Basic Review Flashcards
Scientific Method
a method of investigation involving observation and theory to test scientific hypotheses
Law of Conservation of Mass
matter can’t be created nor destroyed
Mass
a measure of resistance of an object to a change in its state of motion
Weight
amount of gravitational force exerted on an object
Celsius to Kelvin
Tk=Tc+273
Matter
anything occupying space and with mass
Law of Definite Proportion
a given compound always has exactly the same proportion of elements by mass
Law of Multiple Proportions
when two elements form a series of compounds, the ratios of the masses of the second element that combine with 1g of the first element can always be reduced to whole numbers
Radioactivity
Spontaneous emission of radiation
Types of Radiation
Alpha Particles- 2+ charge Beta Particles- high-speed electrons
Isotopes
atoms with the same number of protons but a different number of neutrons Gamma Ray- high-energy light
Chemical Bonds
Force that holds atoms together
Naming Binary Ionic Compounds
1.Cation first, anion second
Naming Polyatomic Ions
1.The ion with the smaller number of O2 ends in -ite
Finding Empirical Formulas
1.Calculate moles of each atom in molecule
Percent Yield
Actual Yield/Theoretical Yield*100%
Net Ionic Equation
only contains ions that change in reaction
Acids
substances that form H+ when dissolved in water; proton donors
Bases
Substances that form OH- when dissolved in water; proton acceptors
Molarity
moles of solute/volume of soln(L)
1atm=?mmHg/Torr
760mmHg/Torr
1atm=?Pa
101,325 Pa
Ideal Gas Law
PV=nRT P=atm V=L n=mol R=.0826Latm/Kmol T=K
STP
0°C and 1 atm
Dalton’s Law of Partial Pressures
Ptotal=P1+P2+P3+…
Kinetic Molecular Theory
-FOR IDEAL GASES!!!
Decrease Volume and Increase Temperature
Increase Pressure
Increase Temperature
Increase Volume
Root Mean Square Velocity
u(rms)=(3RT/M)^1/2 R=8.31J/Kmol
Joule
SI unit of energy; Kg*m^2/s^2
Molality
mol of solute/kg of solvent
Normality
(N) number of equivalents per liter of solution
Enthalpy of Solution
▲Hsoln=▲H1+▲H2+▲H3+…
Chemical Kinetics
studies the rate at which a chemical process occurs and sheds light on its reaction mechanism
Zero-Order Rate Law
r=k
First-Order Rate Law
r=k[A]
Second-Order Rate Law
r=k[A]^2
Zero-Order Half Life
[A]0/2k
First-Order Half Life
.69/k
Second-Order Half Life
1/([A]0*k)
Integrated Rate Law
expresses how the concentrations depend on time
Overall Reaction Order
n+m (these are orders of reactants)
Integrated First-Order Rate Law
ln[A]=-kt + ln[A]0 -linear form
Integrated Second-Order Rate Law
1/[A]=kt + 1/[A]0
Integrated Zero-Order Rate Law
[A]=-kt + [A]0
c=
λv
Speed of light
c=2.9979*10^8 m/s
Theory of Relativity
E=mc^2
Quantum Model
electrons in a hydrogen atom move around the nucleus only in circular orbits
Quantum Mechanical Model
involves quantum numbers
Quantum Numbers
describe various properties of one orbital
Principal Quantum Number
(n) has values 1,2,3,…; tells energy levels
Angular Momentum Quantum Number
(ℓ), has values from 0 to (n-1); tells shape of atomic orbitals
ℓ=0
s orbital
ℓ=1
p orbital
ℓ=2
d orbital
ℓ=3
f orbital
ℓ=4
g orbital
Magnetic Quantum Number
(mℓ) has values from -ℓ to ℓ, including zero; tells orientation of the orbital relative to other orbitals
Nodes
where there are no electrons
Electron Spin Quantum Number
(msubs) can only be +1/2 or -1/2
Pauli Exclusion Principle
in a given atom no two electrons can have the same set of four quantum numbers
Aufbau Principle
as protons are added to the nucleus, electrons are similarly added
Hund’s Rule
the lowest energy configuration for an atom is the one having the max number of unpaired electrons allowed by the Pauli principle in a set of degenerate orbitals
Equilibrium Expression
K=[C]^l[D]^m/[A]^j[B]^k; products/reactants; solids don’t count
Equilibrium constant
K
Reaction Quotient
(Q) does the same as equilibrium expression, except it uses initial concentrations
Q=K
at equilibrium (Q?K)
Q>K
shift to left (Q?K)
Q
shift to right (Q?K)
Le Chatelier’s Principle
if a change is imposed on a system at equilibrium, the position of the equilibrium will shift in a direction that tends to reduce that change
Acid Dissociation Constant
Ka=[products]^m/[reactants]^n
pH=
Err:509
Buffered Solution
a solution that resists a change in its pH
Solubility Product
(Ksp) an equilibrium expression
Law of Conservation of Energy
energy can’t be created nor destroyed
Heat
the transfer of energy between two objects due to temperature difference
Work
force acting over distance
▲E
q+w
Specific Heat Capacity
J/°Cg or J/Kg
Molar Heat Capacity
J/°Cmol or J/Kmol
Hess’s Law
in going from a particular set of reactants to a particular set of products, the change in enthalpy is the same whether the reaction takes place in one step or in a series of steps
▲H°reaction
Σn▲H°(products)-Σn▲H°(reactants)
Entropy
(S) the driving force for a spontaneous is an increase in entropy of the universe
▲Suniv
▲Ssys+▲Ssurr
▲Ssurr
-▲H/T
▲G
▲H-T▲S
▲G°
▲H°-T▲S°
G
G°+RTln(Q) R=8.31
w(max)
Err:501
Galvanic Cell
a device in which chemical energy is changed to electrical energy
Anode
where oxidation occurs
Cathode
where reduction occurs
Cell Potential
(Ecell) driving force of the electrons
Volt
unit of electrical potential; J/C
Faraday
96,485 C/mol e-
▲G
-nFE E=cell potential
Ampere
(A), C/s
Bond Energy
energy required to break a bond
Polar Covalent Bond
bond in which atoms aren’t so different that electrons are completely transferred but are different enough that unequal sharing occurs
Electronegativity
ability of an atom in a molecule to attract shared electrons to itself
Dipole Moment
a molecule having a center of positive charge and a center of negative charge
▲H
Σ(bonds broken)-Σ(bonds formed)
Lone Pair
pairs of electrons localized on an atom
Bonding Pairs
electron pairs found in the space between the atoms
Resonance
when more than one valid Lewis structure can be written for a particular molecule; represented by double-headed arrows
Formal Charge
(# of valence e- on free atom) - (# of valence e- assigned to atom in molecule)
Valence Electrons(assigned)
(# of lone pair e-)+1/2(# of shared e-)
Steps to VSEPR Model
- Draw the Lewis Structure
Linear
180°, sp
Trigonal Planar
120°, sp^2
Tetrahedral
109.5°, sp^3
Trigonal Bipyramidal
90°&120°, dsp^3
Octahedral
90°, d^2sp^3
Hybridization
the mixing of native atomic orbitals to form special orbitals for bonding
Sigma Bond
the line running between the atoms
Pi Bond
occupies the space above and below a sigma bond
Molecular Orbitals (MOs)
similar to atomic orbitals, except between molecules
Antibonding Molecular Orbital
higher in energy than the atomic orbitals of which it is composed
Bond Order
bonding e- - # antibonding e-/2
Coordination Compound
consists of a complex ion, a transition metal with attached ligands, and counterions
Counterions
anions or cations as needed to produce a compound with non net charge
Ligand
a neutral molecule/ion having a lone e- pair that can be used to form a bond to a metal ion
London Dispersion Forces
the intermolecular attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles
+ Delta G
Thermodynamically unfavorable (non-spontaneous)
- Delta G
Thermodynamically favorable (spontaneous)
- Delta H
Exothermic, more energy released by bonds forming than absorbed by bonds breaking
+ Delta H
Endothermic, more energy absorbed by bonds breaking than released by bonds forming
+ Delta S
Increase in entropy, more disorder on right side than left side
- Delta S
decrease in entropy, more disorder on left side than right side
Large eq. constant K
Forward reaction favored, greater rt. side than left side concentration/pressures, - delta G
Small eq. constant K
backward reaction favored, greater left side than right side concentration/pressure, + delta G
Acids with a large Ka
Stronger (more ionizing, more hydrogens free to roam)
Bases with small Kb
Weaker (less ionizing, more hydroxides “stuck” to cation)
Coefficients ARE exponents for..
Equilibrium expression
Coefficients MAY be exponents for..
Rate law
Boyle’s law
Pressure and volume of gases are inversely related at constant temperature.
Pb (2+) + Ni → Ni (2+) + Pb…..which is cathode?
Pb(2+)/Pb
How do you solve a calorimetry problem?
Q (lost)= Q (gained)
Which is anode, which is cathode?
More positive (as on reduction potential table) is the anode
What is the combined gas law?
(P1V1/)/T1=(P2V2)/T2
What is half life constant?
1st order reactions!!
What graph represents a 1st order reaction?
ln[A] versus time is linear
What is the titration equation?
MaVana=MbVbnb
What is electrical force?
Force= (Kq1q2)/r^2
What does Kp=Kc?
Kp=Kc(RT)^Δn (of gas…right compared to left)
What is entropy?
amount of disorder in a system (lower number means less disorder)
When is ΔG negative (thermodynamically favorable)?
ALWAYS when +ΔS and -ΔH
How is absorbance related to % transmittance?
A=-log(%T/100)
When does K=Q?
system is at equilibrium and reaction does not shift to left or right
What happens to bonds in an exothermic reaction?
They are formed
What happens to bonds in an endothermic reaction?
They are broken.
What is vapor pressure?
the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases at a given temperature in a closed system.
When does pH=pKa?
half equivalence point
When can dispersion forces in one substance be greater than hydrogen bond forces in another substance?
if there is a temporary dipole moment
electronegativity
how much the nucleus pulls on the shared electrons
critical point
When a substance has reached an irreversible state of matter
larger k favors the…
right side stuff, or products
What graph represents a zero order reaction?
[A] vs. time if it is linear
What graph represents a second order reaction?
1/[A] vs. time if it is linear
buffer
weak acid with its conjugate base or weak base with its conjugate acid
Absorbance
A=(absorbativity)(path length in m)(concentration in M)
vapor pressure
keeps a substance from becoming a gas, increases with pressure
Hydrogen bonds
Oxygen, Nitrogen, Fluorine with
Hydrogen
Strong IMF
means a higher boiling point, harder to change phases, greater the difference in electronegativity means the stronger the attraction.
sublimation
change directly from solid to gas at low pressure
temperature
the average kinetic energy, the speed of particles
One of the few substances that expands in solid form
water
changes directly from gas to solid
deposition
weak acids
do not dissociate completely, does not release all its hydrogens, higher pKa, does not fully “break away”
To change a substance from solid to liquid or liquid to gas…
you’d need an increase in temperature or a decrease in pressure.
factors that affect rate
reaction type, temperature, pressure, surface area, & catalysts
Titration equation with acid/base
(#H+) m1v1=m2v2(#OH-)
REDOX
reduction: gains electrons
Atomic Radius & Ionization Energy & Electronegativity Trends
Atomic Radius: Increase↓, Decrease→ Ionization Energy: Decrease↓, Increase→
Electronegativity: same as Ionization Energy
Brønsted-Lowery Conjugate Acid/Base Pairs
Conjugate base = acid - one H⁺
Slowest step in multi-step reaction
slow rate step = rate determining
Beer’s Law
A= - log%T A=Absorbance
T=Transmittance in DECIMAL
Kw
Kw=1.0x10⁻¹⁴
What is the numerator and denominator in the K eq?
(right side stuff) raised to coefficients/left side stuff raised to coefficients
Effective charge on an electron
Number of protons in nucleus-number of electrons in lower energy levels.
What are the strong acids?
HCl, HBr, HI, HNO3, and first hydrogen ion on H2SO4
Covalent Network Solids
Diamond (Carbon), Graphite (Carbon), Sand (SiO₂)
