Chapter 2 Acids and Bases Flashcards
(21 cards)
Polar Covalent Bond
Where bonding electrons are more strongly by one atom than the other so the electron distribution is not symmetrical.
Electronegativity (EN)
The intrinsic ability of an atom to attract the shard electrons in a covalent bond.
Bonds between atoms with electron differences of less than .5, .5-2, and more than 2 are
Nonpolar covalent, polar covalent, Ionic
Inductive Effext
The shifting of electrons in a sigma bond in response to the electronegativity of nearby atoms.
Metals inductively donate
Nonmetals inductively withdraw
Dipole Moment
The magnitude of the charge Q at either end of the molecular dipole times the distance r between them.
u = Q x r
Measure of net molecular polarity
Formal Charge
The number of valence electrons in a neutral, isolated atom minus the number of electrons owned by that bonded atom in a molecule, which is the number of nonbonding electrons plus half of the bonding electrons.
Resonance Forms
Multiple individual line bond structures whose only difference is the placement of pi and nonbonding valence electrons.
Resonance Hybrid
A hybrid of all resonance forms that is the real structure of the molecule
Radical
A substance that contains a single unpaired electron in one of its orbitals, denoted by a dot
Bronsted Lowry acid
A substance that donates a hydrogen ion
Bronsted Lowry Base
A substance that accepts a hydrogen ion
Conjugate base and acid
The product that results when an acid loses a proton, or when a base gains a proton, respectively
Acidity Constant (Ka)
Ka = [H+][A-]/[HA]
pKa
How acid strengths are normally expressed
pKa = -log Ka
Organic Acids
Characterized by the presence of a positively polarized hydrogen atom bonded to an electronegative oxygen and those that contain a hydrogen atom bonded to a carbon next to a C=O bond
Organic Bases
Characterized by the presence of an atom with a lone pair of electrons that can bond to H+
Zwitterion Form
When amino acids undergo an internal acid-base reaction
Lewis Acid
Substance that accepts an electron pair
Lewis Base
Substance that donates an electron pair
Intermolecular forces, van der Waals forces, or noncovalent interactions
Variety of interactions between molecules that strongly affect molecular properties
Examples: dipole dipole forces, dispersion forces, hydrogen bonds
Hydrogen Bond
Attractive interaction between a hydrogen bonded to an electronegative O or N atom and an unshared electron pair on another O or N atom
