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101 questions on oxidation numbers

Total questions: 101

Worksheet time: 3hrs 37mins

Name
Class
Date
1.
What is oxidation number of P in K3PO4?
2.
What is oxidation number of Cr in
Cr2O72-?
3.

What is the oxidation number of S in SO2-  ?

4.
What is the oxidation number of Ca in Ca3N2?
5.
What is oxidation number of Mn in MnO2 ?
6.

What element's don't have oxidation numbers? (a)  

Choose from the below words
alkali metals
noble gases
halogens
alkaline earth metals
7.
What is the oxidation of C in CH4?
8.
What is the oxidation number of N in NO21- ?
9.

Oxidation number of O in the compound H2O2:

10.

What is the total sum of oxidation numbers in the following compound Li3PO4?

11.

Oxidation number of Fe in Fe2O3:

12.

Oxidation number of H in NaH:

13.

What is the oxidation state of vanadium in V(H2O)63+ (a)  

Choose from the below words
1+
3+
5+
7+
14.

What is the oxidation state of phosphorous in Mg3(PO4)2

15.

What is the oxidation state of Cl in ClO- ?

16.

What is the oxidation number of Na+

17.

What is the oxidation state of Cr in CrO42- ?

18.

C in CO32-?

19.

S in HSO4- ?

20.

H in NaH ?

21.

What type of reaction is this: SF4 becomes SF6

a)

Hydrogenation

b)

Reduction

c)

Oxidation

d)

None of the above

22.

Oxidation number of in C2H2

23.

Is this oxidation or reduction: SO42- becomes SO2 (a)  

Choose from the below words
Oxidation
Reduction
Neither
Both
24.

Oxidation number of S in H2S:

25.

Oxidation number of S in SO2:

26.

What is the oxidation state of S in SO3 ?

27.

Oxidation number of O in the ion H3O+:

28.

Oxidation number of S in S8:

29.

Oxidation number of H in HNO3:

30.

What is the total oxidation number of elements in H2SO4?

31.

Oxidation number of N in NO:

32.

Oxidation number of N in NH4+:

33.

Oxidation number of N in N2O4:

34.

What is oxidation number of potassium in K3PO4?

35.

What is oxidation number of Mn in Mn2O3 ?

36.

Oxidation number of N in N2O5: (a)  

Choose from the below words
none of them
+2
3+
+4
37.

Oxidation number of C in C3H8

(a)  

38.

Oxidation number of C in C2H6

39.

Oxidation number of C in C2H4

40.

Oxidation number of C in CH2O

41.

Give the oxidation state of H in CaH2

42.

What is the oxidation state of P in P2O3 ?

43.

What is the oxidation state of P in P2O5 ?

44.

What is the oxidation state of P in P4O10 ?

45.

What is the oxidation state of P in P4O6 ?

46.

Oxidation number of C in CH2O2

47.

In NCl3, Chlorine has an oxidation number of (a)  

Choose from the below words
1-
1+
3-
3+
48.

In NCl3, Nitrogen has and oxidation Number of (a)  

Choose from the below words
3-
3+
1-
1+
49.

In CF4, Flourine has an oxidation number of

50.

In OF2 what is Oxygens Oxidation Number?

51.

In CO2, oxygen has an oxidation number of what?

52.

In H2O2, hydrogen has an oxidation number of

53.

In LiH, hydrogen has an oxidation number of

54.

In ClO3-, what is chlorine's oxidation number?

55.

Choose the correct oxidation numbers for HCl

a)

-1,+1

b)

+1,-1

c)

+2,-2

d)

-2,+2

56.

Choose the oxidation numbers for each atom in P4O10

a)

+5, -2

b)

-5,+2

c)

+2,-5

d)

-2,+5

57.

Assign oxidation numbers to each atom in HClO3

a)

+1, +5, -2

b)

+1, -5, -2

c)

+1, -3, -2

d)

-1, +5, -2

58.

What is the charge, or oxidation number, for elements in Group 2?

a)

-2

b)

+2

c)

-3

59.

C in CO32-?

60.

Give the oxidation number of Nitrogen and Oxygen in N2O molecule.

a)

Nitrogen +1, Oxygen -2

b)

Nitrogen -1, Oxygen -2

c)

Nitrogen +2, Oxygen -2

d)

Nitrogen -3, Oxygen -2

61.

Give the oxidation number for the underlined atoms below.

62.

Give the oxidation number for the underlined atoms below.

63.

Give the oxidation number for the underlined atoms below.

a)

+4

b)

-4

c)

+2

d)

-2

64.

Indicate the oxidation number of phosphorus in the given molecule.

65.

Determine the oxidation number of the nitrogen atom.

66.

Determine the oxidation number of manganese in MnO2

67.

Determine the oxidation number of manganese in MnCl2

68.

In the compounds, VO2+ , VO2+ , V3+ and V2+, what is the order of oxidation states of Vanadium?

a)

+5, +4, +2, +3

b)

+4, +5, +2, +3

c)

+5, +4, +3, +2

d)

+4, +4, +3, +2

69.

What is the oxidation number of Mn in MnO4- ?

70.

What is the oxidation number of Fe in FeCl3?

71.

What is the oxidation number of Cl in FeCl3?

72.

What is the oxidation state of H in H2?

73.

In a compound, what is the usual oxidation state of hydrogen?

74.

In a compound, what is the usual oxidation state of oxygen?

75.

In hydrogen peroxide, H2O2, what is the oxidation state of oxygen?

a)

0

b)

-1

c)

-2

76.

What is the oxidation state of Fe in Fe2O3 ?

77.

What is the oxidation state of Br in Br2 ?

78.

What is the oxidation state of S in MgSO4 ?

79.

The oxidation number of any uncombined element is ___

a)

0

b)

+1

c)

-1

d)

+2

80.

The oxidation number of fluorine in a compound is always ___

a)

+1

b)

+2

c)

-2

d)

-1

81.

The oxidation number of a monatomic ion equals the (a)   on the ion

82.

The sum of the oxidation numbers of all atoms in a polyatomic ion equals the (a)   of the ion

83.

Oxygen has an oxidation number of -2 unless it is combined with F (when it is ______), or it is in a peroxide (such as H2O2 or Na2O2), when it is -1

84.

In compounds, the elements of groups 1 and 2 as well as aluminum have oxidation numbers of

________________ respectively

a)

+1, -2, and +3

b)

-1, +2, and -3

c)

+1, +2, and +3

d)

+1, +3, and +4

85.

What is the oxidation state of each element in the following molecule: H2SO4

a)

H:1+ S:4+ O:2-

b)

H:1+ S:6+ O:1-

c)

H:1+ S:6+ O:2-

d)

H:1+ S:5+ O:2-

86.

What is the oxidation number for oxygen in dilithium dioxide Li2O2?

a)

0

b)

+2

c)

-2

d)

+1

e)

-1

87.

What is the oxidation number of fluorine in carbon tetrafluoride CF4?

a)

-2

b)

-1

c)

-3

d)

+2

e)

+1

88.

What is the oxidation number of hydrogen in boron trihydride BH3?

a)

0

b)

+1

c)

-1

d)

+2

e)

-2

89.

What is the oxidation number for lithium in dilithium dioxide Li2O2?

a)

0

b)

+2

c)

-2

d)

+1

e)

-1

90.

What is the oxidation number of iodine in KIO3?

a)

0

b)

-1

c)

+5

d)

+1

91.

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

a)

0

b)

-1

c)

+1

d)

+3

92.

What is the oxidation number of chlorine in HClO?

a)

0

b)

-1

c)

+1

d)

+5

93.

What is the total of all the oxidation states in ammonium dichromate: (NH4)2Cr2O7?

(a)  

94.

What is the oxidation state of oxygen in H2SO4?

(a)  

95.

What is the oxidation state of sulfur in a sulfide ion?

a)

+2

b)

+1

c)

-1

d)

-2

96.

What is the oxidation state of chlorine in a chloride ion?

a)

+1

b)

0

c)

-1

97.

What are the oxidation states of Hydrogen and Fluorine in HF?

a)

H = -1

F = +1

b)

H = +2

F = -2

c)

H = 0

F = 0

d)

H = +1

F = -1

98.

What is the oxidation state of Copper in Cu2O and CuO?

a)

Cu2O = +2

CuO = +1

b)

Cu2O = +1

CuO = +2

c)

Cu2O = +2

CuO = +2

d)

Cu2O = +1

CuO = +1

99.

What is the oxidation state of Iron in Fe(OH)3?

(a)  

100.

In the thiosulfate ion, S2O32-, what is the oxidation state of the sulfur?

(a)  

101.

Oxidation number of W in WO3?

a)

+2

b)

-2

c)

+4

d)

+6