wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

REDOX reactions

Total questions: 18

Worksheet time: 23mins

Name
Class
Date
1.

Oxygen mostly has an oxidation number of...

a)
-1
b)
1
c)
2
d)
-2
2.
Is calcium oxidized or reduced in the following reaction? 
2CaO--> 2Ca + O2
a)
Oxidized
b)
Reduced
3.
In the reaction
2Ca(s) + O2(g) --> 2CaO(s), calcium is __________
a)
Reduced
b)
Synthesized
c)
Oxidized
d)
None of the above
4.
What is oxidation number of H in CaH2?
a)
+1
b)
-1
c)
0
d)
+2
5.

An increase in oxidation number.

a)

more acidic

b)

reduction

c)

less basic

d)

oxidation

6.

The sum of the oxidation numbers in SCN- is equivalent to

a)

0

b)

-1

c)

+1

d)

+3

7.
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+
8.

Reduction is when a substance ___

a)

gains protons

b)

loses protons

c)

gains electrons

d)

loses electrons

9.

The "OIL" in "OILRIG" stands for: ___

a)

oxidation is loss of electrons

b)

oxidation is loss of protons

c)

only in lieu of reactions

d)

Office of Immigration Litigation

10.

When you study redox reactions it's absolutely essential to keep track of ___

a)

the pesos

b)

the electrons

c)

the element symbols

d)

the dollars

11.

The oxidation number of hydrogen, in the diatomic molecule H2, is ___

a)

0

b)

1

c)

-1

d)

2

12.

The oxidation number of sulfur in S8, its most common allotrope, is ___

a)

0

b)

1

c)

-8

d)

8

13.
What is oxidation number of Fe in FeO ?
a)
+2
b)
-2
c)
0
d)
+1
14.

What is the oxidation number of N in NO2-1?

a)
-3
b)
+4
c)
-2
d)
+3
15.
     In the reaction Zn + H2O --> ZnO2 + H2
 which element, if any, is oxidized? 
a)
Zinc
b)
Hydrogen
c)
Oxygen
d)
None
16.
What substance is oxidized in the following reaction?
4Fe + 3O2 --> 2Fe2O3
a)
Iron
b)
Fluorine
c)
Oxygen
17.

What is the oxidation number of Cr in Cr2O72- ?

a)

+14

b)

+6

c)

-6

d)

-14

18.

Name the oxidising agent in the following reaction:

nitrogen + hydrogen -> ammonia

a)

nitrogen

b)

hydrogen

c)

ammonia