CST study cards Flashcards
Oxidation number for alkali metal
+1
Oxidation number for alkaline earth metal
+2
Oxidation number for group IIIA metals
+3
Oxidation number for hydrogen
+1
Oxidation number for fluorine
-1
Oxidation number for oxygen
-2
Oxidation number for halogens
-1
Oxidation number for Group VIA nonmetals
-2
Very active metals
Li, Na, K, Rb, Cs, Ca, Sr, Ba
React with H2O to produce H2
Active metals
Mg, Zn, Pb, Ni, Al, Ti, Cr, Fe, Cd, Sn, Co
React with acids to form H2, but not with H2O
Inactive metals
Ag, Au, Cu, Pt
DO NOT form H2 with acids; may react with concentrated oxidizing acids HNO3 and H2SO4 or aqu regia
Activity series for halogens
F2 > Cl2 > Br2 > I2
galvanic or voltaic cell
produces energy spontaneous redox reaction that creates a flow of electrons cathode (+) / reduction anode (-) / oxidation e- flows from anode to cathode
electrolytic cell
requires energy redox reaction is forced to occur by adding electric energy cathode (-) / reduction anode (+) / oxidation e- flows from anode to cathode
Equation for standard reduction potentials
Ecell = Ecathode - Eanode
Ecell = Ereduction - Eoxidation
negative E_cell = reaction is not thermodynamically favored as written
positive E_cell = reaction is thermodynamically favored as written
When given standard reduction potentials for two half reactions, how can you determine which one is most likely to be reduced in the full reaction?
The half reaction with the more positive standard reduction potential is more likely to be reduced.
Mercury (I)
formula and oxidation state
Hg_2^2+
Ammonium
formula and oxidation state
NH_4^+
Nitrite
formula and oxidation state
NO_2^-
Nitrate
formula and oxidation state
NO_3^-
Sulfite
formula and oxidation state
SO_3^2-
Sulfate
formula and oxidation state
SO_4^2-
Hydrogen sulfate (bisulfate) formula and oxidation state
HSO_4^-
Hydrogen phosphate
formula and oxidation state
HPO_4^2-
Dihydrogen phosphate
formula and oxidation state
H_2PO_4^-
Thiocyanate
formula and oxidation state
SCN^-
Carbonate
formula and oxidation state
CO_3^2-
Hydrogen carbonate (bicarbonate)\ formula and oxidation state
HCO_3^-
Hypochlorite
formula and oxidation state
ClO^-
Chlorite
formula and oxidation state
ClO_2^-
Chlorate
formula and oxidation state
ClO_3^-
Perchlorate
formula and oxidation state
ClO_4^-
Acetate
formula and oxidation state
C_2H_3O_2^- or CH_3COO^-
Permanganate
formula and oxidation state
MnO_4^-
Dichromate
formula and oxidation state
Cr_2O_7^2-
Chromate
formula and oxidation state
CrO_4^2-
Peroxide
formula and oxidation state
O_2^2-
Oxalate
formula and oxidation state
C_2O_4^2-
Metalloid elements
B - boron Si - silicon Ge - germanium As - arsenic Sb - antimony Te - tellurium
equation relating the speed of light to the wavelength and frequency
c = lambda * nu
speed of light = wavelength * frequency
equation relating the energy to the frequency of light
E = h * nu energy = planck's constant * frequency
definition of n (structure of the atom)
principal energy level
n = 1 is closest to the nucleus
definition of l (structure of the atom)
azimuthal quantum number (sublevel number) number of sublevels cannot be > n value cannot be > n-1 0 = s 1 = p 2 = d 3 = f
definition of m_l (structure of the atom)
magnetic quantum number (orbital number)
number of orbitals = 2l + 1
values = -l to l
indicates shape and orientation of orbital
Allotrope
element that has two or more distinct sets of chemical and physical properties
examples:
O_2 and O_3
C: graphite, diamond, bukminsterfullerene (C_60)
atomic radius trends in the periodic table
left to right - decreasing radius due to effective nuclear charge
top to bottom - increasing radius due to increased energy levels
effective nuclear charge
definition and trend in the periodic table
Total nuclear charge - non valence electrons
increases from left to right across a period
first ionization energy trends in the periodic table
usually decreases from top to bottom in a group
usually increases left to right in a period
binding energy equation
BE = energy of incoming photon - energy of emitted photoelectron
electron affinity
definition and trend in the periodic table
energy change that results from adding a electron to an atom
increases diagonally from bottom left to top right (F has the highest, Fr has the lowest)
electronegativity
definition and trend in the periodic table
describes the attraction of electrons by individual atoms
increases diagonally from bottom left to top right (F has the highest, Fr has the lowest)
combustion reaction definition
organic compounds that react with oxygen to form CO_2 and water
single-replacement reaction definition
element reacts with a compound to form a different element and a new compound
double-replacement reaction definition
two compounds react and the cation in one compound replaces the cation in the second compound
neutralization reaction definition
double replacement reaction in which one compound is an acid and one is a base
synthesis reaction definition
two or more elements react to form a compound
formation reaction defintion
synthesis reaction with the product having a coefficient of 1
addition reaction definition
a simple molecule or an element is added to another molecule to form a new molecule
decomposition reaction definition
a large molecule decomposes into its elements or into smaller molecules
thiosulfate
formula and oxidation state
S_2O_3^2-
soluble compounds based on cations
sodium
potassium alkali metals
ammonium
soluble compounds based on anions
nitrate (NO_3^-)
chemical driving forces for double-replacement reactions
- formation of water
- formation of a precipitate
- formation of a non-ionic (covalent) compound such as organic acids or gases
formal charge definition
formal charge = number of valence e- - [number of non-bonding e- + 1/2 number of bonding e-]
dipole moment equation
dipole moment = q * r
= difference in charge * distance between the two nuclei
Delta electronegativity
equation and meaning
delta electronegativity = (atom with largest electronegativity) - (atom with smallest electronegativity)
the greater the delta EN, the more polar the bond
if delta EN = 0, the bond is non-polar
delta EN > 1.7, bond is ionic
delta EN < 1.7, bond is polar covalent
bond order definition
bond order = total number of bonds for a given element/ # of atoms bonded to that element
bond strength calculation
bond energy is equal to bond strength
bond energy = h* nu
= Planck’s constant * frequency of vibration
sigma bonds
2 s orbitals
1 s and 1p orbital
2 p orbitals (1st p overlap)
only one per covalent bond
pi bonds
after 1 sigma bond is formed, subsequent bonds are pi bonds
2 p orbitals (sideways overlaps)
hybrid orbital description
combines sigma and p orbitals
sp3 - 1s and 3p orbitals combined to form identical bonds, tetrahedron
Boyle’s Law
P_1V_1 = P_2V_2 PV = constant
Charles’s Law
V_1/T_1 = V_2/T_2
absolute zero = x-intercept of this curve
V/T = constant
Guy-Lussac’s Law
P_1/T_1 = P_2/T_2 P/T = constant
Avogadro’s Principle
n_1/V_1 = n_2/V_2 n/V = constant
Kinetic Molecular Theory
- Gases consist of molecules or atoms in continuous motion.
- Collisions between these molecules and/or atoms in a gas are elastic.
- The volume occupied by the atoms and/or molecules in a gas are negligibly small.
- The attractive or replusive forces between the atoms and/or molecules in a gas are negligible.
- The average kinetic energy of a molecule or atom in a gas is directly proportional to the Kelvin temperature of the gas.
Pressure definition
P = F/A
Graham’s Law of effusion
sqrt (m1/m2) = v_rms2/v_rms1
square root of the mass of molecule 1 / the mass of molecule 2 = the rate of the diffusion of molecule 2 / the rater of the diffusion of molecule 1
Ideal gas law
PV = nRT
applies at low pressures and high temperatures (not near where gases condense)
Real gases
cooled and/or compressed
distance between particles decreased dramatically
Dalton’s law of partial pressures
when two gases are mixed together, the gas particles tend to act independently of each other
P_total = P_1 + P_1 + … were P stands for the partial pressure of each individual gas
London dispersion forces
dispersion forces / instantaneous dipoles / induced dipoles
weak attractive forces due to the momentary unequal distribution of electrons around an atom
the larger the molecule, the greater the London dispersion forces
dipole-dipole forces
attraction between the partial positive end of one dipole and the partial negative end of another dipolar molecule
hydrogen bonding
very strong dipole-dipole attractive forces observed exclusively in compounds that have an F, O, or N bonded directly to a hydrogen atom.
Strong electrolytes
HCl
HBr
HI
Weak acids
ethanoic acid / acetic acid (HC_2H_3O_2 or CH_3COOH) Methanoic acid (HCHO_2 or HCOOH) Propanoic acid (HC_3H_5O_2 or CH_3CH_2COOH) Benzoic acid (HC_7H_5O_2 or C_6H_5COOH) hypochlorous acid (HClO or HOCl) chlorous acid (HClO_2 or HOClO) Chloric acid (HClO_3, or HOClO_2) hydrosulfuric acid (H_2S) hydrofluoric acid (HF) phosphoric acid (H_3PO_4) water (H_2O)
Weak bases
related to ammonia
reaction quotient
Q
Use the equilibrium expression to calculate Q, compare Q to K_c to determine if the reaction is at equilibrium and if the forward or reverse reaction is favored.