Question 1

Of the molecules below,only ________ is nonpolar. A)BF₃ B)NF₃ C)IF₃ D)PBr₃ E)BrCl₃

Accepted Answer

BF3 (Boron trifluoride) is nonpolar because it has a trigonal planar geometry, which allows for the dipole moments to cancel out, resulting in a molecule with no net dipole moment.

Question 2

The electron-domain geometry and the molecular geometry of a molecule of the general formula AB_n will always be the same if ________. A)there are no lone pairs on the central atom B)there is more than one central atom C)n is greater than four D)n is less than four E)the octet rule is obeyed

Accepted Answer

The electron-domain geometry and the molecular geometry in a molecule of the general formula AB_n will always be the same if there are no lone pairs on the central atom. This is because the presence of lone pairs can affect the geometry of a molecule, but if there are no lone pairs, then the electron-domain geometry and the molecular geometry will be the same. The other answer choices are not applicable to this general formula and do not affect the relationship between the electron-domain geometry and the molecular geometry.

Question 3

An electron domain consists of ________. 
a.a nonbonding pair of electrons
b.a single bond
c.a multiple bond
A)a only
B)b only
C)c only
D)a, b, and c
E)b and c

Accepted Answer

An electron domain can be any region in a molecule where electrons are concentrated, such as a nonbonding pair of electrons (lone pairs), a single bond, or a multiple bond (double or triple bonds). Each of these counts as one electron domain in the context of VSEPR theory, which is used to predict molecular shapes.

Question 4

For molecules of the general formula AB_n,n can be greater than four ________. A)for any element A B)only when A is an element from the third period or below the third period C)only when A is boron or beryllium D)only when A is carbon E)only when A is Xe

Accepted Answer

The general formula AB_n,n represents a molecule with one atom of element A, one atom of element B (which can be repeated n times), one atom of sulfur, and one atom of an unspecified element represented by U. The maximum number of bonds an atom can form is determined by its electron configuration and its position in the periodic table. Atoms from the third period or below can have more than four bonds because they have d orbitals available for bonding, which allows them to form additional bonds. Therefore, choice B is the best answer as it correctly identifies the conditions under which n can be greater than four.

Question 5

The molecular geometry of the BrO₃^- ion is ________. A)trigonal pyramidal B)trigonal planar C)bent D)tetrahedral E)T-shaped

Accepted Answer

The BrO3- ion has a trigonal pyramidal shape due to the presence of three oxygen atoms bonded to bromine and one lone pair on the bromine, which affects the molecular geometry.

Question 6

For which of the molecules is the molecular geometry (shape)the same as the VSEPR electron domain arrangement (electron domain geometry)?
A)(i)and (ii)
B)(i)and (iii)
C)(ii)and (v)
D)(iv)and (v)
E)(v)only

Accepted Answer

The answer of For which of the molecules is the...

Question 7

The bond angles marked a,b,and c in the molecule below are about ________,________,and ________,respectively. 
A)109.5°, 109.5°, 109.5°
B)120°, 109.5°, 120°
C)109.5°, 109.5°, 120°
D)90°, 180°, 90°
E)109.5°, 109.5°, 90°

Accepted Answer

The molecule shown is trigonal bipyramidal. The angles between the axial atoms and the central atom (marked a) are 90°, while the angles between the equatorial atoms and the central atom (marked b) are 120°. The angles between the two sets of equatorial atoms (marked c) are also 120°. Therefore, the best choice is option C, which lists these angles correctly.

Question 8

The central Xe atom in the XeF₄ molecule has ________ unbonded electron pair(s)and ________ bonded electron pair(s)in its valence shell. A)1, 4 B)2, 4 C)4, 0 D)4, 1 E)4, 2

Accepted Answer

The central Xe atom in XeF4 has 2 unbonded electron pairs and 4 bonded electron pairs. XeF4 has a square planar geometry, which results from the octahedral arrangement of electron pairs around the xenon atom, with two lone pairs and four bonding pairs.

Question 9

What is the molecular shape of H₂O? A)T-shaped B)tetrahedral C)linear D)trigonal pyramidal E)bent

Accepted Answer

According to the molecular formula, there are two central atoms involved, and each one has one lone pair of electrons. Moreover, the two central atoms are connected through a single bond. This information suggests that the shape of the molecule is bent or V-shaped, with the two bonding atoms at an angle less than 180 degrees. Therefore, the best choice is E) bent.

Question 10

The basis of the VSEPR model of molecular bonding is ________.
A)regions of electron density on an atom will organize themselves so as to maximize s-character
B)regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap
C)atomic orbitals of the bonding atoms must overlap for a bond to form
D)electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions
E)hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry

Accepted Answer

The VSEPR (Valence Shell Electron Pair Repulsion) model is based on the idea that electron domains (regions of electron density) in the valence shell of an atom will arrange themselves around the central atom so as to minimize repulsions between them. This leads to the formation of specific molecular geometries depending on the number and arrangement of electron domains around the central atom. Option D correctly describes this fundamental idea of the VSEPR model.

Question 11

Of the following species,________ will have bond angles of 120°. A)PH₃ B)ClF₃ C)NCl₃ D)BCl₃ E)All of these will have bond angles of 120°.

Accepted Answer

The only species with a trigonal planar geometry, which has bond angles of 120°, is BCl₃. The other options do not have a trigonal planar geometry and therefore do not have bond angles of 120°.

Question 12

The molecular geometry consists of ________.
a.a nonbonding pair of electrons
b.a single bond
c.a multiple bond
A)a only
B)b only
C)c only
D)a, b, and c
E)b and c

Accepted Answer

The answer of The molecular geometry consists of ________.
a.a nonbonding...

Question 13

The electron-domain geometry and the molecular geometry of a molecule of the general formula AB_n are ________. A)never the same B)always the same C)sometimes the same D)not related E)mirror images of one another

Accepted Answer

The electron-domain geometry and molecular geometry depend on the number of bonded and non-bonded electron pairs. In the case of a molecule with the general formula AB_n, the arrangement of electron pairs around the central atom(s) will depend on the specific atoms present and the number of lone pairs and bonded pairs. Therefore, it is possible for the electron-domain geometry and molecular geometry to be the same or different depending on these factors, making answer choice C the best choice.

Question 14

The molecular geometry of the right-most carbon in the molecule below is ________. 
A)trigonal planar
B)trigonal bipyramidal
C)tetrahedral
D)octahedral
E)T-shaped

Accepted Answer

The answer of The molecular geometry of the right-most carbon...

Question 15

The electron-domain geometry of ________ is tetrahedral. A)CBr₄ B)PH₃ C)CCl₂Br₂ D)XeF₄ E)all of the above except XeF₄

Accepted Answer

The electron-domain geometry considers both bonding and nonbonding electron pairs. Tetrahedral geometry occurs when there are four electron domains around the central atom. A) CBr4, B) PH3, and C) CCl2Br2 all have four electron domains (single bonds) around the central atom, making their electron-domain geometry tetrahedral. D) XeF4 has six electron domains (four bonding pairs and two lone pairs), leading to an octahedral electron-domain geometry, not tetrahedral.

Question 16

Of the molecules below,only ________ is polar. A)CCl₄ B)CH₄ C)SeF₄ D)SiCl₄

Accepted Answer

To determine if a molecule is polar or not, we need to consider the electronegativities and molecular geometry. If the electronegativities are different and the molecular geometry is asymmetrical, the molecule is polar. In the given molecules, only SeF4 has different electronegativities and an asymmetrical shape, and therefore it is polar. The other molecules either have symmetrical shapes or have the same electronegativities between all atoms involved, resulting in a nonpolar molecule.

Question 17

The bond angles marked a,b,and c in the molecule below are about ________,________,and ________,respectively. 
A)90°, 90°, 90°
B)120°, 120°, 90°
C)120°, 120°, 109.5°
D)109.5°, 120°, 109.5°
E)109.5°, 90°, 120°

Accepted Answer

From the given molecule, it is clear that the central atom (carbon) is bonded to three other atoms (two hydrogens and one chlorine).
The central carbon atom has four electron domains (two single bonds and one double bond). Therefore, it has a tetrahedral electron geometry. 
Since there are no lone pairs on the central atom, the bond angles will be equal to the angles between the bonds. 
The H-C-H bond angles will be 109.5° due to the tetrahedral electron geometry. 
The Cl-C-H angles will be 109.5° as well since the two hydrogen atoms and the chlorine atom are all in the same plane. 
The Cl-C-C bond angle will be 120° since the double bond and two single bonds are collectively part of a planar geometry. 
Therefore, the correct answer is D)109.5°, 120°, 109.5°.

Question 18

PCl₅ has ________ electron domains and a ________ molecular arrangement. A)6, trigonal bipyramidal B)6, tetrahedral C)5, square pyramidal D)5, trigonal bipyramidal E)6, seesaw

Accepted Answer

PCl₅ has 5 electron domains (1 from P, 1 from S, and 3 from the 3 Cl atoms) and a trigonal bipyramidal molecular arrangement.

Question 19

In counting the electron domains around the central atom in VSEPR theory,a ________ is not included.
A)nonbonding pair of electrons
B)single covalent bond
C)core level electron pair
D)double covalent bond
E)triple covalent bond

Accepted Answer

In VSEPR theory, core level electron pairs (those in inner shells) are not considered when counting electron domains around the central atom. Only valence electrons involved in bonding or as nonbonding (lone) pairs are included.

Question 20

The molecular geometry of the left-most carbon atom in the molecule below is ________. 
A)trigonal planar
B)trigonal bipyramidal
C)tetrahedral
D)octahedral
E)T-shaped

Accepted Answer

The left-most carbon atom in the molecule has three bonded atoms and no lone pairs, indicating a tetrahedral geometry.

Quiz 9: Molecular Geometry and Bonding Theories

Of the molecules below,only ________ is nonpolar.

The electron-domain geometry and the molecular geometry of a molecule of the general formula AB_n will always be the same if ________.

An electron domain consists of ________. a.a nonbonding pair of electrons b.a single bond c.a multiple bond

For molecules of the general formula AB_n,n can be greater than four ________.

The molecular geometry of the BrO₃^- ion is ________.

For which of the molecules is the molecular geometry (shape) the same as the VSEPR electron domain arrangement (electron domain geometry) ?

The bond angles marked a,b,and c in the molecule below are about ,,and ,respectively.

The central Xe atom in the XeF₄ molecule has unbonded electron pair(s) and bonded electron pair(s) in its valence shell.

What is the molecular shape of H₂O?

The basis of the VSEPR model of molecular bonding is ________.

Of the following species,________ will have bond angles of 120°.

The molecular geometry consists of ________. a.a nonbonding pair of electrons b.a single bond c.a multiple bond

The electron-domain geometry and the molecular geometry of a molecule of the general formula AB_n are ________.

The molecular geometry of the right-most carbon in the molecule below is ________.

The electron-domain geometry of ________ is tetrahedral.

Of the molecules below,only ________ is polar.

The bond angles marked a,b,and c in the molecule below are about ,,and ,respectively.

PCl₅ has electron domains and a molecular arrangement.

In counting the electron domains around the central atom in VSEPR theory,a ________ is not included.

The molecular geometry of the left-most carbon atom in the molecule below is ________.

Quiz 9: Molecular Geometry and Bonding Theories

Of the molecules below,only ________ is nonpolar.

The electron-domain geometry and the molecular geometry of a molecule of the general formula ABn will always be the same if ________.

An electron domain consists of ________. a.a nonbonding pair of electrons b.a single bond c.a multiple bond

For molecules of the general formula ABn,n can be greater than four ________.

The molecular geometry of the BrO3- ion is ________.

For which of the molecules is the molecular geometry (shape) the same as the VSEPR electron domain arrangement (electron domain geometry) ?

The bond angles marked a,b,and c in the molecule below are about ________,________,and ________,respectively.

The central Xe atom in the XeF4 molecule has ________ unbonded electron pair(s) and ________ bonded electron pair(s) in its valence shell.

What is the molecular shape of H2O?

The basis of the VSEPR model of molecular bonding is ________.

Of the following species,________ will have bond angles of 120°.

The molecular geometry consists of ________. a.a nonbonding pair of electrons b.a single bond c.a multiple bond

The electron-domain geometry and the molecular geometry of a molecule of the general formula ABn are ________.

The molecular geometry of the right-most carbon in the molecule below is ________.

The electron-domain geometry of ________ is tetrahedral.

Of the molecules below,only ________ is polar.

The bond angles marked a,b,and c in the molecule below are about ________,________,and ________,respectively.

PCl5 has ________ electron domains and a ________ molecular arrangement.

In counting the electron domains around the central atom in VSEPR theory,a ________ is not included.

The molecular geometry of the left-most carbon atom in the molecule below is ________.

The electron-domain geometry and the molecular geometry of a molecule of the general formula AB_n will always be the same if ________.

For molecules of the general formula AB_n,n can be greater than four ________.

The molecular geometry of the BrO₃^- ion is ________.

The bond angles marked a,b,and c in the molecule below are about ,,and ,respectively.

The central Xe atom in the XeF₄ molecule has unbonded electron pair(s) and bonded electron pair(s) in its valence shell.

What is the molecular shape of H₂O?

The electron-domain geometry and the molecular geometry of a molecule of the general formula AB_n are ________.

The bond angles marked a,b,and c in the molecule below are about ,,and ,respectively.

PCl₅ has electron domains and a molecular arrangement.