Kaplan Flashcards
(143 cards)
1
Q
Entropy
A
The chaos or randomness of a system, often denoted by S
2
Q
Enthalpy
A
The total heat content of a system at a constant pressure, commonly denoted by H
3
Q
Endothermic Reaction
A
A reaction that proceeds with the net absorption of heat from the surroundings
4
Q
Empirical Formula
A
Chemical formula showing the smallest whole number ratio of atoms in a compound
5
Q
Electronegativity
A
A measure of an atom’s ability to pull electron density towards itself when involved in a chemical bond.
- Increases from left to right and from bottom to top on the periodic table
6
Q
Electron Affinity
A
the energy released when an atom or ion in the gaseous state gains an electron.
- Increases from left to right and from bottom to top on the periodic table
7
Q
Electrolytic Cell
A
An electrochemical cell that uses an external electric source to drive a non-spontaneous oxidation reduction reaction
8
Q
Electrolyte
A
An ion and water that is capable of conducting electricity in that solution
9
Q
Electrochemical Reaction
A
A chemical reaction that either is driven by or produces electricity
10
Q
Effusion
A
The movement of gas from 1 compartment to another through a small opening under pressure
11
Q
Effective Nuclear Charge
A
The resulting positive nuclear charge an outer electron senses after accounting for the shielding effect of inner core electrons (Zeff)
- Increases from left to right and from bottom to top on the periodic table
12
Q
Double- Displacement Reaction
A
A chemical reaction in which two different compounds exchange an atom or ion to form 2 new compounds
- Also called a metathesis reaction
13
Q
Disproportionation (Dismutation)
A
An oxidation reduction reaction in which the same species is both oxidized and reduced
14
Q
Dipole moment
A
The product of the magnitude of either partial charge and a dipole multiplied by the distance between the charges
15
Q
Diffusion
A
Passive dispersion of a gas or solute throughout a medium by means of random motion
16
Q
Diamagnetic
A
An atom or a substance that contains no unpaired electrons and is consequently repelled by a magnet
17
Q
Cathode
A
The electrode at which reduction occurs during a cell’s oxidation
reduction reaction
- Electrons flow towards it
18
Q
Chemical Kinetics
A
The study of reaction rates and the factors that affect them
19
Q
Concentration
A
The ratio of the amount of solute to the amount of solution
- Quantified by mole fraction, molarity, molality, or normality among other measures
20
Q
Conjugate acids and bases
A
a systematic pairing of a protonated species (acid) with its deprotonated form (conjugate base) or a deprotonated species (base) with its protonated form (conjugate acid)
21
Q
Decomposition reaction
A
a chemical reaction in which one substance breaks down into two substances
22
Q
Combination reaction
A
a reaction in which two or more reactants combine to form a product
23
Q
Avogadro’s principle
A
states that the number of moles of a gas present is proportional to its volume, assuming constant pressure and temperature
24
Q
Boyle’s Law
A
states that at a constant temperature, the volume of an ideal gas is inversely proportional to its pressure
25
Bronsted- Lowry definition
common definition of acids as proton donors and bases as proton acceptors
26
Buffer
a solution containing a weak acid or base coupled with its conjugate salt, acting to prevent changes to the solution's pH upon the addition of acidic or basic substances
27
Charles’s law
states that at a constant pressure, the volume of an ideal gas is directly proportional to its temperature
28
Closed system
a system that allows for the exchange of energy, but not matter, across its boundaries
29
Colligative properties
the properties of solutions-such as vapor pressure lowering, freezing point depression, boiling point elevation, and osmotic pressure- that are affected only by the number of solute particles dissolved and not by their chemical identities
30
Collision Theory of Chemical Kinetics
theory stating that the rate of a reaction is directly proportional to the number of collisions that take place between reactants per second
31
Common Ion Effect
states that the molar solubility of 1 salt is reduced when another salt, having a common ion, is brought into the same solution
32
Constant- Volume Calorimeter
an apparatus commonly referred to as a bomb calorimeter; used to measure the amount of heat absorbed or released during a reaction
33
Activation energy
the energy barrier that must be overcome for a reaction to proceed; often denoted by Ea
- measured in joules
34
Percent yield
a ratio of the actual mass of product yielded to the theoretical yield of product mass
35
Heat
a transfer of energy from a substance with a higher temperature to a substance with a lower temperature
36
Halogens
elements found in Group 17 of the periodic table
37
Half - Equivalence Point
the point in a titration at which exactly half the molar equivalence of reactant is consumed by the titrant being added
- pH is equal to the PKa of the titrand
38
Half-cell
an electrode immersed in an electrolytic solution that is the site of either oxidation or reduction in an electrochemical cell
39
Graham's Law
law stating that the rates at which two different gases effuse or diffuse are inversely proportional to the square root of their molar masses
40
Gibbs Free Energy
the energy of a system available to do work
41
Gay Lussac's law
states that at a constant volume, the pressure of an ideal gas is directly proportional to its temperature
42
Galvanic cell
an electrochemical cell powered by a spontaneous oxidation reduction reaction that produces an electric current
- also called a voltaic cell
43
Free Radical
an atom or molecule that has an unpaired electron in its outermost shell
44
Formal Charge
the charge assigned to an atom in a molecule or polyatomic ion, assuming even division of the electrons in a bond
- molecules containing atoms with lower formal charges tend to be more stable than those with higher formal charges
45
Faraday's constant
denoted by F; equals 9.65 x 10^4
46
Adiabatic process
a process in which no heat is transferred to or from the system by its surroundings
47
Exothermic
a reaction that proceeds with the net release of heat into the surroundings
48
Equivalence Point
the point in a titration at which an equimolar amount of titrant has been added to the unknown solution
49
Equilibrium constant
the ratio of the concentrations of the products to the concentrations of the reactants at the point of equilibrium, where each reactant and product in the expression is raised to the power of its stoichiometric coefficient; commonly denoted by Keq
50
Equilibrium
a dynamic point reached by reversible reaction in which the rate of the forward reaction is equal to the rate of the reverse reaction
- no net change in the concentrations of the products and reactants over time
51
Alkali metals
the highly reactive elements found in Group one of the periodic table, except hydrogen
52
Alkaline earth metals
elements found in Group 2 of the periodic table
53
Aqueous solution
a solution containing water as its solvent
54
Arrhenius definition
a definition of acids as producers of excess H plus and bases as producers of excess OH minus and aqueous solutions
55
Acid dissociation constant
an equilibrium expression used to measure acid strength, given by the ratio of the product of the products molar concentrations to the product of the reactants molar concentrations, with each term raised to the power of its stoichiometric coefficient; denoted Ka
56
Amphoteric
a species capable of reacting as either an acid or a base
57
Anode
the electrode where oxidation occurs during a cell's oxidation reduction reaction
- electrons flow from the anode
58
Atomic radius
the distance measured either between the nucleus and outermost electron of an Atom or by the separation of the two nuclei and a diatomic element
- decreases from left to right and from bottom to top on the periodic table
59
Noble gas
inert elements naturally existing in a gaseous state that comprise group 18 of the periodic table
60
neutralization reaction
a reaction in which an acid and a base are combined to form a salt
61
net ionic equation
a representation of a displacement reaction showing only the reactive species and omitting the spectator ions
62
Nernst equation
any equation used to determine a cell's electromotive force when conditions are not standard
63
molecular orbital
the region and a molecule where atomic orbitals overlap, resulting in either a stable low energy bonding orbital or an unstable high energy anti bonding orbital
64
molarity
concentration of a solution calculated by moles of solute per liters of solution
65
molar solubility
the molarity of a solute such that a solution is saturated
66
molar mass
the sum of all the masses present in one molecule of a molecular compound
67
molality
concentration of a solution calculated by moles of solute per kilograms of solvent
68
metals
elements that are characteristically electropositive, malleable, and ductile
- tend to be found on the left side of the periodic table
- lustrous, and have relatively low ionization energies and electron affinities
69
metalloids
elements that have properties between those of metals and non-metals
- B,Si, Ge, As, Sb, Te, Po, At
70
Limiting reagent
the reactant and a chemical equation that, given nonstoichiometric amounts, determines the amount of product that can form
- reactant that runs out first
71
Lewis definition
a definition of acids as electron pair acceptors and bases as electron pair donors
72
Le Chatelier’s principle
states that when a system in equilibrium is placed under one of several stressors, it will react in order to regain equilibrium
73
law of conservation of energy
law stating that energy cannot be created or destroyed but only transferred and transformed
74
kinetic molecular theory of gases
a series of assumptions used to account for the behavior of ideal gases. The theory describes gases as volume less particles in constant, random motion that exhibit no intermolecular attractions and undergo completely elastic collisions with each other and the walls of their container
75
Isovolumetric process
a process in which volume remains constant, and no net pressure volume work is done
76
isothermal process
a process in which temperature remains constant
77
isolated system
a system that can exchange neither energy nor matter with its surroundings
78
isoelectronic
two different elements that share the same electronic configurations
79
isobaric process
a process that occurs at a constant pressure
80
ionization energy
the amount of energy required to remove an electron from orbit about a gaseous atom into free space
- increases from left to right and from bottom to top on the periodic table
81
ion product
the product of the molar concentrations of dissociated ions in solution at any point in a dissociation reaction, where each ion is raised to the power of its stoichiometric coefficient
82
ion
a single particle or polyatomic species with an electric charge
83
indicator
a chemical species that changes color when undergoing dissociation
- used to signal the end point of a titration
84
ideal gas law
a unification of Boyle's law, Charles’s law, Gay- Lussac's law, and Avogadro’s principle into the formula that describes the behavior of ideal gases
85
ideal gas
a hypothetical gas containing particles with 0 volume and with no attractive intermolecular forces
86
hydrogen bonding
very strong intermolecular force where a hydrogen covalently bonded to an N, O, or F is attracted to another N, O, or F
87
Hund’s rule
states that electrons will first fill orbitals within a subshell unpaired and with parallel spins before being coupled with other electrons of opposite spins in the same orbital
88
Hess’s law
states that the enthalpy change of an overall reaction is equal to the sum of the standard heats of formation of the products minus the sum of the standard heats of formation of the reactants
89
Henry's law
states that the partial pressure of a gas dissolved in a solution is directly proportional to the partial pressure of this gas above the solution
90
Henderson Hasselbach equation
an equation commonly used in titration-based problems that relates the pH or pOH of a solution to the PKa and the ratio of the dissociated species
91
Heisenberg uncertainty principle
the quantum mechanical concept that we cannot measure the exact momentum and position of an orbiting electron simultaneously
92
Titrant
a solution of known concentration added in small volumes to a solution of unknown concentration to reach the equivalence point
93
theoretical yield
the expected amount of product yielded in a reaction according to the reactant stoichiometry
94
Titrand
a solution of unknown concentration to which small volumes of a solution of known concentration are added to reach the equivalence point
95
System
the part of the universe under consideration that is separated by some real or imaginary boundary from its surroundings
96
strong acid
an acid that will completely dissociate in aqueous solution
97
state function
a variable that depends only on the current state of the system, and not the path taken to get there
- pressure, density, temperature, volume, enthalpy, internal energy, Gibbs free energy, and entropy
98
standard temperature and pressure (STP)
273 Kelvin (0°C) and one atmosphere (760 mmHg)
99
spontaneous reaction
a reaction that will proceed or occur on its own without additional energy input from its surroundings
100
specific heat
the amount of heat required to raise 1g of a substance by 1°C
101
solvent
a medium, commonly a liquid, and to which a solute is dissolved to create a solution
102
solvation
the process of forming a cage like network of solvent molecules around a solute in a solution
103
Solution equilibrium
when a solute is dissolved and a solvent, it will dissociate until reaching an equilibrium point at which the rate of dissociation equals the rate of precipitation of the solute, regardless of any additional solute introduced into the mixture
104
Solute
a compound, commonly an ion, dissolved in a solvent to create a solution
105
water dissociation constant
an expression of the auto ionization of water into H+ and OH- at a certain temperature, given by the product of the ions molar concentrations
- Kw
106
VSEPR theory
the acronym for valence shell electron pair repulsion theory, which states that the three-dimensional molecular geometry about some central atom is determined by the electronic repulsions between its bonding and non bonding electron pairs
107
triple point
a point on a phase diagram at which a substance exists in equilibrium between all three phases
108
Valence electrons
the electrons occupying the outermost electron shell of an atom that participate in chemical bonds
109
transition state
a high energy complex in which old bonds are partially broken and new bonds are partially formed
110
transition elements
the elements found in the B groups of the periodic table
- contain partially filled d subshells
111
titration
an analytical procedure in which a solution of known concentration is slowly added to a solution of unknown concentration to the point of molar equivalency, thereby providing the concentration of the unknown solution
112
solubility product constant
the product of the molar concentration of dissociated ions in a saturated solution, where each iron is raised to the power of its stoichiometric coefficient; Ksp
113
solubility
a ratio that measures how much solute can dissolve in a solvent at a given temperature
114
single displacement reaction
a chemical reaction in which an atom or ion of one compound is replaced by another atom or ion
115
reversible reaction
a process that will proceed bidirectionally to form both product and reactant
116
resonance structures
alternate Lewis structures of the same molecule that show the delocalization of electrons within that molecule
117
reduction potential
a measure of the tendency of a species to be reduced, commonly used in identifying the anode and cathode of an electrochemical cell
118
reduction
a reaction in which a species gains electrons
119
reducing agent
a species that is oxidized in the process of reducing another species
120
Reaction rate
the measure of how quickly reactants are consumed and products are formed
121
reaction quotient
the ratio of the concentrations of the products to the concentrations of the reactants at any point during a reaction, where each reactant and product in the expression is raised to the power of its stoichiometric coefficient; Q
122
reaction order
the sum of the exponents in a rate law, where each exponent provides the reaction order with respect to its reactant
123
reaction mechanism
a play by play showing the individual steps of a reaction, including the formation and destruction of any reaction intermediates that may occur
124
Rate Law
An experimentally determined mathematical expression showing the rate of a reaction as a function of the concentrations of its reactants
125
Rate - Determining Step
The slowest step in a reaction mechanism; determines the overall rate of the reaction
126
Raoult's Law
States that the vapor pressure of a solvent is proportional to the mole fraction of the solvent in the solution
- Provides explanation for boiling point elevation
127
Process Function
A variable that depends on the path taken to get from one state to another
- Includes work and heat
128
Polar Covalent Bond
Type of covalent bond between atoms with different electronegativities that results in an unequal sharing of electron pairs, giving the bond partially positive and partially negative poles
129
Photon
A particle of light energy with a value equal to hf, where h is the Planck's constant and f is the frequency of radiation
130
Phase Diagram
A pressure-temperature plot showing the conditions under which a substance exists in pure phase or in equilibrium between different phases
131
pH
Scaled value used to measure the acidic strength of a solution
132
Percent Composition
The percentages of the elements making up a compound
133
Pauli Exclusion Principle
States that no 2 electrons in an atom can have the same set of 4 quantum number values
134
Partial Pressure
The pressure contribution of a single gas in a container holding a mixture of gases
135
Paramagnetic
An atom or a substance that contains unpaired electrons and is consequently attracted to a magnet
136
Oxidizing Agent
A species that is reduced in the process of oxidizing another species
137
Oxidation-reduction Half-Reaction
A hypothetical equation showing only the species that is oxidized ore reduced in a oxidation-reduction reaction and the correct number of electrons transferred between the species in the complete, balanced equation
138
Oxidation
A reaction in which a species loses electrons
139
Open System
A system that allows for the exchange of energy and matter across its boundaries
140
Octet Rule
A rule stating that atoms tend to react in order to form a complete octet of valence electron
141
Normality
Concentration of a solution calculated by gram equivalent weight of solute per liter of solution
142
Nonpolar Covalent Bond
A type of covalent bond between atoms with the same electronegativities, resulting in an even distribution of electron density along the bond
143
Nonmetal
Elements that characteristically high electronegativity, IE, and electron affinity
- Right side of periodic table
- poor conductors
