Chapter 6 Covalent Bonding Flashcards
What is the name of N2O3?
Dinitrogen trioxide
What is the chemical formula for tetrasulfur pentoxide?
S4O5
What is the name of C3Cl8
Tricarbon octachloride
What is the chemical formula for Nitrogen triiodide?
NI3
What is the name of Br6F10 ?
Hexabromine decafluoride
What is the chemical formula for Tetraphosphorous Pentachloride ?
P4Cl5
What is the name of CO
carbon monoxide
What is the chemical formula for Fluorine trisulfide ?
FS3
What is the name of S2Br6?
Disulfur hexabromide
What is the chemical formula for phosphorus triiodide?
PI3
What is the chemical formula for chlorine pentoxide?
ClO5
What is the name of P4S5?
Tetraphosphorus pentasulfide
What is the name of SeF3?
selenium trifluoride
What is the prefix for 1?
mono
What is the prefix for 8?
octa
What is the prefix for 10?
deca
What is the prefix for 4?
tetra
covalent compounds contain:
2 nonmetals
What is the correct name for C4H6?
tetracarbon hexahydride
NH3 has how many lone pairs?
1
What is a covalent bond?
A bond formed when two atoms share a pair of electrons
In chemical compounds, covalent bonds form when
pairs of electrons are shared between two non-metal atoms.
The melting point of sugar is__________________ the melting point of table salt.
less than
What are properties of a covalently-bonded compound?
Low melting point, Generally insoluble/immiscible in water, Generally soft and flexible
How does the covalent bond form between two atoms?
When the two atoms share electrons
Why is the H2 molecule more stable than two separate hydrogen atoms?
Hydrogen only needs two electrons to become stable so when separate hydrogen atoms share their single electrons, it becomes stable
Explain why the stability described in item 2 does or does not hold true for most covalent bonds?
The H2 molecule is stable but not true for other bonds because each e- has to have 8 valence electrons except H
How does a covalent bond differ from an ionic bond
Covalent bonds share electrons, ionic bonds transfer electrons from one another
What is a molecular orbital?
a regions of high probability that is occupied by in individual electron as it travels around two or more associated nuclei
Describe the potential energy change that occurs when two hydrogen atoms approach each other and form a covalent bond
The potential energy of two separate hydrogen atoms (right) decreases as they approach each other, and the single electrons on each atom are shared to form a covalent bond.
In terms of energy, why is the H-H bond stable?
It is stable because of the shared electrons. Hydrogen only needs two electrons to become stable
What is bond length?
The average distance between two bonded atoms at their minimum potential energy
What is bond energy?
the energy required to break the chemical bond between two atoms and separate them
The tendency of an atom to attract bonding electrons to itself when it bonds with another atom is called ______________
electronegativity
_____________is an attraction between two atoms in which electrons are shared equally between atoms.
nonpolar covalent
____________is an attraction between two atoms in which bonding electrons are localized on the more electronegative atom.
polar covalent
__________ is a molecule in which one end has a partial positive charge and the opposite end has a partial negative charge.
dipole
In general, if the difference in electronegativity between two atoms is between 0 and 0.4, the bond is __________.
nonpolar covalent
If the electronegativity difference between two atoms is between 0.5 and 1.7, the bond formed is __________.
polar covalent
If the electronegativity difference between two atoms is greater than 2.1 the bond formed is __________.
ionic
A possible Lewis structure of a molecule for which more than one Lewis structure can be written is called a __________ structure
resonance
A structure in which atomic symbols represent nuclei and inner-shell electrons and in which dots are used to represent valence electrons is called a ________ structure.
Lewis
explain the difference between single double and triple bonds
A single bond is formed when two atoms share one pair of electrons, whereas a double bond is formed when two atoms share two pairs (four electrons). Three pairs of electrons (six atoms) are shared to form triple bonds.
What does the VSEPR theory predict?
The arrangement of electron pairs around each central atom and the correct arrangement of atoms in a molecule.
How does one unbonded pair of electrons affect the shape of a molecule?
The electrons in the unbonded pair repel bonding electrons as far away from it as possible.
How do multiple unbonded pairs of electrons affect the shape of a molecule?
They can repel each other as well as bonding electrons, forming a bent molecule.
What evidence is there to support the idea that opposite polar ends of molecules attract each other?
The energy required to separate polar molecules is greater than that required to separate non polar molecules.
How do polarity and shape of molecules relate to the properties of a substance?
They can affect how a molecule fits into another structure and how it tastes. It can also affect how easy the molecule is to separate and its attraction to positively or negatively charged objects.
Why is bond length an average rather than a fixed number?
Because bonded atoms can experience vibration causing the bond to stretch and bend.
Electron affinity is:
energy change when an electron is acquired by a neutral atom
Covalent bonds have a ______ boiling point
low
What does the Lewis structure help us see?
The arrangement of electrons in a a molecule
As the number of bonds increases in a molecule, the bond length:
decreases
Trigonal planar angle:
120
Bent angle with one lone pair:
116
Tetrahedral angle:
109.5
Trigonal pyramidal angle:
107
Bent angle with two lone pairs:
105
