Chapter 6-7 Covalent Bonding Flashcards
The normally weak forces of attraction that exist between molecules.
Intermolecular forces
What is the formula for the compound carbon tetraiodide?
CI4
States that chemical compounds tend to form so that each atom, by gaining, losing, or sharing electrons, has 8 valence electrons.
Octet rule
The energy required to break a chemical bond and form neutral, isolated atoms.
Bond (dissociation) energy
A molecule that has a partial positive end and a partial negative end.
A dipole
A particularly strong dipole-dipole interaction that results from the attraction between a hydrogen atom bonded to fluorine, oxygen, or nitrogen and another F, O, or N atom
Hydrogen bonding
Indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts.
Chemical formula
Draw the Lewis structure and predict the molecular for geometry for the compound SeF6.
Intermolecular attractive force that results from the constant motion of electrons and the creation of instantaneous dipoles
London (Dispersion) forces
Draw the Lewis structure for the azide ion, N3-1. What is the predicted shape of the ion?
A covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge. The electronegativity difference between the atoms is between 0 and 0.3.
Non-polar covalent bond
Uranium(VI) fluoride is a compound used in the uranium enrichment process that produces fuel for nuclear reactors and nuclear weapons. Calculate the percent composition to one decimal place for each element.
Refers to bonding in molecules or ions that cannot be correctly represented by a single Lewis structure.
Resonance structures
What is the name of the compound SO3?
Sulfur trioxide
What is the formula for the compound dinitrogen trioxide?
N2O3
What is the name of the compound ICl3?
Iodine trichloride
What is the result of more electrons in an atom or molecule on London forces?
More electrons result in stronger London forces. This is reflected in higher melting and boiling points.
Tetracycline is an antibiotic used in the treatment of acne and rosacea. The compound is 59.46% carbon, 5.44% hydrogen, 6.30% nitrogen, and 28.80% oxygen. Calculate the empirical formula of this compound.
In a separate experiment, the molecular mass of tetracycline was determined to be 444.432u. What is its molecular formula?
A certain compound consists only of sulfur and nitrogen. The mass composition for this compound was found to be 69.6% sulfur and the remainder nitrogen. What is the empirical formula of this compound?
If the molecular mass of the compound was found to be 184.32u, what is its molecular formula?
When taking x-rays of the upper gastrointestinal tract, a patient is given a barium swallow as a contrast medium. The suspension of barium sulfate coats the upper GI tract with barium, enhancing its visibility on the x-ray. What is the mass composition of each element in barium sulfate, to two decimal places?
These elements can break the octet rule by having less than an octet when acting as the central atom in a molecule.
The elements of groups IIA and IIIA, particularly beryllium, boron, and aluminum.
A chemical compound whose simplest units are molecules. Generally does not contain a metal.
A molecular compound.
A covalent bond in which three pairs of electrons are shared between two atoms.
Triple bond
A neutral group of atoms that are held together by covalent bonds.
A molecule
The two factors that account for the exceptional strength of hydrogen bonding are…
The highly polar N-H, O-H, or F-H bonds, and the small sizes of the atoms involved.
What is the formula for the compound phosphorus trichloride?
PCl3
Draw the Lewis structure for the borate ion, BO3-3 and predict the shape of the ion.
How can this diagram be used to explain bond length (the distance between covalently bonded nuclei)?
As the two uncombined atoms approach, their energy starts to decrease, as the electrons for each atom begin to be attracted to both atoms at the same time. If the atoms get too close together, there is a sharp increase in energy as repulsion between the two nuclei and electrons begins to dominate. The perfect distance which minimizes repulsion and maximizes attraction is the bond length. The bond length corresponds to the minimum potential energy for the two atoms. The energy minimum indicates that the covalently bonded atoms are more stable than the atoms are when uncombined.
Chemical bonding that results from the electrical attraction between cations and anion. The electronegativity difference between the atoms is greater than 1.7.
Ionic Bonding
What is the name of the compound PBr5?
Phosphorus Pentabromide
A pair of electrons that is not involved in bonding and that belongs only to one atom.
Lone pair
A covalent bond in which two pairs of electrons are shared between two atoms.
Double bond
Results from the sharing of electron pairs between two atoms.
Covalent bond
States that repulsion between sets of valence level electrons surrounding an atom causes these sets to be oriented as far apart as possible.
VSEPR (valence shell electron pair repulsion) Theory
The strength of intermolecular attractive forces are reflected in what measurable physical property?
Melting or boiling point. The stronger the forces of attraction, the more energy is required to pull the molecules apart, resulting in higher melting and boiling points.
A covalent bond in which the bonded atoms have an unequal attraction for the shared electrons. The difference in electronegativity between the atoms ranges between 0.3 and 1.7.
Polar covalent bond
An attractive force that exists between polar molecules. The more polar the molecule is, the stronger the force becomes.
Dipole-Dipole interaction
Shows the types and numbers of atoms combined in a single molecule of a molecular compound.
Molecular formula
These elements may exceed an octet of electrons.
Elements in the third period and below.
A pair of electrons shared between two atoms.
A bonding pair.
