Chem Final Flashcards
First law of thermodynamics
energy cannot be created or destroyed
Second law of thermodynamics
the entropy of the universe is increasing
Molarity
moles of solute/ L of solution
molality
moles of solute/ kg solvent
weight percent
(mass of compound x/ total mass) x 100% ( no units)
aufbau principle
order filled in (think diagonal)
pauli exclusion principal
no 2 electrons can have the same 4 quantum numbers
Hunds rule
fill all with spin up before doubling up
Pauling scores of fluorine, carbon, and hydrogen
F = 4.0, C = 2.5, H =2.1
Combustion
A combustion reaction always has oxygen as one reactant
Synthesis
A synthesis reaction is a chemical reaction where two reactants combine to create a new, more complex product.
A + B –> C
Decomposition
AB –> A + B
Double replacement
those in which two ionic compounds exchange their ions
single replacement
a reaction in which one element is substituted for another element in a compound.
precipitation
one in which dissolved substances react to form one (or more) solid products
Acid- Base
look for a chemical reaction where one reactant (the acid) donates a hydrogen ion (H+) to another reactant (the base), typically forming water (H2O) and a salt as products
redox
a chemical reaction that involves the transfer of electrons between two substances
Third law of thermodynamics
change in S = 0 at 0 Kelvin for perfect crystalline solid
(the entropy of a system approaches a constant value as the tempreature approches absolute zero)
omit solids and liquid when…
calculating q and k
Le Chatelier principle
if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to reestablish an equilibrium
Arrhenius Bronsted-Lowry
acid dissociates to produce hydrogen ions in water. A base produces hydroxide ions in water. In the Bronsted-Lowry theory, an acid is a proton donor. A base is a proton acceptor
JJ Thompson
Cathode Ray experiment, discovered the electron, particles in the charged tube bent towards positive charged side
Ernest Rutherford
gold foil experiment, fired particles at gold foil, some passed tyhrough other bounced off, conclusion that atoms have mass in the nucleus
formal charge
= (# of valence electrons) - ( # of lone electrons) - (# of bonds)
Heisenberg Uncertainty Principle
we cannot know the exact position and movement of an electron at any moment
probability density function
the square of the wave function represents the probability of locating an e in a given region of an atom
Fusion
melting –> solid to liquid
Sublimation
solid to gas
deposition
gas to solid
When determining IMF
1) ionic
2) polar
3) FON
none? –> london dispersion
molecular reaction
chemical species written as a whole compund of molecule
complete ionic reaction
compounds that can dissociate into ions will do so +aquaese phase compounds dissociate into their component ions
Net ionic reaction
cancel out spectator ions (appear in both reactant and product, present in reaction solution and do not participate in rxn)
molecular reaction
exact number of each atom
Empirical reaction
simplest ratio
6 oxidation rules
1) the oxidation number of an element = 0
2) oxidation # of an ion = ions charge
3) oxidation # of Oxygen in compounds = -2
4) oxidation number of Hydrogen in covalent compounds = +1
5) Oxidation of halogens = -1
6) sum of each elements oxidation # = overall charge of molecule
auto ionization of water
Kw at 25 C (Kw- 1 x 10^ -14)
Enthalpy
(H) total heat of a system ( can be calculated using Hess Law, calorimetry, or bond energies)
Entropy
(S) degree of disorder within a system ( can be calculated using products minus reactants formula or change in G formula if given G, H, and T)
Buffers are made of
a weak acid and a conjugate base
sigma bonds
of bonds
pi bonds
double bond (count as one) triple bond (count as two) # of those
Molecular rxn
normal equation
complete rxn
complete expanded reaction with ions dissociated (aquase state AND strong acids)
net ionic rxn
complete rxn
Q > K
shift left towards reactants
Q < K
shifts right towards products
Q = K
equilibrium
5% rule
The x term that we dropped must be less than 5%
of the number the assumption was made against
equivilance point
the point at which the amount of titrant added is exactly enough to neutralize the analyte
amphoteric
acts both as an acid and a base
photoelectron effect
phenomenon where electrically charged particles are released from or within materials when it absorbs electromagnetic radiation.
