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Redox review

Total questions: 60

Worksheet time: 2hrs 8mins

Name
Class
Date
1.
Zinc reacts with steam to form zinc oxide and hydrogen. 
Zn + H2O ------> ZnO + H2   During the reaction, which substance is oxidised?  
a)
hydrogen  
b)
water  
c)
zinc            
d)
zinc oxide
2.
Which equation shows an oxidation reaction?
a)
A
b)
B
c)
C
d)
D
3.
This is the half reaction for: 
Sn(s) → Sn4+(aq) + 4e−
a)
redox
b)
reduction
c)
oxidation
d)
neutralization
4.
Which change is reduction?
a)
change 1
b)
change 2
c)
neither
5.
What is the oxidation number of carbon in NaHCO3?
a)
+1
b)
+4
c)
-4
d)
+6
6.
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
7.
Sodium reacts with sulphur to form sodium sulphide.  
2Na + S →Na2S This is an example of:
a)
decomposition
b)
synthesis
c)
single  replacement
d)
precipitation
8.
Which expression represents the oxidation of the copper(I) ion?
a)
Cu+---->  Cu2+ + e–  
b)
Cu ----> Cu+ + e– 
c)
Cu+ + e– ----> Cu0
d)
Cu+ + e– ----> Cu2+
9.
Is calcium oxidized or reduced in the following reaction? 
2CaO--> 2Ca + O2
a)
Oxidized
b)
Reduced
10.
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+
11.
What is oxidation number of Fe in FeO ?
a)
+2
b)
-2
c)
0
d)
+1
12.
What is the oxidizing agent of this reaction?
2Al(s) + 6H+(aq) −−−> 2Al3+ (aq) + 3H2(g)
a)
H2
b)
Al3+
c)
Al
d)
H+
13.
What is oxidation number of H in H2O?
a)
0
b)
-2
c)
-1
d)
+1
14.
What is oxidation number of Cr in Cr2O72-?
a)
-2
b)
+2
c)
+6
d)
+12
15.
What is oxidation number of O in O2 ?
a)
0
b)
-2
c)
+1
d)
+2
16.
If in a reaction, copper is reduced; its number of electrons has:
a)
Increased
b)
Decreased
c)
Remained Constant
d)
Varies Randomly
17.
What is the oxidation number of N in NO2-1?
a)
-3
b)
+4
c)
-2
d)
+3
18.
What is the reducing agent of this reaction?
3Mg + N2−−−−> Mg3N2
a)
Mg
b)
N2
c)
Mg3N2
d)
MgN
19.
If an atom loses electrons during a chemical reaction, the atom was:
a)
Oxidized
b)
Reduced
c)
Neutralized
d)
Precipitated
20.
Another name for a "oxidation-reduction" reaction is
a)
chemical reaction
b)
neutralization reaction
c)
redox reaction
d)
nuclear reaction
21.
What is oxidation number of O in H2O2 ?
a)
-2
b)
-1/2
c)
+1
d)
-1
22.
Reduction involves 
a)
gaining electrons; gaining oxygen
b)
losing electrons; losing oxygen
c)
gaining electrons, losing oxygen
d)
losing electrons; gaining oxygen
23.
What element is being Oxidized?
a)
N
b)
H
c)
O
d)
S
24.
What element is being Reduced?
a)
N
b)
H
c)
O
d)
S
25.
     In the reaction Zn + H2O --> ZnO2 + H2
 which element, if any, is oxidized? 
a)
Zinc
b)
Hydrogen
c)
Oxygen
d)
None
26.
What does OIL RIG mean?
a)
It's a pump used to remove oil from the ground
b)
Oxidation is losing protons, reduction is gaining protons
c)
Oxidation is losing electrons, reduction is gaining electrons
d)
Who knows?
27.
What is oxidation number of H in CaH2?
a)
+1
b)
-1
c)
0
d)
+2
28.
What is oxidation number of P in K3PO4?
a)
+1
b)
+5
c)
-2
d)
0
29.
What happens to Cr3+ ion when it is converted to CrO42–
a)
Oxidation number decreases and it undergo reduction
b)
Oxidation number decreases and it undergo oxidation
c)
Oxidation number increases and it undergo reduction
d)
Oxidation number increases and it undergo oxidation
30.
As a free element (uncombined), oxygen will have an oxidation number of ?
a)
+1
b)
-1
c)
0
d)
+2
31.
What is the charge of an ion in group 2?
a)
+2
b)
-6
c)
-2
d)
+6
32.

What is the oxidation number of nickel in NiSO3?

a)

+2

b)

+3

c)

0

d)

-1

33.

H2 + 2 AgNO3 → 2 Ag + 2 HNO3

Which element is being oxidized in the equation above?

a)

H

b)

Ag

c)

N

d)

O

34.

Mn2+ → MnO4-

The ON of Mn in Mn2+ is +2. The ON of Mn in MnO4- is +7. Has this species been oxidised or reduced?

a)

Oxidised

b)

Reduced

35.

What is the oxidation number for P in H3PO4?

a)

+3

b)

+5

c)

+4

d)

+6

36.

Determine the oxidation number of iron in FeCl3.

a)

0

b)

+1

c)

+2

d)

+3

37.

During an oxidation-reduction reaction, the number of electrons gained is

a)

equal to the number of electrons lost

b)

less than the number of electrons lost

c)

equal to the number of protons gained

d)

less than the number of protons gained

38.

Which are examples of reduction?

a)

I and II

b)

II and III

c)

I and III

d)

I, II and III

39.
Which statement is correct?
a)
H2SO3 is reducing agent because it undergoes reduction.
b)
H2SO3 is reducing agent because it undergoes oxidation.
c)
Sn4+ is oxidizing agent because it undergoes oxidation
d)
Sn4+ is reducing agent because it undergoes oxidation
40.
What happens to iodine when iodate, IO3–, converted to iodine, I2?
a)
Undergo reduction and oxidation number changes from –1 to 0
b)
Undergo oxidation and oxidation number changes from –1 to 0
c)
Undergo reduction and oxidation number change from +5 to 0
d)
Undergo oxidation and oxidation number change from +5 to 0
41.
What are the oxidation numbers for SO42-
a)
S: 6+   O: 2-
b)
S: 8+   O: 2-
c)
S: 6-   O: 2+
d)
S: 8-   O: 2-
42.

What is the oxidation number of nitrogen in N2?

a)

-3

b)

0

c)

+4

d)

-1

43.

The sum of the oxidation numbers in Na2CO3 is equivalent to

a)

0

b)

-2

c)

+1

d)

-1

44.
What coefficient would Fe+2 have in the following reaction?
___ Al + ___ Fe+2 → ___ Al+3 + ___ Fe
a)
1
b)
2
c)
3
d)
6
45.
Which of the following reactions is balanced by both mass and charge?
a)
Fe+2 + Al →Fe + Al+3
b)
Cu + Fe+2 → Cu+1 + Fe+3
c)
F2 + Br- --> F- + Br2
d)
Fe+2 + 2 Cu --> 2 Cu+ + Fe
46.
Which of the following is the balanced half -reaction for the oxidation of Cu to Cu+2?
a)
Cu   --> Cu+2
b)
Cu + 2 e-   --> Cu+2
c)
Cu  --> Cu+2  + 2 e-
d)
Cu - 2e-  --> Cu+2
47.
Which of the following will always have an oxidation number of +1 when in a compound?
a)
Mg
b)
Ca
c)
Na
d)
S
48.
Oxygen always has an oxidation number of...
a)
-1
b)
1
c)
2
d)
-2
49.

Which process involves the transfer of electrons?

a)

double replacement

b)

neutralization

c)

oxidation-reduction

d)

sublimation

50.

Which of these equations represents a redox reaction?

a)

Ca(HCO3)2 --> CaCO3 + H2O + CO2

b)

HC2H3O2 + NaOH --> NaC2H3O2 + H2O

c)

Zn + 2FeCl3 --> ZnCl2 + 2FeCl2

d)

NaCl + AgNO3 --> AgCl + NaNO3

51.

A decrease in oxidation number.

a)

concentrated

b)

reduction

c)

oxidation

d)

dilute

52.

An increase in oxidation number.

a)

more acidic

b)

reduction

c)

less basic

d)

oxidation

53.

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

54.

Combustion and single-replacement reactions are __________ redox reactions.

a)

always

b)

never

c)

sometimes

d)

mostly

55.

Combustion and single-replacement reactions are __________ redox reactions.

a)

always

b)

never

c)

sometimes

d)

mostly

56.

These keep track of the movement of electrons.

a)

(+) and (-) signs

b)

oxidation numbers

c)

coefficients

d)

subscripts

57.

Substance that oxidizes another substance by accepting its electrons.

a)

reducing agent

b)

oxidation number

c)

combustion

d)

oxidizing agent

58.

Substance that reduces another substance by losing electrons.

a)

reducing agent

b)

half-reaction

c)

electronegative atom

d)

oxidizing agent

59.

Substance that reduces another substance by losing electrons.

a)

reducing agent

b)

half-reaction

c)

electronegative atom

d)

oxidizing agent

60.

Which types of reaction is never a redox reaction?

a)

Single replacement

b)

Decomposition

c)

Double replacement

d)

Combustion

e)

Acid/Base Reaction

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