Flashcards in Chemistry Deck (17):
elements with incomplete octet in their v.
hydrogen and helium (2)
elements with expanded octet in their v.
elements in period 3. Specifically,
A molecule with odd number electrons in v.
NO- nitric oxide with 11e
elements that will always follow octet rule
Na, Mg, C, N, O, F
The periodic trend that determines whether a covalent bond is polar
this compound form crystalline lattice in solid state
physical properties of ionic compound
high MP and high BP
soluble in water and polar solv.
In aq. or molten form are great conductor of electricity.
It's all because of the electrostatic forces. The elements are fully charged. The strongest intera-molecular force.
Naturally occurring diatomic elements
form number 7 on the periodic table (exc. H) and most ate in VII A:
H2, N2, O2, F2, I2, Br2 and Cl2
diff. in EN of polar cov. bonds
Anything greater than 1.7 will become ionic since one element will monopolize the entire e cloud.
How to determine which subshell fills first
Rule: lowest (n+l) fills first
When two equal numbers, then the one with the lowest n fills first.
Paulis exclusion rule: the orbital with lowest E fills first ( as distance from nucleus increases, E increases.)
The formula for the dipole moment of a bond or a molecule
D- displacement separating the two charges.
coordinated cov. bond
both of the shared electrons originated on the same atom
diff. guises of coordinate cov. bonds
lewis acid-base rxn
the diff between the ox and formal charge of a molecule
formal charge underestimates EN
oxidation number overestimates EN
Formal charge is 0 for C and O's
But oxidation # for O is -2 and +4 for C ( assumes 100% contribution of one element in taking up all the electron cloud).
and bond angle
PCl5 VSEPR and bond angle
trigonal bipyrimidal 90, 120, 180