Chemistry Chapter 9

How many molecular geometries are possible for a molecule where the central atom is surrounded by four electron domains?

3

What is the minimum number of terminal atoms that must be bonded to a central atom in order for a molecule to necessarily have a three dimensional shape? Assume the number of electron domains around the central atom is restricted to 6.

5

Orbital hybridization for a linear shape?

Sp and Sp³d

Orbital hybridization for a trigonal planar shape?

Sp²

Orbital hybridization for a bent shape?

Sp², Sp³

Orbital hybridization for a tetrahedral shape?

Sp³

Orbital hybridization for a trigonal pyramidal shape?

Sp³

Orbital hybridization for a T shaped shape?

Sp³d

Orbital hybridization for a see saw shape?

Sp³d

Orbital hybridization for a trigonal bipyramidal shape?

Sp³d

Orbital hybridization for a octahedral shape?

Sp³d²

Orbital hybridization for a square planar shape?

Sp³d²

Orbital hybridization for a square pyramidal shape?

Sp³d²

VSPER

Valence Shell Electron Pair Repulsion; the shape of a molecule is related to the number of electron domains in the valence shell of the central atom

In dinitrogen monoxide (nitrous oxide, laughing gas) one of the nitrogens is the central atom, with the other N and O being terminal atoms. What is the electron-domain geometry about the central atom of N₂O? a. linear b. trigonal planar c. tetrahedral d. trigonal pyramidal e. octahedral

a

Tetrahedron

a 3D polyhedron composed of four triangular faces meeting at four vertices

Two electron domains about an atom result in?

a linear electron domain geometry

What do we learn from lewis structures?

atom connections, number of bonds, types of bonds, nonbonding electrons,

What is the molecular geometry in the phosphite ion, PO₃³⁻? a. trigonal planar b. trigonal pyramidal c. T shaped d. tetrahedral e. see saw

b

Which of the following molecules is/are polar? Select all the polar molecules, this is a multiple response question. a. SiCl₄ b. SCl₄ c. ClF₄⁻ d. PO₄³⁻ e. TeF₄

b. and e.

Which of the following are essential tenets of valence shell electron pair repulsion (VSEPR) theory? Select all of the correct answers, this is a multiple response question. a. atoms in molecules are restricted to 4 bonds, or 8 total electrons around each atom. b. Electron domains are oriented in space such that interactions with other electron domain are minimized c. double and triple bonds count as a single electron domain for the purpose of predicting electron pair geometry d. Electron domains are oriented in space such that interactions with other electron domain are maximized e. nonbonded (lone) electron pairs require more space than bonded electron pairs. f. nonbonded (lone) electron pairs require less space than bonded electron pairs. g. a double bond counts as two electron domains in VSEPR h. a chemical bond where there are six bonding electrons between the two bonded atoms counts as three electron domains

b., c., and e.

What is the electron-domain geometry about the central atom (Te) of TeF₄? a. trigonal planar b. tetrahedral c. trigonal pyramidal d. trigonal bipyramidal e. octahedral

d

Propyne has the "condensed structural formula" CHCCH₃. Note that in this condensed structure, the hydrogens are bonded as terminal atoms to the carbons atom in front of them, while all the carbon atoms are connected to one another in the order shown. Draw the Lewis structure for propyne. In this structure, there are ___(i)_____ C-C sigma bonds and ____(ii)_____ C-C pi bonds. a. (i) 1; (ii) 1 b. (i) 3; (ii) 1 c. (i) 2; (ii) 1 d. (i) 1; (ii) 2 e. (i) 2; (ii) 2

e

The molecular geometry of IF5 is ____(i)______ and the molecular geometry of PCl5 is _______(ii)______. a. (i) trigonal bipyramidal; (ii) octahedral b. (i) trigonal bipyramidal; (ii) trigonal bipyramidal c. (i) square pyramidal; (ii) square pyramidal d. (i) Trigonal bipyramidal; (ii) square pyramidal e. (i) square pyramidal; (ii) trigonal bipyramidal

e

What is the molecular geometry in SF₄? a. trigonal planar b. trigonal pyramidal c. T shaped d. tetrahedral e. see saw

e

For carbon dioxide, the hybridization on C is ____(i)_______ and the hybridization on O is _____(ii)________.

i- sp; ii- sp²

Propylene has the "condensed structural formula" CH₂CHCH₃. Note that in this condensed structure, the hydrogens are bonded as terminal atoms to the carbons atom in front of them, while all the carbon atoms are connected to one another in the order shown. Draw the Lewis structure for propylene. In this structure, the hybridization of the leftmost C is ___(i)_____ the hybridization of the central atom is _____(ii)_____, and the hybridization of the right most atom is ____(iii)______.

i- sp²; ii- sp²; iii- sp³

What are the orbital hybridizations on bromine in the following compounds: (i) BrO₃⁻ (ii) BrCl₃?

i- sp³; ii- sp³d

Six electron domains attached to a central atom is _________ geometry

octahedral

Bond angles

the angles made by lines joining nuclei of atoms in a molecule, three atoms are required to define a bond angle

How many molecular geometries are possible for a molecule where the central atom is surrounded by two electron domains?

1

How many molecular geometries are possible for a molecule where the central atom is surrounded by three electron domains?

2

How many molecular geometries are possible for a molecule where the central atom is surrounded by six electron domains?

3

How many molecular geometries are possible for a molecule where the central atom is surrounded by five electron domains?

4

Draw the best Lewis structure for the cyanate anion (CNO⁻) based on formal charge considerations. Note that C is the central atom. In this structure there are: a. two sigma bonds and two pi bonds b. three sigma bonds and no pi bonds c. three sigma bonds and one pi bond d. three sigma bonds and two pi bonds e. two sigma bonds and three pi bonds

a

What is the molecular geometry in the nitrate ion, NO₃⁻? a. trigonal planar b. trigonal pyramidal c. T shaped d. tetrahedral e. see saw

a

Which of the following molecules is/are polar? Select all the polar molecules, this is a multiple response question. a. PH₃ b. SO₃ c. ClF₃ d. NO₃⁻ e. AsF₃

a., c. and e.

Which of the following is counted as a single "electron domain" when applying VSEPR theory? Select all the correct answers, this is a multiple response question. a. a lone pair of electrons in a valence shell b. a lone pair of electrons in a core shell c. a chemical bond where there are four bonding electrons between the two bonded atoms d. a triple bond e. a double bond

a., c., d., and e.

Draw a Lewis structure for N₂. Then answer the following: the bonding in N₂ is best described by how many TOTAL bonds, and of which types: a. three sigma bonds b. one sigma bond and two pi bonds c. three pi bonds d. two sigma bonds and one pi bond e. one sigma bond and one pi bond

b

What is the electron-domain geometry about the central atom (S) of SO₂? a. linear b. trigonal planar c. tetrahedral d. trigonal pyramidal e. trigonal bipyramidal

b

What is the electron-domain geometry about the central atom (S) of SO₃? a. linear b. trigonal planar c. tetrahedral d. trigonal pyramidal e. trigonal bipyramidal

b

Which of the following molecules is/are polar? Select all the polar molecules, this is a multiple response question. a. CO₂ b. SO₂ c. OF₂ d. ICl₂⁻ e. NO₂

b., c., and e.

Sigma bonds

bonding electrons are centered on the internuclear axis, the line connecting the two nuclei of the bonded atoms

pi bonds

bonding electrons are in nonhybridization p orbitals perpendicular to the internuclear axis

Draw a Lewis structure for formaldehyde, CH₂O, in which C is the central atom. Then answer the following: the bonding in formaldehyde is best described by how many TOTAL bonds, and of which types: a. three sigma bonds b. two sigma bond and two pi bonds c. three sigma bonds and one pi bond d. two sigma bonds and one pi bond e. two sigma bonds and two pi bonds only

c

For the phosphate ion drawn in the form where the central P atom bears a formal charge of 0, there are: a. four sigma bonds and two pi bonds b. four sigma bonds and no pi bonds c. four sigma bonds and one pi bond d. three sigma bonds and two pi bonds e. three sigma bonds and one pi bond

c

What is the electron-domain geometry about the central atom (Cl) of ClO₂⁻? a. linear b. trigonal planar c. tetrahedral d. trigonal pyramidal e. octahedral

c

What is the molecular geometry in ClF₃? a. trigonal planar b. trigonal pyramidal c. T shaped d. tetrahedral e. see saw

c

Which electron domain geometry is associated with the largest number of molecular geometries? a. trigonal planar b. tetrahedral c. trigonal bipyramidal d. octahedral e. more than one of the above

c

For XeF₂, the electron domain geometry is _______(i)________ and the molecular geometry is ______(ii)________. a. (i) linear; (ii) linear b. (i) tetrahedral (ii) bent c. (i) trigonal planar (ii) bent d. (i) trigonal bipyramidal (ii) bent e. (i) trigonal bipyramidal (ii) linear

e

What is the electron-domain geometry about the central atom (Br) of BrF₅? a. trigonal planar b. tetrahedral c. trigonal pyramidal d. trigonal bipyramidal e. octahedral

e

What is the electron-domain geometry about the central atom (Xe) of XeF₄? a. trigonal planar b. tetrahedral c. trigonal pyramidal d. trigonal bipyramidal e. octahedral

e

Molecular geometry

the arrangement of bonded atoms in space about a central atom

Electron domain geometry

the arrangement of electron domains in space about a central atom

Tetrahedral electron domain geometry

the central atom is at the center of a tetrahedron and the electron pairs are pointing towards the four vertices