2022 Floral Questions
The electron-dot structure (Lewis Structure) for which of the following molecules would have two unshared pairs of electrons on the central atom?
H2S
According to the VESPR model, the prgressive decrease in the bond angles is the series of molecules CH4, NH3, and H2O is best accounted for by the:
Increasing number of unshared pairs of electrons
The Lattice energy of salt is related to the energy required to separate the ions. For which of the following pairs of ions is the energy that is required to separate the ions the largest? (Assume that the distance between the ions in each pair is equal to the sum of te ionic radii.)
Mg2+ (g) and O2- (g)
Which of the following molecules has an angular (bent) geometry that is commonly represented as a resonance hybrid of two or more electron-dot structures?
O3
Which of the following can be inferred from the diagram above that shows the dependance of potantial energy on the internuclear distance between two atoms?
The atoms form a bond with a bond length of 75 pm.
In the reaction represented above, what is the hybridization of the C atoms before and after the reaction occurs?
Before: sp^2 After: sp^3
Which of the following Lewis electron-dot diagrams represents the molecule that is th most polar?
Bf-F
Which of the following molecules contains exactly thre sigma bonds and two pi bonds?
C2H2
Which of the molecules represented below contains caron with sp^2 ybridization?
C2H2Cl2
Which of the following molecules contains only single bonds?
C2H6
Which of the following molecules contains polar covalent bonds but is a nonpolar molecule?
CCL4
Pi (II) bonding occurs in each of the following species EXEPT
CH4
Lewis electron-dot diagrams for CO2 and SO2 are given above. The molecular geometry and polarity of the two substances are:
Different because S has a greater number of electron domains (regions of electron density) surrounding it than C has
Of the following molecules, which has the largest dipole moment?
HF
Has a molecule with a pyramidal shape?
NH3(g)
Based on the resonance structures shown above, what are the bond orders of the two carbon-oxygen bonds?
1.5 and 1.5
A Lewis diagram for the molecule C4H4 is shwn above. In the actual C2H4 molecule, the H-C-H bond angles are closest to:
120 Degrees
The question refers to the following species: H2O NH3 BH3 CH4 SiH4 Has a central atom with less than an octet of electrons:
BH3
The question refers to the following species: H2O NH3 BH3 CH4 SiH4 Is predicted to have the largest bond angle:
BH3
Which of the following arranges the molecules N2, O2, and F2 in order of their bond enthalpies, from least to greatest?
F2<O2<N2
NH3 reacts with BF3 to form a single species. Which of the following structural diagrams is the most likely representation of the product of the reaction?
H F H-N-B-F H F
The following questions refer to the below molecules: CO2 H2O CH4 C2H2 PH3 The molecule with the largest dipole moment:
H2O
The melting point of MgO is higher than that of NaF. Explainations for this observation include which of the following? I Mg2+ is more positively charged than Na+ II O2- is more negatively charged than F- III The O2- ion is smaller than the F- ion
I and II only
Refer to the following gaseous molecules: BeCl2 SO2 N2 O2 F2 Is the molecule in which the intramolecular forces are strongest:
N2
refer to the following diatomic Species: Li2 B2 N2 O2 F2 Has the largest bond-dissociation energy:
N2
Which of the following Lewis-electron dot diagrams represents the molecule that contains the smallest bond angle?
NF3
The question refers to the following species: H2O NH3 BH3 CH4 SiH4 Has a trigonal-pyramidal molecular geometry:
NH3
Based on the data in the tables above, which of the following statements provdes the best prediction for the boiling point of NaCl?
NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF
Resonance is most commonly used to desribe the bonding in molecules of which of te following?
O2
refer to the following diatomic Species: Li2 B2 N2 O2 F2 Has a bond order of 2:
O2
Which of the following species is NOT planar?
PCl3
Based on the diagrams shown above, which of the following wuld have the greatest dipoe moment, and why?
PCl3, because the Cl atoms draw electron densty away from the P atom and the dipoled do not cancle one another.
Which of the following has a zero dipole moment?
PF5
The following questions refer to the below molecules: CO2 H2O CH4 C2H2 PH3 The molecule that has trigonal pyramidal Geometry:
PH3
For which of the following molecules are resonance structures necessary to describe the bonding satisfactory?
SO2
Refer to the following gaseous molecules: BeCl2 SO2 N2 O2 F2 Is a polar molcule:
SO2
The potential energy of a system of two atoms as a function of their intrnuclear distance is shown in the diagram above. Which of the following is true regarding the forces between the atoms when their intranuclear distance is x?
The attractive and repulsive forces are balanced, so the atoms will maintain an average internuclear distance x
Refer to the following gaseous molecules: BeCl2 SO2 N2 O2 F2 The geometry of the SO3 molecule is best described as:
Trigonal Planar
The BF3 molecule is nonpolar, whereas the NF3 molecule is polar. Which of the following statements accounts for the difference in polarity of the two molecules?
Unlike BF3, NF3 hs a nonplanar geometry due to an unshared pair of electrons on the N atom
The potantial energy as a function of internuclear distance for three diatomic molecules, X2, Y2, Z2, is shown in the graph above. Based on the data in the graph, which of the following correctly identifies the diatomic molecules, X2, Y2, and Z2?
X2=H2 Y2=N2 Z2=O2
When reaction 3 occurs, does the hybridization of the carbon atoms change?
Yes; it changes from sp to SP^2
H-C=C-H What is the hybridization of the carbon atoms in a molecule of ethyne, represented above?
sp
