Chemistry

Acid
matter containing particles

undergo ‘acid dissociation’ in aqueous phase

produce hydromium ion and an appropriate strong/weak anion

Activation Energy
difference between the internal energy of the transition state for a given reaction/temperature and the average internal energy of the reaction molecules/temperature

E(a) = E(trans) – E(react)

Atom
Electrically neutral particle of matter comprising of the smallest possible amount of a given chemical element

Composed of equal numbers of protons/electrons and enough neutrons to effect the appropriate atomic mass

Chemical Equilibrium
condition of a chemical reaction mixture in which all reactant substances and all product substances are present together

The amount of each substance remaining constant overtime, and the overall free energy of the reaction mixture then being a minimum

The rate of the reaction in its forward direction being equal to the rate of the reaction in its reverse direction

Chemical Reaction
Process in which valence electrons in one/more substances (reactants) are re-distributed causing chemical bonds to break off the first, and then form on the second.

The presence of new chemical bonds being shown by giving the chemical formulas of one or more different substances (products)

Compound
Matter with invariable composition

Atoms/ions made of at least two different elements

Represented by a chemical formula

Covalent Compound
A compound that has the smallest particle possible amount of a molecule comprising 2+ atoms of 2+ non-metal elements

Sharing of valence electrons

Element
matter with invariable composition with the smallest amount being an atom (same protons)

Represented by chemical symbol (Upper case, lowercase)

Excess Reagent
reactant(s) that is left after chemical reaction – even if reaction proceeds from a given initial state all the way to completion
Formula Unit
Smallest possible amount of ionic compound comprising the simplest combination of cation/anion/ionic compound resulting in electrical neutrality
Hydrogen Bonding
Relatively strong inter-molecular bonding

Covalently bonded Hydrogen atom (positive charge) is attracted/interacts with negative atom (different molecule)

Ionic Compound
Pure matter having invariable composition

Comprised of an electrically neutral and simple combination of cation/anion forming a ‘formula unit’

Individual ions are: monatomic or polyatomic

Contain elements classified as metal and non-metal

Metal compounds = ionic compound

Limiting Reagent
Reactant in a chemical reaction that can be totally consumed by reaction, thereby ending the reaction as a process

Does not occur in real reactions, but rather chemical equilibrium

Mole
Amount of an element containing Avogrado’s Number of atoms or molecules (if covalent, formula units, ionic)
Molecule
Electrically neutral particle of matter comprised of: small amount of a covalent compound (bond via sharing of valence electrons) and 2+ electrically neutral atoms of 2+ elements
Monatomic Anion
Particle of matter with permanent negative electric charge and one atom of a non-metallic element gaining 1+ valence electrons in a chemical reaction

Formed

Monatomic Cation
Particle of matter with permanent positive electric charge and one atom of a metallic element losing 1+ valence electrons in a chemical reaction
Percent Yield
Measure of how far a reaction progresses from initial state to completion.

Expressed as percentage (<100%)

Polar Covalent Bond
Non-metal atoms unequally sharing pair of valence electrons

Atom with more electrons = partial negative charge
Atom with less electrons = partial positive charge

Polyatomic Ion
Particle of matter having a permanent electric charge (positive/negative) comprised of 2+ atoms with different elements covalently bonded by sharing valence electrons
Transition State
Theoretical high energy condition formed by:

collisions between molecules of reactant whose combined
E(internal) >= E(transition)

or

collision between molecules of product with combined E(internal), bond breaking/forming in transition state which provides pathway for reactants to interact and form products/reactants

Theoretical Yield
Amount of a given product of chemical reactive formed from initial state to completion (total consumption – maximum amount that can really be formed)
Strong Acid
Type of matter containing molecules that all undergo acid dissociation in aqueous phase