Chemistry Cumulative Final – Flashcards

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variables-
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quantities that have more that one value
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density=
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mass/volume
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Precision-
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how close the measurements in a series are to each other
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Accuracy-
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how close each measurement is to the actual value
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Aqueous Solutions:
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Solutions in which water is the solvent
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Precipitation:
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reactions in which insoluble substances are produced
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Acid-Base:
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reactions between acids and bases
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Oxidation-Reduction:
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reactions which result in a change in oxidation state
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Strong Electrolyte:
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Compounds that completely dissociate in to their ions in H2O
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Nonelectrolyte:
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Compounds that do not dissociate in to their ions in H2O.
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Most molecular compounds that dissolve in H2O are ____
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nonelectrolytes.
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Weak Electrolyte:
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A molecular substance in whose aqueous solution some of the molecules react with H2O to form ions, but where some do not
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Acids:
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A substance that ionizes in water to produce H+ ions.
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Bases:
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A substance that ionizes in water to produce OH- ions.
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Titration:
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one solution of known concentration is used to determine the concentration of another solution through a monitored reaction.
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Oxidation Number:
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The charge of an atom in a molecule or ion
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Each element in its pure form has the oxidation number of __
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0
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For monoatomic ions, the oxidation number is =
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to the charge of the ion.
Sodium ion Na+1, Calcium ion Ca+2
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fluorine always has an oxidation number of __
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-1.
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The oxidation number of O is ___
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-2
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Oxidation:
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Loss of Electrons, oxidation number increases
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Reduction:
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Gain of Electrons, oxidation number decreases (or is reduced)
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Oxidizing Agent:
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Compound responsible for the oxidation, but is itself reduced
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Reducing Agent:
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Compound responsible for the reduction, but is itself oxidized
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Combination reactions:
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two or more reactants form one product:
X + Y a Z
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Boyle’s Law:
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The Compressibility of Gases (when moles and temp are constant)
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Pressure is inversely proportional to ___
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volume
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As pressure increases, the volume ____
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decreases
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Boyle’s Law Equation
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P1V1= P2V2
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Charles Law:
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if a given quantity of gas is held at a constant pressure, its volume is directly proportional to the Kelvin temperature
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Volume is proportional to ____
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temperature
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As temperature increases, the volume ___
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increases
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Charles Law Equation
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V1/ T1 = V2/ T2
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General Gas Law or Combined Gas Law Equation
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P1 V1/ T1 = P2V2 / T2
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Avogadro’s Hypothesis:
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the volume of a gas at a given temperature and pressure is directly proportional to the amount of gas in moles.
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Standard molar volume:
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1 mol of gas occupies 22.414 L
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Standard Temperature and Pressure (STP) :
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0 oC or 273.15 K and 1atm
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The Ideal Gas Law Equation
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PV = nRT
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The Density of Gases Equation
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d= m/v= PM/RT
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Partial Pressure:
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the pressure of each gas in the mixture
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Dalton’s Law of Partial Pressure:
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the pressure of a mixture of ideal gases is the sum of the partial pressures of the different gases in the mixture.
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Effusion:
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the movement of a gas through a tiny opening in a container into another container where the pressure is very low.
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Graham’s Law:
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The rate of effusion of a gas is inversely proportional to the square root of the mass of its particles.
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The First Law of Thermodynamics
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The energy change for a system is the sum of the energy transferred as heat between the system and its surroundings and the energy transferred as work between the system and its surroundings.
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The First Law of Thermodynamics Equation
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?E= q + w
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?E=
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Change in energy content
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q =
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Energy transferred as heat to or from the system
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w =
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Energy transferred as work to or from the system
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Enthalpy:
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Is the thermodynamic function defined by H. It is equal to the amount of energy transferred as heat at a constant pressure.
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If ?H is negative, energy is transferred as heat from the system to the surroundings.
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Exothermic.
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If ?H is positive, energy is transferred as heat from the surroundings to the system.
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Endothermic.
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Specific Heat Capacity:
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The energy transferred as a heat that is required to raise the temperature of 1 grams of a substance by 1 kelvin (when heating or cooling)
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Specific Heat Capacity Equation
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q = C x m x ?T
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C =
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specific heat capacity, units in J/g*K
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m =
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mass of the substance
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?T =
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change in temperature
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Thermal Equilibrium:
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When two objects which were once at different temperatures, reach the same temperature
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Calorimetry:
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The method by which the energy evolved or required as heat in a chemical of physical process is measured.
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Calorimetry Equations
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qr + qsolution = 0
qsolution = Csolution x msolution x ?T
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Standard Molar Enthalpies of Formation ?fHo :
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The enthalpy change for the formation of 1 mol of a compound directly from its component elements in their standard states.
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Standard Molar Enthalpies of Formation ?fHo Equation
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?rHo= ? ?fHo(products) - ? ?fHo(reactants)
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Electromagnetic Radiation:
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Characterized by wavelength and frequency and includes light, microwaves, television and radio signals x-rays, and other forms of radiation
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Plank:
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Assumed that the EMR emitted was caused by vibrating atoms called oscilators. And if each oscilator had a frequency, and the emitted radiation had a certain energy, the following eqn could be written.
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Plank's Equations
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E= nh?
E= h?
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Plank's Constant
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h = 6.6260693 x 10 -34 J*s
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Einstein:
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Photoelectric Effect: electrons are ejected when light strikes the surface of a metal.
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The 4 visible lines in the spectrum of hydrogen are now known as the_____
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Balmer series.
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If n = 3 the wavelength of the ___ line in the Hydrogen spectrum is obtained
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red
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If n = 4 the wavelength of the ____ line is obtained
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green
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If n = 5 and 6 the wavelength of the ___ lines are obtained
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blue
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deBroglie:
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Proposed that matter which was normally considered a particle, could also exhibit wave properties. Previously for light in the photoelectric effect.
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Bohr Model:
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That both the energy and the location for the electron in the hydrogen atom can be described accurately
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Heisenberg:
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Determined that for an object such as an electron in an atom, it is impossible to determine accurately both its position and its energy.
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Heisenberg Uncertainty Principle:
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any attempt to determine accurately either the location or the energy will leave the other uncertain.
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Schrodinger:
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Developed quantum mechanics or wave mechanics. Uses mathematical eqns of wave motion to generate wave functions which are used to describe a electrons in the atom.
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Paramagnetic:
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Elements or compounds that have unpaired spins and are attracted to magnets.
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Diamagnetic:
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Substances in which all the electrons are paired (with 2 electrons in each pair, having opposite spins) experience a slight repulsion when subjected to a magnet
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Pauli Exlusion Principle:
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No two electrons can have the same set of quantum numbers. No more than two electrons can be in an atomic orbital.
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Aufbau Principle:
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The procedure in which electrons are assigned to orbitals.
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Ionization Energy:
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The energy required to remove an electron from an atom in the gas phase.
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Electron Affinity:
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The energy change for a process in which an electron is acquired by the atom in the gas phase or “how bad an atom wants an electron.”
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Trends in Ion Sizes:
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The trends are the same down a periodic group as for neutral atoms. Positive and negative ions increase in size, but they are much smaller and larger than the neutral atoms, respectively.
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Isoelectronic Ions:
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Ions that have the same number of electrons (but different number of protons). N-3, O-2, F-, Na+,and Mg+2
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Ionic bond:
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forms when one of more valence electrons is transferred from one atom to another. Produces a positive and negative ion. The “bond” is the attraction between the ions
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Covalent bond:
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forms by the sharing of valence electrons between atoms.
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Lattice Energy:
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D Holattice the enthalpy change that occurs when 1 mol of ionic solid separates into gaseous ions.
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Coulombs Law:
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electrostatic energy between two charges is directly proportional to the product of their magnitudes and inversely proportional to the distance between them.
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Electrostatic energy =
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(Cation charge x Anion charge) / (Cation radius + Anion radius)
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Bond Length:
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the distance between the nuclei of two bonded atoms
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Related to the atomic size and the order of the bond.
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Bond Length
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Bond Dissociation Enthalpy:
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the enthalpy change for breaking a bond in a molecule with the reactants and products in the gas phase
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Bond Dissociation Enthalpy Equation
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?rH= ??H(bonds broken)- ??H(bonds formed)
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Polar Covalent Bond:
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When the e- are shared unequally.
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If the difference between electronegativities is greater than 1.7, the bond is ____
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ionic
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If the difference between electronegativities is less than 1.7, the bond is ____
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polar covalent
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If the difference between electronegativities is 0.5 or less, the bond is _____
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covalent (nonpolar)
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Octet:
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An octet of e- surrounding an atom is regarded as a stable configuration.
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Bond pair:
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The e- involved in the covalent bond.
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Lone pair:
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The e- not involved in bonding also called nonbonding e-.
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Formal Charge:
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the charge on an atom in a molecule or polyatomic ion.
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Formal charge= group # of the atom- [ LPE + 1/2(BE)]
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group # of the atom- [ LPE + 1/2(BE)]
Group #= gives the number of valence e- for a particular atom
LPE= number of lone pair e-
BE= number of bonding e- around the atom
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Resonance structure:
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Alternative structures of the same molecule which have identical bonding patterns and equal energy.
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Resonance hybrid:
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The actual structure of the molecule is a composite of the equivalent resonance structures. In the hybrid, the bonds are between a single and double bond in length.
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Bond Order:
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the number of bonding e- pairs shared by two atoms in a molecule.
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Bond order=
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# of Shared pairs in all X-Y bonds / # of X-Y links in the molecule or ion
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Dipole/Induced Dipole Forces:
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polar molecules can induce a dipole in a molecules that do not have a permanent dipole.
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London dispersion forces are the only intermolecular forces that allow _____ molecules to interact
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non- polar
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