3.3.3.0: Formal Charge and Oxidation State (Problems)
- Page ID
- 210707
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)PROBLEM \(\PageIndex{1}\)
Determine the formal charge and oxidation state of each element in the following:
a. HCl
b. CF4
c. PCl3
- 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. H3O+
b. \(\ce{SO4^2-}\)
c. NH3
d. \(\ce{O2^2-}\)
e. H2O2
- 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
- Click here to see a video of the solution
PROBLEM \(\PageIndex{3}\)
Calculate the formal charge and oxidation state of chlorine in the molecules Cl2 and CCl4.
- Answer
-
FC: Cl in Cl2: 0; Cl in CCl4: 0
OX: Cl in Cl2: 0; Cl in CCl4: -1
PROBLEM \(\PageIndex{4}\)
Calculate the formal charge and oxidation state of each element in the following compounds and ions:
a. F2CO
b. NO–
c. \(\ce{BF4-}\)
d. \(\ce{SnCl3-}\)
e. H2CCH2
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
- Click here to see a video of the solution
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
- Click here to see a video of the solution
PROBLEM \(\PageIndex{8}\)
Draw the structure of hydroxylamine, H3NO, 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
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