12. Molecular Shapes & Valence Bond Theory

Hybridization

Valence Bond Theory & Hybrid Orbitals

Write a hybridization and bonding scheme for each molecule or 
ion. Sketch the structure, including overlapping orbitals, and label 
all bonds using the notation shown in Examples 10.6 and 10.7. 
d. I3-

Hybridization Example 1

The valence electron configurations of several atoms are 
shown here. How many bonds can each atom make without 
hybridization? 
b. P 3s23p3

Use the chemical structure for Tagamet, a drug used to treat 
peptic ulcers and heartburn, to answer questions 8 and 9. 
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/f6650f3a267c8960-1670532827597.jpg" alt="" />
Which orbitals overlap to form bond 2? (LO 8.5) 
(a) C (sp) with C (sp) (b) C (sp) with C 1sp22 
(c) C 1sp22 with C 1sp22 (d) C 1sp32 with C 1sp22

The valence electron configurations of several atoms are shown 
here. How many bonds can each atom make without 
hybridization? 
c. O 2s22p4

The valence electron configurations of several atoms are
shown here. How many bonds can each atom make without
hybridization?
a. Be 2s2

For each statement, indicate whether it is true or false. 
(d) Nonbonding electron pairs cannot occupy a hybrid orbital.

(c) Write the formulas for the analogous
species of the elements of period 3;

What is the hybridization of the central atom in (c) O3?

How many of the following molecules have sp3d2 hybridization on the central atom?&nbsp;SeCl6&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; XeCl4 &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; IF5&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; AsCl5

Although polyethylene can twist and turn in random ways,
the most stable form is a linear one with the carbon backbone
oriented as shown in the following figure:
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/0dfa869296767bd0-1665583251829.jpg" alt="" />
The solid wedges in the figure indicate bonds from carbon
that come out of the plane of the page; the dashed wedges
indicate bonds that lie behind the plane of the page.
(a) What is the hybridization of orbitals at each carbon 
atom? What angles do you expect between the bonds?

Consider the Lewis structure for acetic acid, which is known
as vinegar:

(b) What are the hybridizations of the
orbitals on the two oxygen atoms, and what are the approximate
bond angles at the oxygen that is connected to carbon
and hydrogen? 

What are the hybridizations of the orbitals on the two oxygen atoms?

The genetic code is based on four different bases with the structures
shown here. Assign a geometry and hybridization to each
interior atom in these four bases.
d. guanine <img src="https://lightcat-files.s3.amazonaws.com/problem_images/01927053afc69172-1660062922440.jpg" alt="" />

How many types of hybrid orbitals do we use to describe each 
molecule? 
a. N2O5

Describe the hybridization of the carbon atom in the poisonous 
gas phosgene, Cl2CO, and make a rough sketch of the 
molecule showing its hybrid orbitals and p bonds.

(c) What atomic orbitals are involved in the stacking of graphite 
sheets with each other?<img src="https://lightcat-files.s3.amazonaws.com/problem_images/9704249acc76af56-1665587873434.jpg" alt="" />

(b) What is the hybridization of the carbon atoms in each molecule?

Cyclooctatetraene dianion, C8H8 
2-, is an organic ion with the 
structure shown. Considering only the p bonds and not the 
s bonds, cyclooctatetraene dianion can be described by 
the following energy diagrams of its p molecular orbitals:
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/630f530932bc2a5c-1670652357698.jpg" alt="" />
(a) What is the hybridization of the 8 carbon atoms?

What hybridization do you expect for atoms that have the 
following numbers of charge clouds? 
(c) 4

Write orbital diagrams (boxes with arrows in them) to represent 
the electron configurations of carbon before and after sp 
hybridization.

What spatial arrangement of charge clouds corresponds to
each of the following kinds of hybridization?
(a) sp3

(a) If you combine two atomic orbitals on two different atoms
to make a new orbital, is this a hybrid orbital or a molecular
orbital?

Butadiene, C4H6, is a planar molecule that has the following
carbon–carbon bond lengths:
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/f8dfe28304ec5110-1676675272994.jpg" alt="" />
(b) From left to right, what is the hybridization of each carbon atom in butadiene?

Hybridization Concept 2

Consider the Lewis structure for acetic acid, which is known
as vinegar:
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/0ed78d13671e70b3-1661271661096.jpg" alt="" />
(a) What are the approximate bond angles about each of the 
two carbon atoms, and what are the hybridizations of the orbitals 
on each of them?

The molecule shown below is called furan. It is represented in
typical shorthand way for organic molecules, with hydrogen
atoms not shown, and each of the 4 vertices representing a
carbon atom.
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/e197b3eb4d7295b6-1661270015138.jpg" alt="" />
(e) The C¬C¬C bond angles in furan are much smaller than those
in benzene. The likely reason is which of the following: (i) The
hybridization of the carbon atoms in furan is different from
that in benzene, (ii) Furan does not have another resonance
structure equivalent to the one above, or (iii) The atoms in a
five-membered ring are forced to adopt smaller angles than in
a six-membered ring.

Consider the SCl2 molecule. (c) What hybrid orbitals 
should be constructed on the S atom to make the S-Cl bonds 
in SCl2?

Consider the molecule BF3. (c) What hybrid orbitals
should be constructed on the B atom to make the B–F bonds
in BF3?

The structure of borazine, B3N3H6, is a six-membered ring
of alternating B and N atoms. There is one H atom bonded
to each B and to each N atom. The molecule is planar.
(e) What are the hybridizations at the B and N atoms in
the Lewis structures from parts (a) and (b)? Would you expect
the molecule to be planar for both Lewis structures?

Would you expect the molecule to be planar for both Lewis structures?

Consider the SCl2 molecule.(d) What valence orbitals, if any, remain unhybridized on the S atom in SCl2?

Write a hybridization and bonding scheme for each molecule or 
ion. Sketch the structure, including overlapping orbitals, and label 
all bonds using the notation shown in Examples 10.6 and 10.7. 
a. COCl2 (carbon is the central atom)

(d) Can two s orbitals combine to form a p bond? Explain.

Benzyne, C6H4, is a highly energetic and reactive molecule. What
hybridization do you expect for the two triply bonded carbon
atoms? What are the “theoretical” values for the C¬C‚C
bond angles? Why do you suppose benzyne is so reactive?
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/2bbaa7671fdb532e-1670527116362.jpg" alt="" />

Azo dyes are organic dyes that are used for many applications,
such as the coloring of fabrics. Many azo dyes are
derivatives of the organic substance azobenzene, C12H10N2.
A closely related substance is hydrazobenzene, C12H12N2.
The Lewis structures of these two substances are
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/d1add3cc54d3883b-1661272420495.jpg" alt="" />
(Recall the shorthand notation used for benzene.)
(b) How many unhybridized atomic orbitals
are there on the N and the C atoms in each of the substances?

How many unhybridized atomic orbitals are there on the N and the C atoms in hydrazobenzene?

Consider the structure of the amino acid aspartic acid. Indicate 
the hybridization about each interior atom.

Hybridization Concept 1

Shown here are three pairs of hybrid orbitals, with each set
at a characteristic angle. For each pair, determine the type of
hybridization, if any, that could lead to hybrid orbitals at the
specified angle.
(a) <img src="https://lightcat-files.s3.amazonaws.com/problem_images/db32742b75b0e2f8-1664542822518.jpg" alt="" />
(b) <img src="" alt="" />
(c) <img src="" alt="" />

Indicate the hybridization of the central atom in (d) AlI3.

Although I3- is a known ion, F3- is not. (d) Yet another classmate says F3- does not exist because F is too small to make bonds to more than one atom. Is this classmate possibly correct?

Use the chemical structure for Tagamet, a drug used to treat
peptic ulcers and heartburn, to answer questions 8 and 9.
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/dfeab22c0073819a-1670533227398.jpg" alt="" />
Which orbitals overlap to form bond 1? (LO 8.5)
(a) s bond: N 1sp22 with C 1sp22; p bond: N (p) with C (p)
(b) N 1sp22 with C 1sp22
(c) s bond: N 1sp22 with C 1sp22; p bond: N 1sp22 with
C 1sp22
(d) s bond: N (sp) with C 1sp22; p bond: N (p) with C (p)

Many primary amines, RNH2, where R is a carboncontaining
fragment such as CH3, CH3CH2, and so on,
undergo reactions where the transition state is tetrahedral.
(a) Draw a hybrid orbital picture to visualize the
bonding at the nitrogen in a primary amine (just use a C
atom for “R”).

How many types of hybrid orbitals do we use to describe each
molecule?
b. C2H5NO (four C ¬ H bonds and one O ¬H bond)

The odor of cinnamon oil is due to cinnamaldehyde, C9H8O. 
What is the hybridization of each carbon atom in cinnamaldehyde? 
How many s and how many p bonds does cinnamaldehyde 
have?
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/7aa8fc4253e0c491-1670650409549.jpg" alt="" />

Sodium azide is a shock-sensitive compound that releases 
N2 upon physical impact. The compound is used in automobile 
airbags. The azide ion is N3-. (b) State 
the hybridization of the central N atom in the azide ion.

Orbitals: Crash Course Chemistry #25

In the cyanate ion, OCN-, carbon is the central atom.
(d) Which hybrid orbitals are used by the C atom, and how 
many p bonds does the C atom form?

Hybridization of Atomic Orbitals - Sigma & Pi Bonds - Sp Sp2 Sp3

The following molecular model is a representation of caffeine. 
Identify the position(s) of multiple bonds in caffeine, 
and tell the hybridization of each carbon atom. 1Red = O, 
blue = N, gray = C, ivory = H.2
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/60053034147ad52c-1670656941977.jpg" alt="" />

Indicate the hybridization of the central atom in (b) SeF6

Write a hybridization and bonding scheme for each molecule. 
Sketch the molecule, including overlapping orbitals, and label 
all bonds using the notation shown in Examples 10.6 and 10.7. 
a. CCl4

Draw and determine the hybridization and unhybridized orbitals for the following covalent compound.&nbsp;KrBr4&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Hybridization:&nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Unhybridized Orbitals:

Write a hybridization and bonding scheme for each molecule. 
Sketch the molecule, including overlapping orbitals, and label 
all bonds using the notation shown in Examples 10.6 and 10.7. 
b. NH3

Indicate which orbitals overlap to form the s bonds in each
compound.
a. BeBr2
b. HgCl2
c. ICN

Which hybridization scheme allows the central atom to form 
more than four bonds? 
sp3, sp3d, sp2

What is the hybridization of the central atom in (d) NO2?

Write a hybridization and bonding scheme for each molecule. 
Sketch the molecule, including overlapping orbitals, and label 
all bonds using the notation shown in Examples 10.6 and 10.7. 
c. OF2

The connections between atoms in the amino acid histidine are
shown. Complete the electron-dot structure by adding multiple
bonds and lone pairs of electrons. Give the hybridization on the
numbered carbon and nitrogen atoms. (LO 8.4)
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/b547ab12c3f9e4e1-1670534745733.jpg" alt="" />
(a) N1 = sp2, N2 = sp, C1 = sp2, C2 = sp3 
(b) N1 = sp2, N2 = sp2, C1 = sp3, C2 = sp2 
(c) N1 = sp3, N2 = sp, C1 = sp2, C2 = sp3 
(d) N1 = sp3, N2 = sp2, C1 = sp2, C2 = sp3

There are two lone pairs on the interior oxygen atom.

The polarity of the individual O&#x2212;C bonds do not cancel.

Correct, dimethyl ether does have a dipole moment.

 Determine the geometry around the interior oxygen atom using VSEPR and look at the overall effect of the individual bonds dipoles. 

Determine the geometry around the central oxygen atom and the molecular polarity of dimethyl ether: <img src="https://media.pearsoncmg.com/ph/esm/esm_tro_chemistry_6/msa/content/practice-quiz/img/tro_pq_c11q5.jpg" alt="Molecule showing, from left to right, a H sub 3 C group singly bonded to an oxygen atom with two lone pairs singly bonded to a CH sub 3 group." class="block">

Draw a picture that shows all three 2p orbitals on one atom 
and all three 2p orbitals on another atom. (b) How 
many p bonds can the two sets of 2p orbitals make with each 
other?

In the hydrocarbon
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/f86522931d9308a8-1661272986619.jpg" alt="" />
(a) What is the hybridization at each carbon atom in the
molecule?

The drawing below shows the overlap of two hybrid orbitals
to form a bond in a hydrocarbon. (b) Which of the following could be the identity of the hydrocarbon: (i) CH4, (ii) C2H6, (iii) C2H4, or (iv) C2H2?
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/9c01ac2411292437-1661273568597.jpg" alt="" />

What is the hybridization of the central atom in (a) PBr5?

Write a hybridization and bonding scheme for each molecule
that contains more than one interior atom. Indicate the hybridization
about each interior atom. Sketch the structure, including
overlapping orbitals, and label all bonds using the notation
shown in Examples 10.6 and 10.7.
c. C2H6 (skeletal structure H3CCH3)

Benzaldehyde, C7H6O, is a fragrant substance responsible for 
the aroma of almonds. Its Lewis structure is
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/2209f93e17f278e7-1676671312668.jpg" alt="" /> 
(a) What is the hybridization at each of the carbon atoms of the 
molecule?

The valence electron configurations of several atoms are 
shown here. How many bonds can each atom make without 
hybridization? 
c. F 2s22p5

Valence Bond Theory & Hybrid Atomic Orbitals

Nitrogen uses one s and three p orbitals in hybridization.

Correct, three hybridized orbitals form bonds to the hydrogen atoms and one is occupied by a lone pair.

sp3d2

 Draw the Lewis structure and then determine the number and type of atomic orbitals used by the central nitrogen atom.  Relate this to the type of hybridization. 

What is the hybridization of the nitrogen atom in ammonia?

Which of the following molecules has a central atom with 
sp3 hybridization? (LO 8.4) 
(a) PCl5 (b) OF2 
(c) CO2 (d) SF4

The orbital diagram that follows presents the final step in the
formation of hybrid orbitals by a silicon atom. (b) What type of hybrid orbital is produced in this hybridization?

Write a hybridization and bonding scheme for each molecule or 
ion. Sketch the structure, including overlapping orbitals, and label 
all bonds using the notation shown in Examples 10.6 and 10.7. 
a. SO32 -

The valence electron configurations of several atoms are shown
here. How many bonds can each atom make without
hybridization?
a. B 2s22p1

How many unhybridized orbitals does the beryllium atom possess in BeCl2?

Valence Bond Theory Explained (with examples, H2, CH4)

Which of the following statements about hybrid orbitals is 
or are true? (i) After an atom undergoes sp hybridization, 
there is one unhybridized p orbital on the atom, (ii) Under 
sp2 hybridization, the large lobes point to the vertices of an 
equilateral triangle, and (iii) The angle between the large 
lobes of sp3 hybrids is 109.5°.

The VSEPR model is a simple predictive tool that is usually,
but not always, correct. Take urea, for instance, a waste
product excreted in animal urine:
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/da05f048134a9081-1670516983584.jpg" alt="" />
What hybridization would you expect for the C and N atoms in urea according to the VSEPR model, and what approximate values would you expect for the various bond angles? What are the actual hybridizations and bond angles based on the
molecular model shown? 1Red = O, gray = C, blue = N,
ivory = H.2

Consider the structure of the amino acid alanine. Indicate the
hybridization about each interior atom.
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/bd8e2540094619fb-1660130542889.jpg" alt="" />

Aspirin has the following connections among atoms. Complete
the electron-dot structure for aspirin, tell how many s bonds
and how many p bonds the molecule contains, and tell the
hybridization of each carbon atom.
<img src="https://lightcat-files.s3.amazonaws.com/problem_images/9a5e32a003b9fb1e-1670646350177.jpg" alt="" />

What hybridization do you expect for the atom
that is underlined in each of the following species?
(a) IO2-

Which hybridization scheme allows the formation of at least 
one p bond? 
sp3, sp2, sp3d2

Valence shell atomic orbitals mix to form hybrid orbitals. For an s orbital to bond with a p orbital the central element must first undergo hybridization.

Write orbital diagrams (boxes with arrows in them) to represent 
the electron configuration of carbon before and after sp3 
hybridization.

What is the hybridization of the B and N atoms in borazine, 
what are the values of the B¬N¬B and N¬B¬N bond 
angles, and what is the overall shape of the molecule?

The equilibrium constant Kc for the gas-phase thermal decom-position of cyclopropane to propene is 1.0 * 105 at 500 K: <img src="https://lightcat-files.s3.amazonaws.com/problem_images/72f0a578e51d8bce-1671207411409.jpg" alt="" />
(e) Why is cyclopropane so reactive? (Hint: Consider the hybrid orbitals used by the C atoms.)

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1. Intro to General Chemistry

2. Atoms & Elements

3. Chemical Reactions

4. BONUS: Lab Techniques and Procedures

5. BONUS: Mathematical Operations and Functions

6. Chemical Quantities & Aqueous Reactions

7. Gases

8. Thermochemistry

9. Quantum Mechanics

10. Periodic Properties of the Elements

11. Bonding & Molecular Structure

13. Liquids, Solids & Intermolecular Forces

14. Solutions

15. Chemical Kinetics

16. Chemical Equilibrium

17. Acid and Base Equilibrium

18. Aqueous Equilibrium

19. Chemical Thermodynamics

20. Electrochemistry

21. Nuclear Chemistry

22. Organic Chemistry

23. Chemistry of the Nonmetals

24. Transition Metals and Coordination Compounds

[BOOK CHEM] Clutch Version

MO Theory: Homonuclear Diatomic Molecules

Homonuclear Diatomic Molecules are composed of 2 identical elements bonded together.

Equatorial and Axial Positions

Covalent compounds with 5 or 6&nbsp;electron groups have equatorial and axial positions for surrounding elements

MO Theory: Heteronuclear Diatomic Molecules

Heteronuclear Diatomic Molecules are composed of 2 different elements bonded together.

Bond Angles

Bond Angles&nbsp;result from surrounding elements and lone pairs around the central element positioning themselves at an optimal distance.&nbsp;

Molecular Orbital Theory

Molecular Orbital Theory&nbsp;allows us to predict the distribution of electrons within a molecule.&nbsp;

MO Theory: Bond Order

Molecular Orbital Diagrams can be used to determine the bond order of a molecule.

Electron Geometry

The simplest system for geometrical shapes that focuses on the number of electron groups around the central atom.

How would an&nbsp;s orbital combine with a p orbital to form a covalent bond? The answer is through hybridization where a hybrid&nbsp;oribital is formed.&nbsp;

Molecular Geometry

True Shape of Molecules that takes into account differences&nbsp;in repulsion between lone pairs and surrounding elements.