CAT(S) & FINAL EXAM REVIEW
WITH VERIFIED ANSWER
lattice energy (U or H_latt) - THE :>CORRECT ANSWER -The energy required to change 1
mole of an ionic compound to its gaseous ions
Below is lattice dissociation process
NaCl(s) ------> Na+(g) + Cl-(g) ΔH = +787 kJ/mol ----> this amount of energy is required to
break the ionic lattice
Na+(g) + Cl-(g) ------> NaCl(s) ΔH = -787kJ/mol
this amount of energy is released when Na+ and Cl- form solid NaCl
Factors affecting lattice energy - THE :>CORRECT ANSWER -1. ionic charge
- the greater the charger the greater the electrostatic attraction hence the higher the lattice
energy: MgO has higher lattice energy compared to NaCl why?
2. Ionic radii (size)
- smaller ions, closer to the nucleus, stronger attraction due to less shielding
NaF>NaCl>NaBr>NaI
electron configuration of lead - THE :>CORRECT ANSWER -Pb
atomic number: 82
[Xe]4f145d106s26p2
, electron configuration of Gd - THE :>CORRECT ANSWER -Gd
Atomic number: 64
[Xe]4f75d16s2
electron configuration of H- - THE :>CORRECT ANSWER -1s2
molecules have three types of orbitals: - THE :>CORRECT ANSWER -1. bonding orbitals [σ
or π] - formed from constructive overlap of atomic orbitals; more stable and lower in energy
2. antibonding orbitals [σ* or π*] - formed from destructive overlap of atomic orbitals - less
stable and higher in energy; creates nodes
3. Non-bonding orbitals - formed by atomic orbitals that do not overlap significantly - no
effect on bond strength
What is the electron configuration of H2? - THE :>CORRECT ANSWER -σ^2_1s
what type of bond is this: σ - THE :>CORRECT ANSWER -sigma bond - exists in all single
bonds
- formed from head-to-head overlap of atomic orbitals
- does not conduct electricity
- strongest type of covalent bond
- localized
what tyoe of bond is this: π - THE :>CORRECT ANSWER -pi bond - exists in double and
triple bonds
- formed from side-by-side interraction of atomic orbitals
- conducts electricity sometimes (graphite)
- partially delocalized
WITH VERIFIED ANSWER
lattice energy (U or H_latt) - THE :>CORRECT ANSWER -The energy required to change 1
mole of an ionic compound to its gaseous ions
Below is lattice dissociation process
NaCl(s) ------> Na+(g) + Cl-(g) ΔH = +787 kJ/mol ----> this amount of energy is required to
break the ionic lattice
Na+(g) + Cl-(g) ------> NaCl(s) ΔH = -787kJ/mol
this amount of energy is released when Na+ and Cl- form solid NaCl
Factors affecting lattice energy - THE :>CORRECT ANSWER -1. ionic charge
- the greater the charger the greater the electrostatic attraction hence the higher the lattice
energy: MgO has higher lattice energy compared to NaCl why?
2. Ionic radii (size)
- smaller ions, closer to the nucleus, stronger attraction due to less shielding
NaF>NaCl>NaBr>NaI
electron configuration of lead - THE :>CORRECT ANSWER -Pb
atomic number: 82
[Xe]4f145d106s26p2
, electron configuration of Gd - THE :>CORRECT ANSWER -Gd
Atomic number: 64
[Xe]4f75d16s2
electron configuration of H- - THE :>CORRECT ANSWER -1s2
molecules have three types of orbitals: - THE :>CORRECT ANSWER -1. bonding orbitals [σ
or π] - formed from constructive overlap of atomic orbitals; more stable and lower in energy
2. antibonding orbitals [σ* or π*] - formed from destructive overlap of atomic orbitals - less
stable and higher in energy; creates nodes
3. Non-bonding orbitals - formed by atomic orbitals that do not overlap significantly - no
effect on bond strength
What is the electron configuration of H2? - THE :>CORRECT ANSWER -σ^2_1s
what type of bond is this: σ - THE :>CORRECT ANSWER -sigma bond - exists in all single
bonds
- formed from head-to-head overlap of atomic orbitals
- does not conduct electricity
- strongest type of covalent bond
- localized
what tyoe of bond is this: π - THE :>CORRECT ANSWER -pi bond - exists in double and
triple bonds
- formed from side-by-side interraction of atomic orbitals
- conducts electricity sometimes (graphite)
- partially delocalized
