final Flashcards
What are the two categories of mixtures? Difference between them?
Heterogeneous vs homogeneous. Heterogeneous mixtures are a physical combination that aren’t uniform, while homogenous mixtures are uniform.
What are the 6 phase changes and which phases do they indicate changes to/from?
Melting (s to l), Vaporizing/boiling (l to g), Subliming (s to g), Depositing (g to s), condensing (g to l), and freezing (l to s).
How can mixtures be separating?
Heterogeneous mixtures can be separated by centrifugation or filtration. Homogeneous mixture can be separated using differences in phase change temperatures (eg. distillation, evaporation)
Intensive vs. extensive properties?
Intensive properties stay the same no matter the amount of a substance (eg. density, hardness). Extensive properties depend on the amount of a substance present
(eg. mass, length, width, volume).
Precision vs accuracy.
Precision measures the consistency of results, and is related to the amount of random error in a measurement. Accuracy measures how close results are to the “correct” value, an dis related to the amount of systematic error.
What are the key points of John Dalton’s atomic theory?
Elements are made of atoms, and different elements are composed of different kinds of atoms (i.e. atomic structure dictates properties of different elements)
What were the results of the Cathode Ray Tube Experiment?
Electros are negatively charged (because they are attracted to a positively charged plate). The charge to mass ratio of an electron is 1.71 x 10ˆ11 (highly charged and very light)
What is the plum pudding atom model?
An atom is a spherical cloud of positive charge with negatively charged electrons.
What are alpha and beta particles?
Beta particles have the same charge to mass ratio and negative charge as electrons, making them high energy electors. Alpha particles have twice as much charge and opposite sign as an electron (+2), also 10^3 times heavier.
What kinds of particles were used in the gold foil experiment?
Alpha particles
What were the crucial outcomes of the gold foil experiment?
Most alpha particles passed directly through the gold foil, meaning most of the space in the gold empty was empty (at least of positive charge, which would have repelled alpha particles).
What atomic model came from the gold foil experiment. Describe the model.
The nuclear model: Positive charged all in the atomic nucleus (center), surrounded by a cloud of electrons (negatively charged)
Where are protons neutrons and electrons found in the atom?
Protons and neutrons found in nucleus, while electrons are outside the nucleus
What are orbitals?
The 3D areas of space that electrons can occupy around the nucleus.
How many electrons are in each orbitals?
Two electrons
How are orbital energies determined?
By their distance from the nucleus.
What does it mean for electron energies to be quantized?
Electrons can only exist at certain energy levels as determined by the orbitals
What are the quantum numbers?
Principal quantum number, angular momentum quantum number, magnetic quantum number, and spin quantum number
What does the principal qn indicate, and what are some “rules” for the principal quantum number?
“n” indicates relative size and energy of a group of orbitals in an atom. Must be a positive integer, orbitas with the same n are in the same shell, orbitals with the same n have same # of nodes, and total number of nodes in an orbital is n-1.
What does the angular momentum qn indicate, and what are some “rules” for the angular momentum quantum number?
“l” defines the shape of the orbital. Must be an integer with value from 0 to n-1. Value of l is number of angular nodes. Orbitals with same n and l as each other are in the same subshell. l=0 is s, l=1 is p, l=2 is d, l=3 is f.
What do we call orbitals with the same energy?
Degenerate
What does the magnetic qn indicate, and what are some “rules” for the magnetic quantum number?
“m1” Defines orientation of an orbital in the space around the nucleus. Must be an integer with value from -l to l. Also defines how many degenerate orbitals exist for each value of l (eg. if l=2, d orbital; 5 m1 values; 5 d orbitals for each shell n)
What does the spin magnetic qn indicate, and what are some “rules” for the spin magnetic quantum number?
Describes whether the magnetic field is spin up or down. ms can be -/+ 1/2. We can write an orbital as a box or line, and show that it contains a spin up/down electron, or both. Each orbital can have have one spin up/down electron, or both, but never two spin up electrons or two spin down electrons.
Does each electron in an atom have a unique set of quantum, numbers?
Yes
For same l value, higher n indicates _____ energy
higher
What is a node?
AN area where no electron can exist
Differences between radial and angular nodes.
Radial nodes are spherical, while angular nodes are planes or cones. Radial nodes never pass through the nucleus, while angular nodes always pass through the nucleus.
Increase in nodes means an _____ in the energy of the orbital
increase
How to determine number of angular nodes?
Same as l value
How are s and p orbitals shaped, respectively
spherical vs. dumbell-like/two lobed
What are the main groups on the periodic table?
Main group elements (alkali metals, alkaline earth metals, post transition metals, metalloids, nonmetals, halogens, noble gases) transition metals, and lanthanides & actinides
Which blocks of elements on the period table correspond to a orbital letter?
Alkali metals + alkaline earth metals (+ H and He) : S-block
Noble gases, Halogens, nonmetals, metalloids, post transition metals: P-block
Transition metals: D-block
Actinides and lanthanides: F-block
How do we write condensed electron configurations?
Take the last element on the row above (in brackets), and write the following orbital configurations. For example: Oxygen
original e configuration: 1sˆ2 2sˆ2 2pˆ4
condensed: [He]2sˆ2 2pˆ4
How do we write the valence electron configuration?
By writing only the electrons in the last shell. For main group elements only s and p orbitals are included in the valence electron configuration
What is an exchange interaction?
When electrons witht he same spin in degenerate energy orbitals can exchange with each other
What does the Econfig equation (42p) - aex mean?
There are four electrons at the 2p level, and energy (ex) is subtracted from the total energy of the configuration.
What are the exceptions to Hund’s rule?
Cr, Cu, Mo, Ag, and Au
Why are there exceptions to Hunds rule?
In those cases, putting the electron in the 3d orbital requires less (exhange) energy than putting it in the 4s energy level.
When forming anions and cations, where do the electrons get added/removed to/from?
For anions, electrons are added to the highest-n partly filled orbitals. For cations, electrons are removed from the highest n orbital
For D block elements, where are electrons removed from first?
The s orbital
What are isoelectronic elements?
Atoms and ions that have the same electron configuration
Atomic radium gets larger as we go ____ a group, and to the _____ across a period
Down, left
Anions are _____ than their parent atoms, while cations are ______ than their parent ions
Larger, smaller
What is ionization energy?
The amount of energy required to move 1 mole of electrons from one mole of an element in the gas phase
Ionization energy is always ____
positive
What does IE1 denote?
The first ionization energy; aka the amount of energy to remove the first electron from the neutral atom
First ionization energy increases as we go ____ a group, and to the _____ across a period
Up, right
What is electron affinity?
The amount of energy required to add 1 mole of electrons to an element in the gas phase
Electron affinity can be ____ or _____
Positive or negative
How do metals behave?
They conduct heat and electricity well, malleably, shiny
How do nonmetals behave?
They do not conduct heat or electricity well; mostly liquid or gas, some brittle solids
How do semimetals behave?
They behave physically like metals but chemically like nonmetals
What makes a compound ionic vs covalent vs. acid?
If it contains a metal, it is ionic. If not, it is covalent. If it doesn’t have a metal, but has H and a halogen/polyatomic ion, it is an acid
What are ionic compounds held together by?
Electrostatic charge (ionic bonds)
For ionic compounds, does the cation or anion come first?
The cation always comes first
Are molecular formulas for ionic compounds always empirical or molecular?
empirical
How are the anions in ionic compounds named?
either polyatomic ion name, or the root + ide
What are covalent compounds held together by?
Covalent bonds (shared pairs of electrons)
What are covalent compounds made up of?
Nonmetals and semimetals
What is listed first in covalent compounds?
The element with the lower group number (unless the elements are in the same group, then higher atomic #)
What are the ten prefixes for covalent compounds?
, Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca
How are covalent compounds named?
First element: prefix-element name (if prefix is mono, can drop the prefix)
Second element: Prefix-element root-ide
What makes up an acid?
H+ and a halogen ion or polyatomic ion
For acids with halogens, how are they named?
hydro-element root-ic acid
For acids with polyatomic anions, how are they named?
Root name of polyatomic anion + ic OR ous (ate–>ic; ite–> ous) + acid
What is a neutralization rxn?
When an acid and base react with one another to form water and salt.
What is the difference between molecular, overall ionic, and net ionic equations?
Molecular: Balanced Chemical Equation
Overall Ionic: Equation simplified into their ions
Net ionic: Equation without spectator ions
What is a precipitation rxn?
When dissolved substances react to form a solid.
What is a redox rxn?
A reaction that involves an electron transfer
Oxidant vs. Reductant
The oxidant oxidizes the reductant, while the reductant reduces the oxidant.
What are the rules for oxidation number?
Oxidation numbers of neutral molecules = 0
Atoms in pure elements always 0
In monatomic ions, ON is charge on ion
F is always 1-
H is always 1+, unless with a metal, in which case H is 1-
O is always 2-, unless H202, in which case O is 1-
Unless with O or F, Cl and Br are 1- in compounds
What determines if a displacement rxn will occur?
If a metal with.a higher activity series is combined with the cation of a metal that is lower on the activity series (higher must reduce lower)
barometer vs manometer
barometer measures atmospheric pressure above/below sea level, manometer measures fluid pressure
What are the 5 ideal gas properties?
Negligably small volume compared to volume they occupy, move randomly and constantly though volume, temperature and motion correlated, elastic collisions, no attraction or repulsion between ideal gas molecules.
What is the law of effusion (gases)
Ratio of effusion rate from gas a to be is the rms (root mean squared). As such the lighter gas will effuse faster
How/when does real gas behavior diverge from ideal gas behavior
When the volume taken up by the particle is no longer negligable in comparison to the total volume, and when the gases experience signficant IMFs.
Endo vs exothermic
Endo: heat flows into system, q and deltaH positive
Exo: heat flows out of system, q and deltaH negative
What do enthalpy of fusion and enthalpy of vaporization mean?
They refer to the amount of energy to go from solid to liquid or liquid to solid.
What is molar heat capacity
(c sub p ) the amount of energy needed to raise the temperature of 1 mol of a substance by 1 degree.
What is the most electronegative atom?
Fluorine
What is the formula for formal charge?
valence elecctrons - non bonding electrons - bonds.
What are equivalent resonant structures?
Structures that have the same energy
What are major/minor resonance structures?
Structures that contribute more or less to the real structure (based on energy/stability)
How can we determine which resonant structure is lower in energy?
0 formal charge = higher stability. If formal charges present, whichever structure has negative charge on the most negative charge is more stable.
What is bond order?
Number of bonds between two atoms
What are the exceptions to the octet rule?
H, He, Li, and Be follow the duet rule.
What determines bond length?
Larger elements lead to longer. bonds, and higher bond order leads to shorter bond
What is bond dissociation energy?
Energy required to break bonds.
What is the formula for steric number?
Bonded atoms + lone pairs
What are the electron pair geometries for each steric number?
2 - linear
3- trigonal planar/bent
4- tetrahedral/trigonal pyramidal/bent
5-trigonal bipyramidal /seesaw/t-shaped/linear
6-octahedral/square pyramidal/square planar
What are the bond angles for each electron geometry
Linear: 180
Trigonal planar/bent: 120/<120
Tetrahedral/trig planar/bent: 109.5/<109.5/«109
Trig bipyr/seesaw/T-shape/linear:90-120/<90-<120/<90/180
octa/square pyr/square plan: 90-90/<90-<90/90
In what situation will a molecule have optical isomers?
Tetrahedral carbon atoms with four different substituents will have optical isomers (which will be chiral molecules).
What are the types of IMFs from weakest to strongest?
Dispersion forces, Dipole-dipole, hydrogen bonds, ion dipole
When does hydrogen bonding occur?
Hydrogen bonding occurs when a molecule contains N-H, F-H, and O-H
How do IMFs impact the vapor pressure of liquids?
Stronger IMFs mean lower vapor pressures
What is each part of the Clausius Clapeyron Equation?
Pvap is the pressure of vaporization, delta Hvap is enthalpy of vaporization, T is temperature (kelvin), R is the gas constant, and C is a constant.
What is each part of Henry’s laws?
Cgas is concentration of gas in a solvent (mol/L), kH is henry’s constant, and Pgas is partial pressure of gas above a liquid.
