Module 2: Bonding and Structure of Organic Compounds Flashcards
The best Lewis structure is the one with the?
fewest charges
To determine the geometry:
[1] Draw a valid Lewis structure
[2] Count groups around a given atom
If two or more degenerate orbitals are available, one electron is placed in each orbitals with their spins parallel until all are half-full.
Hund’s rule
A π bond is formed by side-by-side overlap of?
two 2p orbitals
A _____________ is formed by side-by-side overlap of two 2p orbitals.
π bond
σ bonds are __________ than π bonds
stronger
What orbitals do the first-and second-row atoms use to form bonds?
s and p orbitals
It is based on the fact that electron pairs repel each other, so we need to consider the lone pairs.
VSEPR
All single bonds are?
sigma bonds
Rule 2 in electron configuration
Pauli exclusion principle
type of covalent bond: between unhybridized parallel p orbitals
pi bond
_________________ down a column of the periodic table as the size of an atom increases
increases
To summarize, a C=C bond consists of?
one sigma bond and one pi bond
trend: right to left and up to down
atomic size increases
electrons are arranged in __________ at various distances from the nucleus
“shells”
Group IVA
tetrels
Group IA
alkali metals
The charge assigned to individual atoms in a Lewis structures
Formal charge
It is the joining of two atoms in a stable arrangement.
bonding
trend: down to up and left to right
electronegativity and ionization energy increases
This result from the transfer of electrons from one element to another.
ionic bonds
the most stable arrangement keeps the groups as far away as possible from the others to minimize repulsions.
Valence-shell Electron-pair Repulsion(VSEPR)Theory
These orbitals are formed when 1 s orbital combines with 1 p orbital
sp hybrid orbitals
Orbitals are filled so that those
of lowest energy are filled first
Aufbau principle
Group VA
pnictogens
A __________________ consists of the simultaneous attraction of two nuclei for one or more pairs of electrons.
covalent bond
within each shell, electrons are paired into orbitals with each orbital holding _____ electrons
two
two kinds of bonding
- ionic bonds
- covalent bonds
Two group = ?
linear (180 degrees)
Group VIIIA
noble gas
The best Lewis structure puts a negative charge on the?
most electronegative atom
Joining two or more elements to forms compounds.
bonds
Elements in the same group have _____________________
similar properties
Group VIIA
halogens
Group VIA
chalcogens
A _____________ results when the bonding orbitals are parallel to each other and perpendicular to the axis connecting the two bonding nuclei
pi (π) bond
It is composed of negatively charged electrons
electron cloud
These hybrid orbitals are called ____________ because they are formed from one s orbital and three p orbitals
sp3 hybrid orbitals
Rows represent the ________
period
Columns represent ________
groups
Rule 1 in electron configuration
Aufbau principle
atoms will give up, accept, or share electrons in order to achieve a noble gas configuration
Octet Rule
A σ bond is formed by end-on overlap of?
two sp2 hybrid orbitals
shells are arranged in ____________ energy
increasing
Electrons have properties of both a particle and wave
Quantum mechanics
It is where most of the mass of the atom is contained
nucleus
> or <
interaction between parallel orbitals ____ orbitals that point at each other
<
It is the probability of finding an electron at a given point in space
Ψ2
These are much more common in organic chemistry than ionic bonds.
covalent bonds
type of covalent bond: s-to-s, p-to-p, hybrid-to-hybrid, s-to-hybrid, etc.
sigma bond
Rule 3 in electron configuration
Hund’s rule
Three group = ?
trigonal planar (120 degrees)
Through ____________, atoms attain a complete outer shell of valence electrons
bonding
A _________________ is formed by end-on overlap of two sp2hybrid orbitals.
σ bond
Group IIA
alkaline earth metals
These are used to form bonds.
orbitals
__________________ across a row of the periodic table as the size of the atom decreases
decreases
paired electrons within an orbital have ____________ spins
opposite
Gives the total energy of an electron at a given point in space (x,y,z).
Schrödinger wave equation (Ψ)
A ________________ bond results when the bonding orbitals point along the axis connecting the two bonding nuclei
sigma (σ)
Geometry is affected by?
bond length and bond angle
four groups = ?
tetrahedral (109.5 degrees)
A ___________ concentrates electron density on the axis that joins two nuclei.
σ bond
A maximum of two electrons may be placed in each orbital but only when the spins of the electrons are paired.
Pauli exclusion principle
It contains positively charged protons and uncharged neutrons
nucleus
To summarize, a C≡C bond consists of?
one sigma bond and two pi bonds
These orbitals are formed when 1 s orbital combines with 2 p orbitals
sp2 hybrid orbitals
examples of more than an octet
- dimethyl sulfoxide
- sulfuric acid
- alendronic acid
this result from the sharing of electrons between two nuclei
covalent bonds
these are electrons in the outermost shell; electrons involved in bonding
Valence Electrons
formula of formal charge
number of valence electrons - number of electrons an atom “owns” (number of unshared electrons + 1/2 of the number of shared electrons)
The __________________ comprises most of the volume of the atom
electron cloud
Group IIA
triels
types of covalent bonds
- sigma bond
- pi bond
type of covalent bond: either standard atomic orbitals or hybrids
sigma bond
____ orbitals are not used to form the hybrid orbital
2p
It is the space where an electron spends ~95% of its time.
orbital
Determines the shape around any atom bonded to two other atoms.
Bond angle
Distance between the nuclei of two atoms joined by a covalent bond
bond length
