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oxidation/ reduction reactions

Total questions: 83

Worksheet time: 47mins

Name
Class
Date
1.
Another name for a "oxidation-reduction" reaction is
a)
chemical reaction
b)
neutralization reaction
c)
redox reaction
d)
nuclear reaction
2.

Oxidation is the _________ of electrons.

a)

loss

b)

gain

c)

sharing

d)

transfer

3.

Reduction is the ___________ of electrons.

a)

loss

b)

gain

c)

sharing

d)

transfer

4.

Gaining hydrogen is an example of...

a)

oxidation

b)

reduction

5.

Gaining oxygen is an example of...

a)

oxidation

b)

reduction

6.

In a redox reaction, the species reduced

a)

gains electrons and is the oxidizing agent

b)

loses electrons and is the oxidizing agent

c)

loses electrons and is the reducing agent

d)

gains electrons and is the reducing agent

7.
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
8.
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+
9.

In a reaction, copper is reduced; its number of electrons has:

a)

Increased

b)

Decreased

c)

Remained Constant

d)

Varies Randomly

10.
If an atom loses electrons during a chemical reaction, the atom was:
a)
Oxidized
b)
Reduced
c)
Neutralized
d)
Precipitated
11.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
12.

In a redox reaction, spectator ions...

a)

become oxidised

b)

become reduced

c)

remain unchanged

13.

Which of the following is NOT a redox reaction?

a)

Displacement

b)

Decomposition

c)

Synthesis

d)

Neutralisation

e)

Combustion

14.

Which of the following is NOT a redox reaction?

a)

Displacement

b)

Decomposition

c)

Synthesis

d)

Neutralisation

e)

Combustion

15.

Substance that oxidizes another substance by accepting its electrons.

a)

reducing agent

b)

oxidation number

c)

combustion

d)

oxidizing agent

16.
     In the reaction Zn + H2O --> ZnO2 + H2
 which element, if any, is oxidized? 
a)
Zinc
b)
Hydrogen
c)
Oxygen
d)
None
17.
What substance is oxidized in the following reaction?
4Fe + 3O2 --> 2Fe2O3
a)
Iron
b)
Fluorine
c)
Oxygen
18.
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
19.

In a reaction, copper is reduced; its number of electrons has:

a)

Increased

b)

Decreased

c)

Remained Constant

d)

Varies Randomly

20.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
21.

Substance that oxidizes another substance by accepting its electrons.

a)

reducing agent

b)

oxidation number

c)

combustion

d)

oxidizing agent

22.
     In the reaction Zn + H2O --> ZnO2 + H2
 which element, if any, is oxidized? 
a)
Zinc
b)
Hydrogen
c)
Oxygen
d)
None
23.
What substance is oxidized in the following reaction?
4Fe + 3O2 --> 2Fe2O3
a)
Iron
b)
Fluorine
c)
Oxygen
24.

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

a)

a chemical reaction

b)

redox

c)

oxidation

d)

reduction

25.

Substance that oxidizes another substance by accepting its electrons.

a)

reducing agent

b)

oxidation number

c)

combustion

d)

oxidizing agent

26.

Substance that reduces another substance by losing electrons.

a)

reducing agent

b)

half-reaction

c)

electronegative atom

d)

oxidizing agent

27.

The element sodium (Na) is a soft solid that will react explosively with water. The element chlorine (Cl) is a toxic gas. When these two elements combine, they produce a stable, crystalline solid known commonly as table salt (NaCl).


How would you explain this?


El elemento sodio (Na) es un sólido blando que reacciona explosivamente con el agua. El elemento cloro (Cl) es un gas tóxico. Cuando estos dos elementos se combinan, producen un sólido cristalino estable conocido comúnmente como sal de mesa (NaCl). ¿Cómo explicarías esto?

a)

When substances combine to form new substances, the properties of the reactants are preserved.

b)

The properties of each of the two original elements are combined to give salt its properties.

c)

Sodium and chlorine become different elements during the reaction.

d)

When substances combine to form new substances, the properties of the resulting substances will be different.

28.

Harrison is making cake. He prepares some batter and places it into the oven. Harrison realizes a gas, carbon dioxide, is coming out of the batter as it bakes.


Harrison está haciendo pastel. Prepara un batido y lo mete en el horno. Harrison se da cuenta de que sale gas, dióxido de carbono, de la masa mientras se hornea.


Which options are true about carbon dioxide?

¿Qué opciones son ciertas sobre el dióxido de carbono?

a)

It is a new gas that forms during baking.

b)

It is made of atoms that did not exist before.

c)

It is the dough changing states from solid to gas.

d)

It is formed from the atoms of the batter

29.

Which of the following describes the law of conservation of mass?


¿Cuál de los siguientes describe la ley de conservación de la masa?

a)

The mass of the reactants is greater than the mass of the products.

b)

The mass of the products equals the mass of the reactants.

c)

The mass of the products is greater than the mass of the reactants.

d)

The products will have the same states of matter as the reactants.

30.

In a chemical reaction, the mass of the reactants is 65.3 grams. The reaction produces two products, and the mass of Product 1 is 25.3 grams. What is the mass of the second product?

a)

40 grams.

b)

7.2 grams.

c)

35 grams.

d)

42 grams.

31.

In a chemical reaction, the mass of the reactants is 200 grams. Which of the following could represent the mass of the products?

a)

26.6 grams.

b)

200 grams

c)

3.3 grams.

d)

2000 grams.

32.

In the reaction


4 NH3 + 5 O2 → 4 NO + 6 H2O


the oxidation number of nitrogen changes from

a)

–2 to –3

b)

–2 to +3

c)

–3 to –2

d)

–3 to +2

33.

What is the oxidation number of chromium in K2Cr2O7 ?

a)

+12

b)

+2

c)

+3

d)

+6

34.

In which substance does hydrogen have an oxidation number of zero?

a)

LiH

b)

H2O

c)

H2S

d)

H2

35.

In which substance is the oxidation number of Cl equal to +1?

a)

Cl2

b)

Cl2O

c)

AlCl3

d)

HClO2

36.

What is the oxidation state of phosphorus in the

compound Na3PO3?

a)

0

b)

-3

c)

+3

d)

+5

37.

What is the oxidation state of phosphorus in the

compound Na3PO3?

a)

0

b)

-3

c)

+3

d)

+5

38.

In which compound does hydrogen have an oxidation state of –1?

a)

NaH

b)

HCl

c)

H2O

d)

NH3

39.

Oxygen has an oxidation number of –2 in

a)

O2

b)

NO2

c)

Na2O2

d)

OF2

40.

Oxygen has an oxidation number of –2 in

a)

O2

b)

NO2

c)

Na2O2

d)

OF2

41.

Given the reaction:


Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)


The oxidation number of Zn(s) increases because it

a)

loses electrons

b)

gains electrons

c)

loses protons

d)

gains protons

42.

Given the reaction:


Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)


The oxidation number of Zn(s) increases because it

a)

loses electrons

b)

gains electrons

c)

loses protons

d)

gains protons

43.

Which change in oxidation number represents reduction?

a)

–1 to +1

b)

–1 to –2

c)

–1 to +2

d)

–1 to 0

44.

Given the reaction:


F2(g) + 2 Br–(aq) → Br2() + 2 F–(aq)


Which species is reduced?

a)

F2(g)

b)

Br–(aq)

c)

Br2 (l)

d)

F–(aq)

45.

Given the oxidation-reduction reaction:


H2 + 2 Fe+3 → 2 H+ + 2 Fe+2


Which species undergoes reduction?

a)

H2

b)

Fe3+

c)

H+

d)

Fe2+

46.

Given the cell reaction:


Ca(s) + Mg2+(aq) → Ca2+(aq) + Mg(s)


Which substance was oxidized?

a)

Ca(s)

b)

Mg2+(aq)

c)

Ca2+(aq)

d)

Mg(s)

47.

In the reaction


2 Fe3+ + S2– → 2 Fe2+ + S0,


the species oxidized is

a)

Fe3+

b)

S2–

c)

Fe2+

d)

S0

48.

In a redox reaction, the species reduced

a)

gains electrons and is the oxidizing agent

b)

gains electrons and is the reducing agent

c)

loses electrons and is the oxidizing agent

d)

loses electrons and is the reducing agent

49.

In the reaction


2 Mg + O2 → 2 MgO


the magnesium is the

a)

oxidizing agent and is reduced

b)

oxidizing agent and is oxidized

c)

reducing agent and is reduced

d)

reducing agent and is oxidized

50.

Given the redox reaction:


Fe2+(aq) + Zn(s) → Zn2+(aq) + Fe(s)


Which species acts as a reducing agent?

a)

Fe(s)

b)

Fe2+(aq)

c)

Zn(s)

d)

Zn2+(aq)

51.

Which half-reaction correctly represents oxidation?

a)

Sn2+ + 2e– → Sn0

b)

Sn4+ + 2e– → Sn2+

c)

Sn2+ → Sn0 + 2e–

d)

Sn2+ → Sn4+ + 2e–

52.

Which balanced equation represents an oxidation-reduction reaction?

a)

AgNO3 + NaCl → AgCl + NaNO3

b)

BaCl2 +K2CO3 → BaCO3 +2KCl

c)

CuO + CO → Cu + CO2

d)

HCl + KOH → KCl + H2O

53.

Which balanced equation represents an oxidation-reduction reaction?

a)

Ba(NO3)2 + Na2SO4 →BaSO4 + 2NaNO3

b)

H3PO4 + 3KOH →K3PO4 + 3H2O

c)

Fe(s) + S(s) →FeS(s)

d)

NH3(g) + HCl(g) →NH4Cl(s)

54.

What is the oxidation number of nitrogen in HNO2?

a)

-1

b)

-2

c)

+3

d)

+4

55.

What is the oxidation number assigned to manganese in KMnO4?

a)

+7

b)

+2

c)

+4

d)

+3

56.

In which substance does sulfur have a negative oxidation number?

a)

S

b)

CaSO4

c)

Na2S

d)

SO2

57.

Given the electrochemical cell reaction:

 Zn(s) + Ni2+ (aq) → Zn2+ (aq) + Ni(s)

Which species is the reducing agent?

a)

Ni2+

b)

Zn

c)

Ni

d)

Zn2+

58.

In a redox reaction, the species reduced

a)

gains electrons and is the oxidizing agent

b)

loses electrons and is the oxidizing agent

c)

loses electrons and is the reducing agent

d)

gains electrons and is the reducing agent

59.

What element is an oxidizing agent?

a)

Na

b)

Ca

c)

K

d)

a. F2

60.

Which half-reaction correctly represents reduction?

a)

S2– → S + 2e–

b)

Mn7+ → Mn4+ + 3e–

c)

Mn7+ + 3e– → Mn4+

d)

S2– + 2e– → S

61.

The oxidation number of Hydrogen in KH potassium hydride equals:

a)

-2

b)

-1

c)

+1

d)

+2

62.

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

63.

Combustion and single-replacement reactions are __________ redox reactions.

a)

always

b)

never

c)

sometimes

d)

mostly

64.

_____________ synthesis and decomposition reactions involve the transfer of electrons.

a)

All

b)

Most

c)

No

d)

Some

65.

Defined as the loss of electrons.

a)

oxidation

b)

reduction

c)

redox

d)

OIL RIG

66.

Defined as the gain of electrons.

a)

oxidation

b)

redox

c)

reduction

d)

LEO GER

67.

These keep track of the movement of electrons.

a)

(+) and (-) signs

b)

oxidation numbers

c)

coefficients

d)

subscripts

68.

An increase in oxidation number.

a)

more acidic

b)

reduction

c)

less basic

d)

oxidation

69.

A decrease in oxidation number.

a)

concentrated

b)

reduction

c)

oxidation

d)

dilute

70.

What is the oxidation number of C in SrCO3?

a)

-4

b)

+2

c)

-6

d)

+4

71.

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

a)

N2

b)

H2

c)

NH3

d)

2NH3

72.

When Lead Nitrate reacts with potassium iodide, Yellow precipitate of ............. is formed

a)

PbI2

b)

KNO3

c)

Pb(NO3)2

d)

PbIO3

73.

Which of the following is an example of displacement reaction?

a)

2 KClO3→KCl + O2

b)

2H2 + O2 →2 H2O

c)

Zn + 2 HCl → ZnCl2 + H2

d)

N2 + 3 H2 → 2 NH3

74.

What is the oxidation state of Cl in ClO- ?

a)

0

b)

+1

c)

-1

d)

+2

75.

What is the oxidation state of Cu in Cu2+?

a)

-1

b)

-2

c)

+2

d)

0

76.

What is the oxidation state of H in H2?

a)

+2

b)

+1

c)

0

d)

None of the above

77.

What is the oxidation state of Pb in PbO ?

a)

+2

b)

+4

c)

0

d)

-2

78.

C in CO32-?

a)

-4

b)

+2

c)

0

d)

+4

79.

S in HSO4- ?

a)

+5

b)

-6

c)

+6

d)

+2

80.

H in NaH ?

a)

+1

b)

0

c)

-1

d)

None of the above

81.

Is this oxidation or reduction: SO42- becomes SO2

a)

Oxidation

b)

Reduction

c)

Neither

d)

Both

82.

What type of reaction is this: C2H2 becomes C2H6

a)

Reduction

b)

Oxidation

c)

Neither

d)

Combustion

83.

What type of reaction is this: SF4 becomes SF6

a)

Hydrogenation

b)

Reduction

c)

Oxidation

d)

None of the above

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