general chem Flashcards
charge of proton
1.6 x 10^-19 C
atomic number
of protons
mass number
sum of protons + neutrons
13
C, which number is which
6
13 is mass number
6 is the atomic number
atomic mass = ________ number
mass
which is reported on periodic table? atomic mass or atomic weight
weight
1 proton = ___ amu = _________
one
amu = 1.66 x 10^-24 g
elements with varying mass numbers
isotopoes
weighted average of all isotopes
atomic weight
Avogadros number
6.06 x 10^23
Planck relation
E = hf
E = energy of quantum h = 6.626 x 10^-34 Js f = frequency
angular momentum of orbiting hydrogen equation
L = nh / 2π
n = principal quantum # h = 6.626 x 10^-34 Js
Bohr’s angular momentum equations says electric momentum changes
only in discrete amounts, with respect of principal quantum #
energy of electron equation
E = - 2.18 x 10^-18 (J/e-) / n^2
energy of an electron ______ (becomes _____ negative) as it moves away from nucleus
increases, less negative
EM energy of photons
E = hc / λ
c = 3.00 x 10^8 m/s h = 6.626 x 10^-34 Js
hydrogen emission lines if you go from any n down to 1
Lyman
hydrogen emission lines if you go from n= 3 or more down to 2
Balmer
hydrogen emission lines if you go from n=4 or more down to 3
Paschen
larger energy transitions = ______ wavelength
shorter
Bohr did not take into account
atoms with more than one electron
heisenberg uncertainty principle
it is impossible to determine the momentum and position of an electron simultaneously
if you wanna know position, it has to stop.
pauli exclusion principle
no two electrons in an atom can have the same set of quantum numbers (cant be in the same position/energy)
principal quantum number (n)
any positive #, gives the shell number
max # of electrons within a shell
= 2n^2
azimuthal quantum number (l)
0 to (n-1) shape and # of sub shells within a shell
spectroscopic notation of azimuthal quantum numbers
Sam Please Dont Fail l = 0 = s l = 1 = p l = 2 = d l = 3 = f
max # of electrons within a subshell
4l + 2
magnetic quantum number (ml)
-l to +l
particular orbital within a subshell the electron may be found
shapes of orbitals
s = spherical
p = dumbbell (x, y, z)
d and f don’t need to know
max # of electrons
2n^2
max # of electrons in orbital
2
spin quantum number (ms)
+1/2 or -1/2
2p^4, what does this mean
n = 2 l = 1 # of electrons in subshell = 4
n + l rule
when asked which will fill first, do n + l
5d = 5 + 2 = 7 6s = 6 + 0 = 6
when doing electron configuration for cation, what do you do?
start with neutral atom
remove from highest n value
if tied, remove from highest l value
Hund’s rule
orbitals are filled up before adding a second electron
two common exceptions to electron configuration
chromium and copper
paramagnetic
have unpaired electrons, will orient spins to be weakly attracted to magnetic field
diamagnetic
have paired electrons, repel magnetic field
effective nuclear charge
pull between valence e- and nucleus
effective charge trend
increases to right
constant in group
more inner shells causes effective charge to
become constant, even though there are more protons, the separation is canceled by inner shells
inner shells =
principal quantum number
atomic radius trend
decrease to right
atomic radius increases down
alkali _____ dense than other metals
less
incomplete octet
hydrogen (2), helium (2), lithium (2)
beryllium (4) and boron (6)
expanded octet
period 3 or more
ex: phosphorous, sulfur, chlorine
bond between opposite charges
ionic bond
what shape do ionic bonds form
lattice structures
covalent bonding
shared e- between two similar charged ions (usually nonmetals)
non polar bond
electron in covalent bond shared equally
polar bond
electron in covalent bond shared uneqally
coordinate covalent
only one ion giving both electrons in covalent bond
bond structure of covalent bonds
individually bonded molecules
properties of ionic bonds (4)
- high melting and boiling point
- dissolve in polar solvents
- good conductors when molten
- form crystalline lattice structures to minimize repulsions
properties of covalent bonds (2)
- low melting and boiling points
2. poor conductors of electricity
EN difference < 0.5 =
non polar bond
to be polar covalent, what is difference in EN
0.5 - 1.7
dipole moment equation
p = qd
q = charge, d = displacement
formal charge
Valence electrons - dots - sticks
formal change _______ EN
underestimates, you assume electrons are shared
oxidation number ________ EN
overestimates, you give all e- to more EN atom
electronic geometry
all bonds
molecular geometry
only bonding (no LP)
parallel orbits =
pi bond
head to head orbitals =
sigma bond
three types of intermolecular forces
- LDF
- dipole dipole
- hydrogen
dispersion forces caused by
dipoles changing and shifting fast
when are DD interactions absent
gases, not close enough
what causes DD interactions
polar molecules aligning to opposite charge of a nearby molecule
when is H able to form hydrogen bonds
when bound to N, O, F
what does H attract in hydrogen bonds
negative charge on N O F
equivalent weight
a mass that provides one mole of whatever you need
= molar mass / n (n= # particles of interest)
if they give you an amount produced, what equation do you use to find the equivalents
mass of compound / gram equivalent weight (mass collected)
molarity =
normality / n (n=# of thing produced)
Normality units
equivalents / L
law of constant composition
any compound will contain the same ratio of elements
ex: H2O will always have 2x H than O
empirical formula
simplest whole # ratio of elements
molecular formula
exact # of atoms for each element
percent composition
% of a compound made up by a given element
percent composition equation
mass of element / mass of compound x 100
A + B –>
compound reaction
C –> A + B
decomposition reaction
CH4 + 2O2 -> CO2 + 2H201
combustion reaction
what do you need for a combustion reaction (2)
- a fuel (hydrocarbon)
2. an oxidant (oxygen)
single-displacement reaction
atom or ion is replaced by an atom or ion of another element
double-displacement reaction
elements from two different compounds swap places
acid + base -> salt + H20
neutralization reaction
theoretical yield
amount of product from the balanced equation
actual yield
amount of product you actually get
percent yield
actual / theoretical x 100
endings for oxyanions
ite = less ate = more
electrolytes
solutes that enable solutions to carry currents
collision theory
rate of reaction = # of CORRENT collisions per second
according to collision theory, rate =
Z x f
Z = collisions f = fraction of effective collisions
Arrhenius equation
k = Ae ^ (-Ea / RT)
A = frequency factor (s-1), amount of collisions Ea = activation energy
the exponent in the Arrhenius equation
if it becomes a smaller number, it becomes more positive
so, rate INCREASES
transition state
higher energy than reactants and products, cannot be isolated/theoretical
energy required to meet transition state =
activation energy
for most forward, irreversible equations, rate =
k{A}^x[B]^y
k = rate constant
x / y = orders of reaction
overall order of a reaction =
x + y
orders of reaction must be determined
experimentally, NOT STOICHIOMETRIC
zero-order reaction
formation of C does not depend on A or B
only way to change rate is by increasing K by changing temperature or adding catalyst
zero-order reaction graph
linear, slope opposite of k
first-order reaction
rate depends only on changing one reactant
first-order graph
nonlinear, depends on reactant concentration
on ln[A] vs. time, it is linear with a slope opposite of K
second-order reaction
rate depends on squaring one reactant or on both reactants
second-order on 1 /[A] vs time graph
linear, slope equals k
mixed-order reactions
rate orders that vary over time
broken-order
rate order is a fraction
equlibrium will have max _____ and min _____
max entropy
min Gibbs free energy
in equilibrium, exponents are =
to K
Q < K
equation not at equilibrium yet, more reactants
Q =. K
at equilibrium
Q > K
forward reaction has exceeded equlibirum, go back
If Keq is a negative, small value
[A] = 1
if you decrease pressure,
you move towards the side with less moles of gas
if you increase pressure
you move towards side where there is less moles of gas
if you increase volume,
you move towards the greatest number of moles of gas
kinetic pathway requires ____ energy to reach transition state but has ______ energy product
less energy higher energy (unstable)
thermodynamic pathway has a _____ energy transition state but produces a ______ energy product
higher lower energy (more stable)
fast products
kinetic, form faster
closed vs open system
closed cant exchange matter, open can
first law of thermodynamics
ΔU = Q - W
Q = heat added W = work done by system ΔU = change in internal energy of system
isothermal process
temperature = ΔU = constant = 0
Q = W
area under PV curve = Q and W
adiabatic process
no heat is exchanged
Q = O
Δ U = -W
work done ON system
isobaric process
pressure is common
PV curve has a flat line
isovolumetric process
volume constant, no work occurs
ΔU = Q W = 0
STP
T = 273 K P = 1 atm
standard conditions
T = 298 K P = 1 atm M = 1 M
sublimation
solid to gas
deposition
gas to solid
critical point
temperature and pressure when there is no distinction between phases, point to the far right (gas and liquid)
heat of vaporization past the critical point =
0
zeroth law of equilibrium
objects in thermal equilibrium when their temperatures are equal
state functions
TV HUGS
temp, volume
enthalpy, internal energy, Gibbs free, entropy
independent of path taken
process functions
Q and W
enthalpy = Q under
constant pressure
q =
mcΔT
heat capacity
mass x specific heat
when can we not use q = mcΔT
during a phase change
latent heat
q = mL
L = enthalpy of isothermal process
entropy equation
ΔS = Qrev / T
density
mass / V
at STP, 1 mole of gas = ____ L
22.4
Avogadros principle
as n increases, V increases
Boyle’s law
as P increases, V decreases
Charle’s Law
as V increases, T increases
Gay-Lussacs law
as P increases, T increases
Boyle
PV
Charles
TV
Gay Lussacs
TP
Dalton’s Law
pressure of container = sum of all partial pressures
mole fraaction
moles of gas A / total moles of gas
partial pressure equation
PA = (Xa)(PT)
vapor pressure
pressure exerted by evaporated participles above a liquis
solubility of gas increases with
partial pressure
[A] = Kh x PA
concentration dissolved = Henry’s constant x partial pressure
a in real gases will be
small for small/less polarizable gases
large for big/polarizable gases
it corrects for attraction
b in real gases will be
smaller in general, corrects for volume
molar solubility > ___ will dissolve
0.1 M
two main solubility rules
- all groups I metals are soluble
2. all nitrate salts are soluble (NO3-)
chelation
central cation bound to multiple places on the ligand (electron donor)
solubility constant ______ with temperature for gas
decreases
same molecular formula, different arrangement of bonds
structural isomer
same molecular formula, same connectivity of bonds
stereoisomers, differ in space
configurational isomers
can only change by breaking bonds
conformational isomers
differ in rotation around a single bond
which isomers are most similar
conformational
which isomers are most different
structural
staggered anti
two bigger groups are antiperiplanar (same plane, opposite sides)
gauge staggered
opposite of each other, but 60 degrees (not 180) apart
highest-energy state of Newman straight chain
total eclipse
totally eclipsed
two methyls overlap eachother
eclipsed
two methyls are 120 apart and overlap with hydrogens
