CHEM 162 TEST 2 QUESTIONS AND
ANSWERS
Lattice energy: - Correct Answers -the energy required to convert a mole of ionic solid
into its constituent ions in the gas phase
In ionic bond formation, the lattice energy of ions ________ as the magnitude of the ion
charges _______ and the radii __________. - Correct Answers -increases, increase,
decrease
The type of compound that is most likely to contain a covalent bond is - Correct
Answers -one that is composed of only nonmetals
It might seem that a square-planar geometry of four electron domains around a
central atom would be more favorable than a tetrahedron. Can you rationalize
why the tetrahedron is preferred, based on angles between electron domains? - Correct
Answers -A tetrahedral arrangement of electron domains is preferred because the bond
angles are 109.5 compared to 90. bond angles in a square-planar arrangement of
electron domains. The larger bond angles result in smaller repulsions among electron
domains and a more stable structure.
Although the electron-domain
geometry around the right O is
tetrahedral, the C¬O¬H bond is
slightly less than 109.5 degrees. Explain. - Correct Answers -The nonbonding electron
pairs exert a greater repulsive
force than the bonding electron pairs.
polarity _______ and the period ________ - Correct Answers --increases
-decreases (moves up the period, having lower atomic number)
The most stable electron-domain geometry for five electron domains is the - Correct
Answers -trigonal bipyramid
Why is the square pyramidal distorted but the square planar isn't? - Correct Answers -
The unshared electron pair in the square pyramidal geometrical shape pushes down on
the remaining bonded pairs, causing the angles to be slightly distorted, and thus, less
than 90 degrees. However, in a square planar molecule, there are two lone pairs
ANSWERS
Lattice energy: - Correct Answers -the energy required to convert a mole of ionic solid
into its constituent ions in the gas phase
In ionic bond formation, the lattice energy of ions ________ as the magnitude of the ion
charges _______ and the radii __________. - Correct Answers -increases, increase,
decrease
The type of compound that is most likely to contain a covalent bond is - Correct
Answers -one that is composed of only nonmetals
It might seem that a square-planar geometry of four electron domains around a
central atom would be more favorable than a tetrahedron. Can you rationalize
why the tetrahedron is preferred, based on angles between electron domains? - Correct
Answers -A tetrahedral arrangement of electron domains is preferred because the bond
angles are 109.5 compared to 90. bond angles in a square-planar arrangement of
electron domains. The larger bond angles result in smaller repulsions among electron
domains and a more stable structure.
Although the electron-domain
geometry around the right O is
tetrahedral, the C¬O¬H bond is
slightly less than 109.5 degrees. Explain. - Correct Answers -The nonbonding electron
pairs exert a greater repulsive
force than the bonding electron pairs.
polarity _______ and the period ________ - Correct Answers --increases
-decreases (moves up the period, having lower atomic number)
The most stable electron-domain geometry for five electron domains is the - Correct
Answers -trigonal bipyramid
Why is the square pyramidal distorted but the square planar isn't? - Correct Answers -
The unshared electron pair in the square pyramidal geometrical shape pushes down on
the remaining bonded pairs, causing the angles to be slightly distorted, and thus, less
than 90 degrees. However, in a square planar molecule, there are two lone pairs
