Oxidation Number, Rules for Assigning Oxidation Number NEET Questions

Physical Chemistry - Redox Reactions and Electrochemistry

Oxidation Number, Rules for Assigning Oxidation Number MCQ Questions


1.
The oxidation number of an atom in its free or uncombined elemental state is:
A.
Equal to its group number
B.
-1
C.
Zero
D.
+1
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ANSWER :
C. Zero
2.
Which of the following has oxidation number zero for the underlined atom?
A.
P̲₂O₅
B.
H₃P̲O₄
C.
P̲₄ (white phosphorus)
D.
P̲H₃
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ANSWER :
C. P̲₄ (white phosphorus)
3.
What is the oxidation state of S in S₈ (rhombic sulphur)?
A.
+8
B.
-2
C.
+2
D.
0
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ANSWER :
D. 0
4.
Oxidation number of O in O₃ (ozone) is:
A.
-2
B.
-1
C.
+2
D.
0
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ANSWER :
D. 0
5.
The oxidation number of a monatomic ion equals:
A.
Atomic number minus group number
B.
The charge on the ion
C.
Always +1 for cations
D.
Group number of the element
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ANSWER :
B. The charge on the ion
6.
Oxidation number of Fe³⁺ is:
A.
-3
B.
+2
C.
+3
D.
0
😑 View Answer Rough Work Error
ANSWER :
C. +3