chem exam 3 - ch 7 Copied from somone els
According to VSEPR theory, a molecule with the general formula AX2E2 will have a _____ molecular shape.
bent
What is the molecular shape of HOF as predicted by the VSEPR theory?
bent
What is the molecular shape of NO2- as predicted by the VSEPR theory?
bent
What is the molecular shape of NOCl as predicted by the VSEPR theory?
bent
Predict the molecular geometry and polarity of the SO2 molecule.
bent, polar
What is the molecular shape of the H2O molecule?
bent.
Which of the following atoms, in the ground state, has unpaired electrons?
c
A molecule which contains polar bonds will always have a dipole moment.
false
According to VSEPR theory, a molecule with the general formula AX3E2 (where E represents a lone pair on A) will be trigonal planar.
false
According to molecular orbital theory, all diatomic molecules with an even number of electrons will be diamagnetic.
false
The angles between sp2 hybrid orbitals are 109.5°.
false
The bond angle for a sp hybrid orbital is smaller than the bond angle for a sp2 hybrid orbital.
false
Predict the actual bond angles in BrF3 using the VSEPR theory.
less than 90°
What is the molecular shape of BeH2 as predicted by the VSEPR theory?
linear
What is the molecular shape of ClF2- as predicted by the VSEPR theory?
linear
What is the molecular shape of N2O as predicted by the VSEPR theory?
linear
What is the molecular shape of the thiocyanate anion, SCN-, as predicted by the VSEPR theory? (Carbon is the central atom.)
linear
Predict the geometry and polarity of the CS2 molecule.
linear, nonpolar
According to the VSEPR theory, will the molecule PF5 be polar or nonpolar?
non polar
What is the molecular shape of SiF6^2- as predicted by the VSEPR theory?
octahedral
How many pi-bonds in CH3COCH3?
one
According to valence bond theory, the triple bond in ethyne (acetylene, C2H2) consists of
one sigma bond and two pi bonds.
___________ _________ results from parallel overlap of two p orbitals
pi bonds
Complete this sentence: The PCl5 molecule has
polar bonds, but is a nonpolar molecule.
What is the molecular shape of XeO2F2 as predicted by the VSEPR theory?
see-saw
Carbon uses ______ hybrid orbitals in ClCN.
sp
The hybridization of the central nitrogen atom in the molecule N2O is
sp
A molecule with the formula AX2 uses _________ to form its bonds.
sp hybrid orbitals
Valence bond theory predicts that carbon will use _____ hybrid orbitals in the carbonate anion, CO3^2-.
sp2
Valence bond theory predicts that sulfur will use _____ hybrid orbitals in sulfur dioxide, SO2.
sp2
What is the hybridization on the central atom in NO3-?
sp2
Determine the shape (geometry) of PCl3 and then decide on the appropriate hybridization of phosphorus in this molecule. (Phosphorus is the central atom.)
sp3
Indicate the type of hybrid orbitals used by the central atom in PCl3.
sp3
What is the hybridization of the central atom in ClO3-?
sp3
When PCl5 solidifies it forms PCl4+ cations and PCl6- anions. According to valence bond theory, what hybrid orbitals are used by phosphorus in the PCl4+ cations?
sp3
A molecule with the formula AX4 uses _________ to form its bonds.
sp3 hybrid orbitals
The N - N - H bond angles in hydrazine N2H4 are 112°. What is the hybridization of the nitrogen orbitals predicted by valence bond theory?
sp3.
Indicate the type of hybrid orbitals used by the central atom in CCl4.
sp3d
Valence bond theory predicts that iodine will use _____ hybrid orbitals in ICl2-.
sp3d
What is the hybridization of As in the AsF4- ion?
sp3d
What is the hybridization of the As atom in the AsF5 molecule?
sp3d
Indicate the type of hybrid orbitals used by the central atom in SF6.
sp3d2
A molecule with the formula AX4E2 uses _________ to form its bonds.
sp3d2 hybrid orbitals
According to VSEPR theory, a molecule with the general formula AX4E2 will have a _____ molecular shape.
square planar.
According to VSEPR theory, a molecule with the general formula AX5E will have a ______ molecular shape.
square pyramidal
According to the VSEPR theory, the molecular shape of SiCl4 is
tetrahedral
What is the molecular shape of ClO3F as predicted by the VSEPR theory?
tetrahedral
What is the molecular shape of the CH4 molecule?
tetrahedral
___________ is the electron-domain geometry and _________ is the molecular shape for ammonia.
tetrahedral and pyramidal
Predict the geometry around the central atom in PO4^3-.
tetrahedral.
According to VSEPR theory, a molecule with the general formula AX5Eo will have a ______ molecular shape.
trigonal bipyramidal
Use VSEPR theory to predict the electron group arrangement around iodine, the central atom in the ion IF2-.
trigonal bipyramidal
Use VSEPR theory to predict the molecular geometry of CO3^2-
trigonal planar
According to VSEPR theory, a molecule with the general formula AX3Eo will have a ______ molecular shape.
trigonal planar.
According to the VSEPR theory, the molecular shape of the carbonate ion, CO32 -, is
trigonal planar.
According to the VSEPR theory, the shape of the SO3 molecule is
trigonal planar.
According to the VSEPR theory, the molecular shape of ammonia is
trigonal pyramidal
Use VSEPR theory to predict the molecular geometry of H3O+ (hydronium ion).
trigonal pyramidal
Use VSEPR theory to predict the shape of the PCl3 molecule.
trigonal pyramidal
Predict the geometry around the central atom in SO3^2-.
trigonal pyramidal.
Atoms of period 3 and beyond can undergo sp3d 2 hybridization, but atoms of period 2 cannot
true
In the valence bond treatment, a pi bond is formed when two 2p orbitals overlap side to side
true
In the valence bond treatment, overlap of an s orbital on one atom with an sp3 orbital on another atom can give rise to a sigma bond.
true
Pi bonds are covalent bonds in which the electron density is concentrated above and below the plane of the nuclei of the bonding atoms.
true
The BrF5 molecule has polar bonds and has a net dipole moment.
true
The number of lone pairs of electrons on the central atoms is the main factor that is used to determine the molecular shape or molecular geometry.
true
To correctly determine the molecular shape of a molecule requires that you first draw the Lewis structure for the molecule.
true
To make a sp3 hybrid orbital, one s orbital is mixed with 3 p orbitals.
true
Water has ___________ number of lone pairs of electrons on the central oxygen.
two
What is the dipole moment for CO2?
0
What is the number of lone electron pairs on the central atom of a molecule having a linear molecular geometry such as CO2?
0
How many bonds should a fluorine atom form?
1
What is the number of lone electron pairs on the central atom of a molecule having a molecular geometry of seesaw-shaped such as SF4?
1
What is the number of lone electron pairs on the central atom of a molecule having a trigonal pyramidal molecular geometry such as NH3?
1
What is the approximate bond angle for H2O?
105°
What is the approximate bond angle for NH3?
107°
What is the approximate bond angle for CCl4?
109.5°
What is the approximate bond angle for CH4?
109.5°
Predict the ideal bond angles in AsCl3 using the molecular shape given by the VSEPR theory.
109°
The bond angle for the carbonate ion is ___________.
120 degrees
What is the approximate bond angle for CO2?
180°
How many bonds should an oxygen atom form?
2
The number of pi bonds in the oxalate ion (C2O4^2-) is
2
According to molecular orbital theory, what is the bond order in the O2+ ion?
2.5
How many electron domains are on the central atom for a sp2 hybridized atom?
3
What is the number of lone electron pairs on the central atom of a molecule having a linear molecular geometry such as ClF2-?
3
How many bonds should a carbon atom form?
4
What is the total number of electron domains for a molecule having a trigonal pyramidal molecular geometry such as NH3?
4
How many electron domains are on the central atom for a sp3d hybridized atom?
5
What is the total number of electron domains for a molecule having a T-shaped pyramidal molecular geometry such as BrF3?
5
What is the total number of electron domains for a molecule having a square planar molecular geometry such as XeBr4?
6
What is the total number of electron domains for a molecule having a square pyramidal molecular geometry such as ClF5?
6
According to molecular orbital (MO) theory, the twelve outermost electrons in the O2 molecule are distributed as follows:
8 in bonding MOs, 4 in antibonding MOs.
The F - S - F bond angles in SF6 are
90° and 180°
In one sentence state the basic principle of valence bond theory.
A covalent bond forms when the orbitals of two atoms overlap and a pair of electrons occupies the region between the nuclei.
Which one of the following molecules is nonpolar?
BeCl2
For which one of the following molecules is the indicated type of hybridization not appropriate for the central atom?
BeCl2 sp2
Which one of the following molecules is polar?
BrF5
Which one of the following molecules has tetrahedral geometry?
CF4
Which one of the following molecules is polar??
CHBr3
Which one of the following molecules is nonpolar??
CO2
Consider the species Cl2+, Cl2, and Cl2-. Which of these species will be paramagnetic?
Cl2+ and Cl2-
How do you describe the molecular geometry of a molecule that does not have a central atom?
Describe the molecular geometry around all non-hydrogen atoms.
The total number of electron domains is used to determine the ___________.
Electron-Domain Geometry
Which of the following is not true of molecular orbitals?
For any substance, the number of electrons in molecular orbitals is equal to the sum of all the valence electrons on the bonding atoms.
According to the VSEPR theory, which one of the following species should be linear?
HCN
Which of the following is required for determination of the VSEPR model and the molecular shape?
Lewis structure
The number of lone pairs on the central atoms is used to determine the ____________.
Molecular Geometry
Consider the species N2-, N2, and N2+. Which of these species will be paramagnetic?
N2+ and N2-
The nitrosonium ion, NO+, forms a number of interesting complexes with nickel, cobalt, and iron. According to molecular orbital theory, which of the following statements about NO+ is correct?
NO+ has a bond order of 3 and is diamagnetic.
Which of the following atoms, in the ground state, does not have unpaired electrons?
Ne
What name is given to the shape of a molecule with no lone pairs of electrons on the central atom and 6 electron domains on the central atom?
Octahedral
Use VSEPR theory to decide which one of the following molecules and ions will definitely have at least one 90° bond angle in it. (In each case except water, the central atom is the first one in the formula.)
PCl5
According to VSEPR theory, which one of the following molecules should have a shape that is trigonal bipyramidal?
PF5
Which of the following molecules has a net dipole moment?
SF2
In which one of the following molecules is the central atom sp2 hybridized?
SO2
Which one of the following molecules has a zero dipole moment?
SO3
What is the molecular shape of the IBr3 molecule?
T-shaped
Which of the following has no net dipole moment?
TeO3
Which one of the following statements about orbital hybridization is incorrect?
The nitrogen atom in NH3 is sp2 hybridized.
What does VSEPR model mean?
Valence Shell Electron-Pair Repulsion
The electrons in the delocalized molecular orbitals of benzene (C6H6)
are free to move around the six-membered ring.
