The Chemical Bond Flashcards
What is a polyatomic ions?
Covalent bonded set of 2 or more atoms that can be considered to behave as a single unit & that has a net charge that is not zero
Formula for ammonium
NH4+
Formula for hydroxide
OH-
Formula for Chlorate
ClO3-
Formula for nitrate
NO3-
Formula for carbonate
CO3 2-
Formula for chromate
CrO4 2-
Formula for sulphate
SO4 2-
Formula for phosphate
PO4 3-
Formula for cyanide
CN-
Formula for acetate
C2H3O2-
What a intramolecular bonds?
Bonds between atoms forming compounds
What are the 3 types of intermolecular bonds?
Ionic bonds
Covalent bonds
Metallic bonds
Strength of the different types of intramolecular bonds (typically)
Ionic > metallic > covalent
What is the weakest kind of intramolecular bonds
Covalent
What is the strongest kind of intramolecular bonds
Ionic
What is the difference between intramolecular bonds & intermolecular forces?
intramolecular bonds form molecules, intermolecular forces is the attraction between molecules/atoms
Definition of intermolecular forces
Attraction between molecules/atoms to other molecules/atoms
What or the 3 types of intermolecular forces?
London dispersion forces
Dipole-dipole interactions
Hydrogen bonds
Are intramolecular bonds week or strong?
Strong
Are intermolecular forces strong or weak?
Weak
Strength of the different types of intermolecular forces (typically)
Hydrogen bond > dipole-dipole > London dispersion
What is an ionic bond?
Where an electron is taken by an electronegative non-metal from an electropositive metal
When do ionic bonds occur?
When the electronegativity difference between 2 elements is >2
What is a metallic bond?
Electrons shared between metal atoms
What does metallic bonds form?
An electron Sea: valence electrons are delocalized & move freely among the metals
What is a covalent bond?
Where an electron is shared between 2 atoms resulting in a molecule
How are molecules made?
Covalent bonds
How are charged particles made?
Ionic bonds
What a the 2 kinds of covalent bonds
Non-polar covalent & polar covalent
When are molecules non-polar?
When charge is evenly distributed
When are molecules polar?
When one the atoms in the molecule have difference in electronegativity making the charge not evenly distributed
What molecules are non-polar?
Single element molecules: 02, N….
Carbon hydrogen only molecules:CH4, C3H8…
Symmetrical molecules:CCl4, CO2…
Electrongativity difference is very low, <0.5
What molecules are polar?
Non- symmetrical molecules:CH3Cl, H2O….
Molecules w/ different elements that don’t cancel out
How many electrons are shared in a single, double & triple bond?
Single: 2
Double: 4
Triple: 6
What is bond strength?
Energy required to break the bonds
Bond strength
Triple > double > single
Length of bonds, single, double & triple
single > double > triple
What is bond length?
Distance between the nuclei in participating atoms
What increases bond length?
The number of bonds (the less the longer)
Atomic radius (the bigger the radius the longer)
How are bond length & strength related?
As bond length increases, strength decreases
What kind of bonds does single bonds have?
1 sigma bond
What kind of bonds does double bonds have?
1 sigma bond
1 pi bond
What kind of bonds does triple bonds have?
1 sigma bond
2 pi bond
What are some octet exceptions when making Lewis structures?
Period 3 elements occasionally form more than 4 bonds
Sometimes an incomplete octet will form
What is the formula for finding lone pairs on central atom? & when does it not work?
Lp = (ve - 8n)/2
Lp = lone pairs on central atom
Ve = valence electrons in the entire molecule
N = number of atoms attached to central atom
Does not work with molecules with hydrogen!
What is important to remember when drawing vsepr diagrams?
Bonds want to be as for away from eachother as possible
Lone pairs cause additional repulsion
What are electron domains?
Bonding: single, double or triple bonds
Non bonding: lone pairs
How many electron domains is a single bond?
1
When are hydrogen bonds the strongest?
When hydrogen is bonded to F, O or N
Compounds containing only Carbon & hydrogen are always polar or non polar?
Non polar
Which are the only inter molecular forces present in Carbon, hydrogen only compounds?
London dispersion forces (van der Waals )
