3.3.3.0: Formal Charge and Oxidation State (Problems)
PROBLEM \(\PageIndex{1}\)
Determine the formal charge and oxidation state of each element in the following:
a. HCl
b. CF
4
c. PCl
3
- Answer a
-
FC: H: 0, Cl: 0
OX: H: +1, Cl: -1
- Answer b
-
FC: C: 0, F: 0
OX: C: +4, F: -1
- Answer c
-
FC: P: 0, Cl: 0
OX: P: +3, Cl: -1
PROBLEM \(\PageIndex{2}\)
Determine the formal charge and oxidation state of each element in the following:
a. H
3
O
+
b. \(\ce{SO4^2-}\)
c. NH
3
d. \(\ce{O2^2-}\)
e. H
2
O
2
- Answer a
-
FC: H: 0, O: +1
OX: H: +1, O: -2
- Answer b
-
FC: S: +2, O: -1
OX: S: +6, O: -2
- Answer c
-
FC: N: 0, H: 0
OX: N: -3, H: +1
- Answer d
-
FC: -1
OX: -1
- Answer e
-
FC: O: 0, H: 0
OX: O: -1, H: +1
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PROBLEM \(\PageIndex{3}\)
Calculate the formal charge and oxidation state of chlorine in the molecules Cl 2 and CCl4.
- Answer
-
FC: Cl in Cl 2 : 0; Cl in CCl 4 : 0
OX: Cl in Cl 2 : 0; Cl in CCl 4 : -1
PROBLEM \(\PageIndex{4}\)
Calculate the formal charge and oxidation state of each element in the following compounds and ions:
a. F
2
CO
b. NO
–
c. \(\ce{BF4-}\)
d. \(\ce{SnCl3-}\)
e. H
2
CCH
2
f. \(\ce{PO4^3-}\)
- Answer a
-
FC: C: 0, F :0, O: 0
OX: C: +4, F: -1, O: -2
- Answer b
-
FC: N: -1, O: 0
OX: N: +1, O: -2
- Answer c
-
FC: B: -1, F: 0
OX: B: +3, F: -1
- Answer d
-
FC: Sn: -1; Cl: 0
OX: Sn: +2, Cl: -1
- Answer e
-
FC: C: 0, H: 0
OX: C: -2, H: +1
- Answer f
-
FC: P: +1, O: -1
OX: P: +5, O: -2
PROBLEM \(\PageIndex{5}\)
Based on formal charge considerations, which of the following would likely be the correct arrangement of atoms in nitrosyl chloride: ClNO or ClON?
- Answer
-
ClNO
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PROBLEM \(\PageIndex{6}\)
Based on formal charge considerations, which of the following would likely be the correct arrangement of atoms in hypochlorous acid: HOCl or OClH?
- Answer
-
HOCl
PROBLEM \(\PageIndex{7}\)
Based on formal charge considerations, which of the following would likely be the correct arrangement of atoms in sulfur dioxide: OSO or SOO?
- Answer
-
OSO
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PROBLEM \(\PageIndex{8}\)
Draw the structure of hydroxylamine, H 3 NO, and assign formal charges; look up the structure. Is the actual structure consistent with the formal charges?
- Answer
-
The structure that gives zero formal charges is consistent with the actual structure:
PROBLEM \(\PageIndex{9}\)
Which of the following structures would we expect for nitrous acid? Determine the formal charges:
- Answer
-
The first structure is the best structure. the formal charges are closest to 0 (and also the second structure does not give a complete octet on N)
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Contributors and Attributions
-
Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at http://cnx.org/contents/85abf193-2bd...a7ac8df6@9.110 ).
- Adelaide Clark, Oregon Institute of Technology