AAST/AEDT Bonding/ Shapes
Write the resonance structures for benzene (C₆H₆)
(theres 2) one looks like dis just reflect the bonds for the other one
What is the bond order of H₂⁻ ? is it stable?
.5, yes
What is the bond order for He₂?
0
What is the bond order of F₂⁺? how many unpaired electrons?
1.5 1
What is the approximate bond angle in hydroselenic acid?
105°
What is the ideal Cl-C-Cl bond angle in C₂Cl₄?
120°
linear: # of occupied areas? bonds/lone pairs? angle? polarity?
2 2 bonds 180° NP
Draw out N₂O₄. How many nonbonding electrons are present?
20
How many resonance structures does SCN⁻ have?
3
Bent (the one with three occupied areas): # of occupied areas? bonds/lone pairs? angle? polarity?
3 2 bonds, 1 lone pair 120° P
trigonal planar: # of occupied areas? bonds/lone pairs? angle? polarity?
3 3 bonds 120° NP
bent (the one with 4 occupied areas): # of occupied areas? bonds/lone pairs? angle? polarity?
4 2 bonds, 2 lone pairs 104.5° P
trigonal pyramidal: # of occupied areas? bonds/lone pairs? angle? polarity?
4 3 bonds, 1 lone pair 107° P
tetrahedral: # of occupied areas? bonds/lone pairs? angle? polarity?
4 4 bonds 109.5° NP
linear (the one with 5 occupied areas): # of occupied areas? bonds/lone pairs? angle? polarity?
5 2 bonds, 3 lone pairs 180° NP
T-shaped: # of occupied areas? bonds/lone pairs? angle? polarity?
5 3 bonds, 2 lone pairs 90°/180° P
seesaw: # of occupied areas? bonds/lone pairs? angle? polarity?
5 4 bonds, 1 lone pair 90°/120° P
trigonal bipyramidal: # of occupied areas? bonds/lone pairs? angle? polarity?
5 5 bonds 90°/120° NP
How many sigma and pi bonds in C₂H₃Cl ?
5 sigma bonds, 1 pi bond
how many electrons are transferred when magnesium reacts with nitrogen to form magnesium nitride?
6
square pyramidal: # of occupied areas? bonds/lone pairs? angle? polarity?
6 5 bonds, 1 lone pair 90° P
octahedral: # of occupied areas? bonds/lone pairs? angle? polarity?
6 6 bonds 90° NP
square planar: # of occupied areas? bonds/lone pairs? angle? polarity?
6 4 bonds, 2 lone pairs 90° NP
Based on molecular orbital theory, how are the twelve outermost electrons in the O2 molecule distributed?
8 in bonding MOs, 4 in antibonding MOs
Calculate the energy change for the following reaction: K(g) + Br(g) K⁺(g) + Br⁻(g) IE of K is 419 kJ/mol EA of Br is 324 kJ/mol
95
Which of the following is possible? A. A molecule has only polar bonds and has no dipole moment B. A molecule has only non polar bonds and has a dipole moment. C. Both are possible D. none of the above
A. A molecule has only polar bonds and has no dipole moment
What are the three elements that can have less than an octet?
Be, B, Al
Out of the following, which bond is the most polar?
C-Cl
List from longest bond length to shortest bond length in respect to the carbon-oxygen bond?' CO, CO₃⁻², CH₃OH, CO₂
CH₃OH, CO₃⁻², CO₂, CO
Which has a stronger carbon-oxygen bond: CO₃²⁻ or CH₃OH
CO₃²⁻
Coulomb's law is for the energy of Ionic Bonds. what is the formula?
E = 2.31 x 10⁻¹⁹ J*nm (Q₁Q₂/r) where Q₁ and Q₂ are the charges of the ions and r is the distance between ions in nanometers
Hydrogen has an electronegativity value between boron and carbon and identical to phosphorus. Rank the following bonds in order of decreasing polarity: P-H, O-H, N-H, F-H, C-H,
F-H > O-H > N-H > C-H > P-H
List the following bonds in order of increasing ionic character. the lithium-to-fluorine bond in Li-F the potassium-to-oxygen bond in K₂O the hydrogen-to-hydrogen bond in H₂ the chlorine-to-fluorine bond in ClF₃ the manganese-to-oxygen bond in Mn-O
H-H<Cl-F<Mn-O<K-O<Li-F
________________________ in periods _____ to _____ can have 8e⁻ or 12e⁻ or 10e⁻ (MORE THAN AN OCTET)
Nonmetals 3 6
Place the following in order of shortest to longest nitrogen-nitrogen bond: N₂ N₂F₄ N₂F₂
N₂ < N₂F₂ < N₂F₄
Which would be best represented by three resonance structures? NCl₃, H₃O⁺, ClO₃⁻, SiO₃⁻²
SiO₃⁻²
Three of the molecular shapes which a sp3d hybridized molecule can have are ___________________, _____________________, ______________________, ___________________
T-shaped, linear, trigonal bipyramidal, seesaw
Describe the formation of H-H bond
The simultaneous attraction of each electron by the protons generates a force that pulls the protons toward each other that just balances the proton-proton and electron-electron repulsive forces at the distance corresponding to the bond length
Predict which bond will be most polar: Ti-Cl, Si-Cl, Ge-Cl
Ti-Cl
What does VSEPR stand for?
Valence Shell Electron Pair Repulsion
What can an "occupied area" contain?
a single bond, a double bond, a triple bond, or a lone electron pair
Which of the following is a non-polar molecule having one or more polar bonds? a. CBr₄ b. HI c. PH₃ d. H₂
a. CBr₄
When there are 3 lone pairs around the central atom with a total of 5 electron pairs, the lone pairs occupy what?
all equatorial positions.
A negative value for E implies _______________________ where a positive value implies ______________________
attraction repulsion
PF₅, a trigonal bipyramidal, consists of a trigonal planar shape (3 fluorines with the phosphorous in the center) and then a fluorine below and above the phosphorous central atom. The top and bottom fluorines are in ________________ positions where everything else is in a __________________ position
axial, equatorial
Which of the following atoms can expand its valence shell when bonding? a. C b. I c. N d. O
b. I
Which one of the following species is best represented by a resonance hybrid having two contributing structures? a. nitride ion b. nitric acid c. nitrogen d. nitrous acid
b. nitric acid
Within each of the following species all bonds are equivalent. Which one requires two resonance structures? a.CBr₄ b.ClNO₂ c.CBrCl₃ d.CS₂
b.ClNO₂
What type of process us F₂(g)→2F(g)?
bond energy
Based on molecular orbital theory, what can be stated about the bond order, stability, and magnetic properties of B₂⁺?
bond order=0.5, stable, paramagnetic
What type of bonding does CH3OH (methanol) have?
both non-polar and polar covalent bonds
Which one of the following has a Lewis structure most like that of CO? a. CO⁺ b. NO c. NO⁺ d. NO⁻
c. NO⁺
What type of bond is the CC in H₂CCH₂?
covalent
What type of bond is the NN in H₂NNH₂?
covalent
Why can certain elements have more than an octet?
cuz they have empty d orbitals that electrons can hop on
Which is the strongest bond of the following? a. C-C b. C-S c. C-O d. C_= N (pretend that's a triple bond)
d
Which one of the following ionic solids would have the largest lattice energy? a. CaBr₂ b. NaF c. CsI d. CaCl₂ e. NaCl
d. CaCl₂
Which of the following has a pyramidal structure? a. ClO₂ b. ClO₂⁻ c. ClO₄⁻ d. ClO₃⁻
d. ClO₃⁻
Which of the following possesses a polar covalent bond? a. Al b. NaCl c. O₂ d. SO₂
d. SO₂
Which of the following ionic solids would have the largest lattice energy? a. CsI b. BaSO₄ c. CaBr₂ d. SrO e. NaF
d. SrO
if a molecule has all electrons paired and is repelled from magnetic field, it is ___________________
diamagnetic
covalent bond
electrons shared between nuclei (2 or more nonmetals)
ionic bond
electrostatic attraction between closely packed oppositely-charged ions (metal + nonmetal)
Lone pairs always go _____________________
equatorial
True or False: XeF₄ has a dipole moment
false
True or false: Bonds between unlike atoms are non-polar bonds.
false
True or false: if resonance structures are needed to represent a compound, then one of the structures is actually correct but it is impossible to predict which one.
false
True or false: resonance structures are distinct structures that can be isolated under specific conditions
false
true or false: Electrons enter MOs of identical energies in pairs before any enter singly.
false
true or false: a bond is usually more ionic than covalent in character when the bonded atoms have very similar relative electronegativities
false
true or false: When an atom makes use of five sp³d hybrid orbitals to bond five other atoms, the geometry of the molecule is most often octahedral
false, it is usually trigonal bipyramidal
stronger bond implies ___________ energy
higher
Can fluorine have an expanded octet of valence electrons?
no
if a molecule has unpaired electrons and is attracted to magnetic field it is _______________
paramagnetic
What type of bond is CO₂?
polar covalent
What type of bond is H₂S?
polar covalent
Shape of SF₄?
see-saw
stronger bond implies ___________ bond length
shorter
Which hybrid orbitals are used by the carbon atom in CHCl₃?
sp³
What is the expected hybridization of P in PCl₅?
sp³d
What type of process is Na(s) + 1/2F₂(g) → NaF(s)
standard enthalpy of formation
standard enthalpy of formation
the change in energy when 1 mol of a compound is formed from elements in standard states
lattice energy
the change in energy when separated gas ions are packed to form an ionic solid
What is bond length?
the distance where total energy is mimized
True or False: CaCl₂ is a binary ionic compound
true
True or False: Resonance occurs when two or more plausible Lewis structures can be written but the correct structure cannot be written at all.
true
true or false: The central atom is typically the atom with the lowest electronegativity.
true
true or false: it is allowed to have less than 8 electrons around one atom in a lewis structure
true
true or false: molecular orbital theory best accounts for both the bond energy and magnetic properties of O₂
true