Solutions for
Introductory
Chemistry, 7th edition
by Nivaldo J. Tro
what is a node in a p orbital - answer-the two lobes of the p orbital are separated by a
region of zero electron density called the node
valence - answer-electrons in incomplete shells and they can participate in bonding
core - answer-electrons that are in a full shell. they do not participate in bonding
additive combination - answer-forms a molecular orbital with lower energy than the
starting atomic orbitals and is roughly egg shaped - bonding MO
subtractive combination - answer-forms a molecular orbital with higher energy than the
starting atomic orbitals and a node between nuclei - antibonding MO
promotion - answer-allows an element to increase in the number of bonds it can form
through the movement of a paired non-core electron to an empty orbital
C-H bond strength - answer-439kJ/mol
c=c bond stregnth - answer-611kJ/mol
orbital - answer-volume of space around a nucleus in which an electron can most likely
be found
pauli exclusion principle - answer-each atomic orbital can accommodate two electrons
with opposite spin
Hunds rule - answer-half fill orbitals of equivalent energy before spin pairing
aufbau principle - answer-electrons are added to the lowest energy atomic orbital first
whats a lewis electron - answer-shows valence electrons
, according to valence electron theory what is a covalent bond - answer-when two atoms
approach eachother close enough so that the singly occupied orbital of one atom
overlaps the singly occupied orbital of the other forming a covalent bond
the H-H bond strength - answer-436 kJ/mol
paulings theory - answer-the 2s orbital can combine with with the three 2p orbitals to
form four sp3 hybrid orbitals. They are all the same energy, lower than the starting 2p
orbitals but greater than the 2s orbital
symmetry of sp3 orbitals - answer-the sp3 orbitals are unsymmetrical about the nucleus.
One lobe is bigger than the other and therefore overlaps better with orbitals from other
atoms, and therefore hybridised sp3 orbitals form stronger bonds than unhybridised s
and p orbitals
structure of methane - answer-tetrahedral structure
109.5
structure of ethene - answer-planar - 120
C-C triple bond strength - answer-837
polar covalent bond - answer-the distribution of the bonding electrons between atoms is
not symmetrical
electronegativity - answer-the measure of the ability of an atom to pull the bonding
electrons towards itself
how does hydrogen bonding arise and what is it - answer-through differences in
electronegativity between atoms. Its not a bond but a molecular interaction and it is
weaker than a covalent bond
when is hydrogen bonding most effective - answer-when the bond is a straight line
hydrogen bond acceptor and donor - answer-the acceptor is the lone pair of electrons
on the highly electronegative atom
and the donor is the hydrogen atom which is attached to an electronegative atom
three types of errors - answer-gross errors
random errors
systematic errors
whats the difference between reproducibility and repeatability - answer-reproducibility is
the precision obtained in different conditions and repeatability is the precision obtained
in the same conditions over a short interval of time
Introductory
Chemistry, 7th edition
by Nivaldo J. Tro
what is a node in a p orbital - answer-the two lobes of the p orbital are separated by a
region of zero electron density called the node
valence - answer-electrons in incomplete shells and they can participate in bonding
core - answer-electrons that are in a full shell. they do not participate in bonding
additive combination - answer-forms a molecular orbital with lower energy than the
starting atomic orbitals and is roughly egg shaped - bonding MO
subtractive combination - answer-forms a molecular orbital with higher energy than the
starting atomic orbitals and a node between nuclei - antibonding MO
promotion - answer-allows an element to increase in the number of bonds it can form
through the movement of a paired non-core electron to an empty orbital
C-H bond strength - answer-439kJ/mol
c=c bond stregnth - answer-611kJ/mol
orbital - answer-volume of space around a nucleus in which an electron can most likely
be found
pauli exclusion principle - answer-each atomic orbital can accommodate two electrons
with opposite spin
Hunds rule - answer-half fill orbitals of equivalent energy before spin pairing
aufbau principle - answer-electrons are added to the lowest energy atomic orbital first
whats a lewis electron - answer-shows valence electrons
, according to valence electron theory what is a covalent bond - answer-when two atoms
approach eachother close enough so that the singly occupied orbital of one atom
overlaps the singly occupied orbital of the other forming a covalent bond
the H-H bond strength - answer-436 kJ/mol
paulings theory - answer-the 2s orbital can combine with with the three 2p orbitals to
form four sp3 hybrid orbitals. They are all the same energy, lower than the starting 2p
orbitals but greater than the 2s orbital
symmetry of sp3 orbitals - answer-the sp3 orbitals are unsymmetrical about the nucleus.
One lobe is bigger than the other and therefore overlaps better with orbitals from other
atoms, and therefore hybridised sp3 orbitals form stronger bonds than unhybridised s
and p orbitals
structure of methane - answer-tetrahedral structure
109.5
structure of ethene - answer-planar - 120
C-C triple bond strength - answer-837
polar covalent bond - answer-the distribution of the bonding electrons between atoms is
not symmetrical
electronegativity - answer-the measure of the ability of an atom to pull the bonding
electrons towards itself
how does hydrogen bonding arise and what is it - answer-through differences in
electronegativity between atoms. Its not a bond but a molecular interaction and it is
weaker than a covalent bond
when is hydrogen bonding most effective - answer-when the bond is a straight line
hydrogen bond acceptor and donor - answer-the acceptor is the lone pair of electrons
on the highly electronegative atom
and the donor is the hydrogen atom which is attached to an electronegative atom
three types of errors - answer-gross errors
random errors
systematic errors
whats the difference between reproducibility and repeatability - answer-reproducibility is
the precision obtained in different conditions and repeatability is the precision obtained
in the same conditions over a short interval of time
