suspension

77.

Which of the following would be considered most acidic?

a)

1

b)

3

c)

7

d)

13

78.

The image shows the periodic grid for SODIUM. What is Sodium's atomic mass?

a)

11

b)

12

c)

23

d)

Impossible to tell

79.

What element will have the most similar physical and chemical properties to the element Sulfur (S)?

(click on the periodic table to expand it!)

a)

Carbon (C)

b)

Phosphorous (P)

c)

Oxygen (O)

d)

Neon (Ne

80.
What two elements make up water?
a)
Helium and oxygen
b)
Hydrogen and oxygen
c)
helium and carbon
d)
oxygen and carbon
81.

Which is more informative?

a)

Empirical Formula

b)

Molecular Formula

82.

What will be the molarity of a solution, which contains 5.85 g of NaCl(s) per

500 mL?

a)

4

b)

20

c)

0.2

d)

2

83.

The number of atoms present in one mole of an element is equal to Avogadro

number. Which of the following element contains the greatest number of

atoms?

a)

4g He

b)

46g Na

c)

0.4g Ca

d)

12g He

84.

Calculate the molecular mass of acetone (CH3COCH3 )

a)

46 g mol-1

b)

64 g mol-1

c)

58 g mol-1

d)

100 g mol-1

85.

What is the atomic number?

a)

the number of protons in the nucleus

b)

the number of protons and neutrons in the nucleus

c)

the number of neutrons in the nucleus

d)

the number of protons in the energy levels

86.

What is the mass number?

a)

the number of protons in the nucleus

b)

the number of protons and neutrons in the nucleus

c)

the number of neutrons in the nucleus

d)

the number of protons and electrons in the atom

87.

What is the atomic number of this atom?

a)

1

b)

3

c)

4

d)

7

88.
What does the C represent?
a)
atomic mass
b)
atomic number
c)
element name
d)
chemical symbol 
89.

An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.

a)

20

b)

10

c)

35

d)

25

90.

How many electrons does this atom have?

a)

2

b)

4

c)

6

d)

10

91.
The atomic number of an element that has 9 protons, 9 electrons, and 10 neutrons is _____.
a)
9
b)
10
c)
19
d)
28
92.
Where is most of the mass in an atom located?
a)
in the nucleus
b)
in the protons
c)
in the neutrons
d)
in the electrons
93.
Particles that have the same charge
a)
Attract
b)
Repel
c)
Show no action
d)
None of the above
94.

The atomic number of an atom is 22, therefore it has_______electrons

a)

11

b)

22

c)

44

d)

None of the above

95.
True or False
The electron has a mass of 1 amu
a)
True
b)
False
96.
The 1 st energy level contains 
a)
2 electrons
b)
4 electrons
c)
8 electrons 
d)
no electrons at all
97.
The 2nd energy level contains
a)
2 electrons
b)
4 electrons
c)
8 electrons
d)
18 electrons
98.
True or False
The neutron has zero charge 
a)
True
b)
False
99.
Value representing the number of protons in an element
a)
Atomic Mass
b)
Mass Number
c)
Valence Electrons
d)
Atomic Number
100.

What does the 6 represent?

a)

Atomic mass

b)

atomic number

c)

chemical symbol

d)

element name

101.

How many protons does indium have?

a)

49

b)

66

c)

114

d)

115

102.

Which scientist discovered the electron and proposed the model above (which looks like a chocolate chip cookie)?

a)

Dalton

b)

Thomson

c)

Rutherford

d)

Bohr

103.

Which scientist was the first to develop the idea of atomic theory?

a)

Dalton

b)

Thomson

c)

Rutherford

d)

Bohr

104.

Chadwick discovered:

a)

protons

b)

neutrons

c)

electrons

d)

quarks

105.
In Dalton's Atomic Theory, all elements consist of __________ that cannot be divided.
a)
Atoms
b)
Parts
c)
Molecules
d)
Hydrogen
106.

The cathode ray experiments led to which particle being discovered?

a)

Nucleus

b)

Proton

c)

Neutron

d)

Electron

107.

Number of moles of sugar in 547.2 gram are:


(Mol. mass of sugar = 342)

a)

1.6

b)

2.2

c)

342

d)

548

108.

The mass of 100 molecules of sucrose (C12H22O11) is_________.

a)

100 g

b)

342 g

c)

3.88 × 10–20 g

d)

5.68 × 10–20 g

109.

How many moles of methane are required to produce 22g of CO2(g) after combustion ?

a)

2 Moles

b)

1 Moles

c)

0.5 Moles

d)

0.05 Moles

110.

A solution is 25% water, 25% ethanol and 50% acetic acid by mass. The mole fraction of water is:

a)

0.6

b)

0.856

c)

0.99

d)

0.502

111.

250 mL of 1.5 M solution of sulphuric acid is diluted by adding 5L of water. The molarity of the diluted solution is:

a)

0.0926

b)

0.0823

c)

0.0714

d)

12

112.
What is the mass of 2.50 mol of oxygen gas O2?
a)
40 g
b)
80 g
c)
16 g
d)
32 g
113.

How many Mg atoms are present in 3.00 moles of MgCl2 ?

a)

1.81 x 10^24

b)

3.02 x 10^24

c)

12.0 x 10^25

d)

16.0 x 10^23

114.

Number of atoms in 52 g of He are:

a)

2.865 X 1023

b)

7.83 X 1024

c)

6.023 X 1023

d)

5000

115.

Which of the following statement is INCORRECT

a)

protium has no neutron

b)

C14 is used for finding age of old wooden objects

c)

Ca-40 and Ar-50 are isotopes

d)

Ca-40 and Ar -40 are isobars

116.

What is the mass percent of carbon in carbon dioxide?

a)

40

b)

27

c)

32

d)

10

117.

Which is used to Express amount of mercury vapour in atmosphere

a)

M

b)

m

c)

Mole fraction

d)

ppm

118.

Which subatomic part of an atom gives it a positive charge?

a)

Neutron

b)

Proton

c)

Electron

d)

Nucleus

119.

What is the smallest 'building block' of the elements that make up the universe?

a)

An atom

b)

An electron

c)

A proton

d)

A cell

120.

An atom of carbon has 6 protons and 7 neutrons in its nucleus. If the atom is neutral, how many electrons does it have?

a)

0

b)

7

c)

6

d)

13

121.

An atom of neon has 8 valence electrons. What will an atom of neon MOST likely do to be stable?

a)

Gain 1 electron

b)

Lose 2 electrons

c)

Lose 8 electrons

d)

Neither gain nor lose any valence electrons

122.

What type of bond is formed when atoms share electrons?

a)

Covalent

b)

Ionic

c)

Hydrogen

d)

Polyatomic

123.

Carbon has 4 valence electrons which means

a)

it can only form bonds with carbon

b)

it is stable

c)

it can make ionic bonds

d)

it wants to make 4 covalent bonds

124.

The electrons in the outermost energy level are called

a)

valence

b)

ions

c)

covalent

d)

farthest out

125.

Acids have more ______ ions than bases

a)

OH-

b)

H-

c)

OH+

d)

H+

126.

If salt is dissolved in water, water is the ____________

a)

Solution

b)

Solute

c)

Solvent

d)

Suspension

127.

Which of the following would be considered most acidic?

a)

1

b)

3

c)

7

d)

13

128.

The image shows the periodic grid for SODIUM. What is Sodium's atomic mass?

a)

11

b)

12

c)

23

d)

Impossible to tell

129.

What element will have the most similar physical and chemical properties to the element Sulfur (S)?

(click on the periodic table to expand it!)

a)

Carbon (C)

b)

Phosphorous (P)

c)

Oxygen (O)

d)

Neon (Ne

130.
What two elements make up water?
a)
Helium and oxygen
b)
Hydrogen and oxygen
c)
helium and carbon
d)
oxygen and carbon
131.

Which is more informative?

a)

Empirical Formula

b)

Molecular Formula

132.

What will be the molarity of a solution, which contains 5.85 g of NaCl(s) per

500 mL?

a)

4

b)

20

c)

0.2

d)

2

133.

The number of atoms present in one mole of an element is equal to Avogadro

number. Which of the following element contains the greatest number of

atoms?

a)

4g He

b)

46g Na

c)

0.4g Ca

d)

12g He

134.

Calculate the molecular mass of acetone (CH3COCH3 )

a)

46 g mol-1

b)

64 g mol-1

c)

58 g mol-1

d)

100 g mol-1

135.

What is the atomic number?

a)

the number of protons in the nucleus

b)

the number of protons and neutrons in the nucleus

c)

the number of neutrons in the nucleus

d)

the number of protons in the energy levels

136.

What is the mass number?

a)

the number of protons in the nucleus

b)

the number of protons and neutrons in the nucleus

c)

the number of neutrons in the nucleus

d)

the number of protons and electrons in the atom

137.

What is the atomic number of this atom?

a)

1

b)

3

c)

4

d)

7

138.
What does the C represent?
a)
atomic mass
b)
atomic number
c)
element name
d)
chemical symbol 
139.

An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.

a)

20

b)

10

c)

35

d)

25

140.

How many electrons does this atom have?

a)

2

b)

4

c)

6

d)

10

141.
The atomic number of an element that has 9 protons, 9 electrons, and 10 neutrons is _____.
a)
9
b)
10
c)
19
d)
28
142.
Where is most of the mass in an atom located?
a)
in the nucleus
b)
in the protons
c)
in the neutrons
d)
in the electrons
143.
Particles that have the same charge
a)
Attract
b)
Repel
c)
Show no action
d)
None of the above
144.

The atomic number of an atom is 22, therefore it has_______electrons

a)

11

b)

22

c)

44

d)

None of the above

145.
True or False
The electron has a mass of 1 amu
a)
True
b)
False
146.
The 1 st energy level contains 
a)
2 electrons
b)
4 electrons
c)
8 electrons 
d)
no electrons at all
147.
The 2nd energy level contains
a)
2 electrons
b)
4 electrons
c)
8 electrons
d)
18 electrons
148.
True or False
The neutron has zero charge 
a)
True
b)
False
149.
Value representing the number of protons in an element
a)
Atomic Mass
b)
Mass Number
c)
Valence Electrons
d)
Atomic Number
150.

What does the 6 represent?

a)

Atomic mass

b)

atomic number

c)

chemical symbol

d)

element name

151.

How many protons does indium have?

a)

49

b)

66

c)

114

d)

115

152.

Which scientist discovered the electron and proposed the model above (which looks like a chocolate chip cookie)?

a)

Dalton

b)

Thomson

c)

Rutherford

d)

Bohr

153.

Which scientist was the first to develop the idea of atomic theory?

a)

Dalton

b)

Thomson

c)

Rutherford

d)

Bohr

154.

Chadwick discovered:

a)

protons

b)

neutrons

c)

electrons

d)

quarks

155.
In Dalton's Atomic Theory, all elements consist of __________ that cannot be divided.
a)
Atoms
b)
Parts
c)
Molecules
d)
Hydrogen
156.

The cathode ray experiments led to which particle being discovered?

a)

Nucleus

b)

Proton

c)

Neutron

d)

Electron

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