Unit 2 Chemistry

Question Answer
covalent bonds have no electron transfer, share electrons through chemical bonds
the octet rule must be obeyed by nonmetal valence shells having a principle quantum number (n) of 2
octet rule nonmetals want 8 electrons in outer shell
C, N, O, F elements in row 2 can NEVER exceed 8
H can only hold 2 electrons
electronegativity measure of how badly an atom wants an electron, the ability of an atom to attract an electron
electronegativity increases on the periodic table up and to the right
which group does NOT have electronegativity noble gases
which three atoms have the highest electronegativity F>O>N?Cl
if there is a difference in __________________, atoms the electrons are _____________ shared electronegativities; not equally
an ionic compound indicates an extreme difference in ___________________ electronegativity
the difference range in electronegativities for covalent bonds is ___________________________ <0.4
the difference range in electronegativities for polar covalent bonds is ___________________________ 0.4-2.0
the difference range in electronegativities for polar bonds is ___________________________ >2.0
pure covalent bonds ____________ electrons ______________ share; equally
what type of molecule is water polar
molecules with partial negative charges are _____________ ________________ electron rich
molecules with partial positive charges are ______________ _____________ electron poor
rule #1- the LEAST electronegative atom goes in the _____________, except for ___________ center, hydrogen
rule #2- compute the total number of ______________ _______________; account for _________ _____________. valence electrons; lone pairs
rule #3- NEVER leave _______________ _____________ in a molecule; radicals unpaired electrons
rule #4- _______________ bonds may be used multiple
tip #1 Fl is always a _______________ atom terminal
tip #2 terminal halogens will ONLY make _____________ ___________ single bonds
tip #3- _______________ atoms will usually have ___ bonds around them, except for ____, _____, and carbon ions carbon; CO, CN-
tip #4- NEVER draw a Lewis Structure with an ____________ ______________ unless explicitly told that it is a radical unpaired electron
a single bond represents an overlap of __________ _____________ valence orbitals
calculated value for an atom or polyatomic ion by determining charge based off of the valence electron number formal charge
a nonmetal will take on a full _____________ or ________________ charge in order to satisfy the octet rule negative; positive
the preferred Lewis Structure is one where formal charge is _________________ minimized
if formal charge must exist, negative charges are preferred on the more _______________ atoms electronegative
a molecule or ion having separate positively and negatively charged groups that cancel out zwitterion
lone electrons spread out across the molecule, no fixed position, constant movement delocalization
all lewis structure possibilities that demonstrate the delocalized electron resonance
# total bonds/# bond sites bond order (resonance)
elements below row 2 have empty d orbitals that can be used to hold electrons; octet rule does NOT apply expanded octets
have uneven electron distributions polar molecules
even electron distribution nonpolar molecules
the pull of electrons in a given direction dipole moment
no polar bonds in a molecule or a saturated and symmetrical reasons for nonpolar molecules
VSEPR, Valence Shell Electron Pair Repulsion, Theory lone electron pair STRONGLY repel each other and bonding electrons and the shape of a molecule is one that minimizes repulsion
gives more insight into the orbitals involved in covalent bonding and also describes the nature of orbital overlap hybridization
a single bond involving orbital overlap with s character sigma bond
double bond represented by a sigma and a pi bond, an interaction between hybridized orbitals; bond+ pi bond
hybridization with 2 domains Sp
hybridization with 3 domains Sp2
hybridization with 4 domains Sp3
hybridization with 5 domains Sp3d
hybridization with 6 domains Sp3d2
attractive forces between molecules intermolecular forces
bonds that exist within a molecule intramolecular forces
intramolecular forces are _________________ than intermolecular forces stronger
attraction between negative and positive charges in a salt coulombic attraction
strongest of all intermolecular forces coulombic attraction
all ________ compounds have very high melting/boiling points and are solid at room temperature ionic
intermolecular forces experienced by all polar molecules, which will orient themselves in a way to maximize these attractions dipole-dipole forces
increased polarity or electronegativity results in ______________ intermolecular forces stronger
strong interaction between formal and partial charges; when salts are dissolved in water the water dipoles are oriented around the ions increasing boiling point ion-dipole forces
a dipole interaction that exists only between a hydrogen atom with either fluorine, oxygen, or nitrogen hydrogen bonding
exists in all molecules, it is also the only force that exists in nonpolar molecules; create instantaneous dipoles london dispersion forces
ease of electron distortion; ability to be squished polarizability
same chemical formula with different structures, different boiling/melting points, increased surface area = increased boiling point constitutional isomers
long hydrophobic chains (tails) and bulky polar ends (heads); soap for example due to nonpolar tails dissolving in water and polar heads break up oil by forming micelles which makes the surrounding area polar until the solution is uniform sufactants
solvent-solute interactions much be stronger than the solvent-solvent and solute-solute interactions conditions for substances to mix
once a carbon chain exceeds ____, it is generally going to be nonpolar and harder to mix with polar substances such as water 6
the net force on the surface molecules is inward, and they cluster close together to minimize surface area; in other words they want to minimize interactions with air molecules above them surface tension
the resistance of a liquid to to flow; measured in the unit centipoise where 1 cP is the viscosity of water at 20 degrees Celsius viscosity
the ability of a liquid to flow against gravity up a tube capillary action
intermolecular forces between neighboring liquid molecules cohesive forces
intermolecular forces between the liquid molecules and the molecules of the surface of the tube adhesive forces
the shape formed by a liquid in a tube meniscus
the liquid molecules rise up the sides of the tube concave meniscus
the liquid molecules crowd around the interior to maximize their interactions convex meniscus

Leave a Reply

Your email address will not be published. Required fields are marked *