Comprehensive Vocabulary HL Chem Flashcards
(146 cards)
1
Q
What is a mole?
A
The amount of substance containing as many particles as there are atoms in 12 g of carbon-12.
2
Q
What is Avogadro’s constant?
A
The number of particles in one mole of a substance, approximately 6.022 × 10²³.
3
Q
Define molar mass.
A
The mass of one mole of a substance, measured in g/mol.
4
Q
What is an empirical formula?
A
The simplest whole-number ratio of atoms of each element in a compound.
5
Q
What does a molecular formula represent?
A
The actual number of atoms of each element in a molecule.
6
Q
What is stoichiometry?
A
The calculation of reactants and products in chemical reactions.
7
Q
Define limiting reactant.
A
The reactant that is completely consumed in a reaction, limiting the amount of product.
8
Q
What is theoretical yield?
A
The maximum amount of product that can be formed from a given amount of reactant.
9
Q
Define percentage yield.
A
The ratio of actual yield to theoretical yield, expressed as a percentage.
10
Q
What is concentration in chemistry?
A
The amount of solute per unit volume of solution, usually in mol/dm³.
11
Q
What is a standard solution?
A
A solution of known concentration used in titration.
12
Q
What is titration?
A
A technique for determining the concentration of a solution by reacting it with another of known concentration.
13
Q
Define atomic mass unit (amu).
A
A unit of mass equal to 1/12 the mass of a carbon-12 atom.
14
Q
What is atomic number (Z)?
A
The number of protons in an atom’s nucleus.
15
Q
Define mass number (A).
A
The total number of protons and neutrons in an atom’s nucleus.
16
Q
What is an isotope?
A
Atoms of the same element with different numbers of neutrons.
17
Q
Define relative atomic mass (Ar).
A
The weighted average mass of an atom compared to 1/12 of the mass of carbon-12.
18
Q
What is electron configuration?
A
The arrangement of electrons in an atom’s orbitals.
19
Q
What does the Aufbau principle state?
A
Electrons fill orbitals from lowest to highest energy levels.
20
Q
What is Hund’s rule?
A
Electrons occupy orbitals singly before pairing.
21
Q
Define the Pauli exclusion principle.
A
No two electrons in an atom can have the same set of quantum numbers.
22
Q
What is first ionization energy?
A
The energy required to remove one mole of electrons from one mole of gaseous atoms.
23
Q
What is successive ionization energy?
A
The energy required to remove additional electrons after the first.
24
Q
What is a continuous spectrum?
A
A spectrum that contains all wavelengths of light.
25
Define line spectrum.
A spectrum showing only certain discrete wavelengths.
26
What are energy levels?
The fixed energies an electron can have in an atom.
27
What are sublevels in atomic structure?
The divisions within energy levels where electrons are found.
28
What is a period in the periodic table?
A horizontal row in the periodic table.
29
Define group in the periodic table.
A vertical column in the periodic table.
30
What is atomic radius?
The distance from the nucleus to the outermost electron shell.
31
What is ionic radius?
The size of an ion compared to its neutral atom.
32
Define electronegativity.
A measure of an atom’s ability to attract electrons in a bond.
33
What is ionization energy?
The energy required to remove an electron from an atom.
34
What is electron affinity?
The energy change when an atom gains an electron.
35
Define metallic character.
The tendency of an element to lose electrons and form positive ions.
36
What are alkali metals?
Group 1 elements, highly reactive with water.
37
What are halogens?
Group 17 elements, highly reactive nonmetals.
38
Define transition metals.
D-block elements with variable oxidation states.
39
What does amphoteric mean?
A substance that can act as both an acid and a base.
40
What is a ligand?
A molecule or ion that donates a pair of electrons to a metal ion in complex formation.
41
Define coordination number.
The number of ligand atoms bonded to a central metal ion.
42
What are d-block elements?
Elements in groups 3-12 with partially filled d-orbitals.
43
What is paramagnetism?
Attraction to a magnetic field due to unpaired electrons.
44
What is diamagnetism?
Weak repulsion from a magnetic field due to paired electrons.
45
Define ionic bond.
The electrostatic force between oppositely charged ions.
46
What is a covalent bond?
A bond formed by the sharing of electron pairs between atoms.
47
What is a polar covalent bond?
A covalent bond where electrons are shared unequally, creating dipoles.
48
Define nonpolar covalent bond.
A covalent bond with equal sharing of electrons.
49
What is a metallic bond?
The attraction between a lattice of metal cations and delocalized electrons.
50
What is a lattice structure?
A repeating arrangement of ions or atoms in a solid.
51
Define coordinate (dative) bond.
A covalent bond where both electrons are donated by one atom.
52
What is a Lewis structure?
A diagram showing the arrangement of valence electrons in a molecule.
53
What is resonance in chemistry?
When multiple valid Lewis structures exist for a molecule.
54
What does VSEPR theory predict?
Molecular shapes based on electron pair repulsion.
55
What is a bond angle?
The angle between two covalent bonds in a molecule.
56
Define bond length.
The distance between the nuclei of bonded atoms.
57
What are intermolecular forces?
Forces of attraction between molecules.
58
What are London dispersion forces?
Weak intermolecular forces caused by temporary dipoles.
59
What are dipole-dipole interactions?
Attractions between polar molecules.
60
What is hydrogen bonding?
A strong dipole-dipole force involving hydrogen bonded to N, O, or F.
61
Define hybridization.
The mixing of atomic orbitals to form new hybrid orbitals.
62
What is a sigma bond (σ bond)?
A single covalent bond formed by direct overlap of orbitals.
63
What is a pi bond (π bond)?
A covalent bond formed by the sideways overlap of p orbitals.
64
What is an exothermic reaction?
A reaction that releases heat energy.
65
Define endothermic reaction.
A reaction that absorbs heat energy.
66
What is enthalpy change (ΔH)?
The heat energy change in a reaction at constant pressure.
67
What is the standard enthalpy of formation?
The enthalpy change when one mole of a substance is formed from its elements under standard conditions.
68
Define standard enthalpy of combustion.
The enthalpy change when one mole of a substance is burned in oxygen under standard conditions.
69
What does Hess’s Law state?
The total enthalpy change of a reaction is the same regardless of the route taken.
70
What is bond enthalpy?
The energy required to break one mole of bonds in gaseous molecules.
71
What is specific heat capacity?
The energy needed to raise the temperature of 1 g of a substance by 1°C.
72
Define calorimetry.
The measurement of heat changes in chemical reactions.
73
What is lattice enthalpy?
The energy required to separate one mole of an ionic compound into its gaseous ions.
74
What is enthalpy of hydration?
The enthalpy change when one mole of gaseous ions dissolves in water.
75
Define enthalpy of solution.
The enthalpy change when one mole of a substance dissolves in a solvent.
76
What is entropy (S)?
A measure of disorder in a system.
77
What is Gibbs free energy (ΔG)?
A measure of spontaneity of a reaction, defined as ΔG = ΔH - TΔS.
78
What is the rate of reaction?
The change in concentration of reactants or products per unit time.
79
Define activation energy (Ea).
The minimum energy required for a reaction to occur.
80
What is a catalyst?
A substance that increases the rate of a reaction without being consumed.
81
What is a reaction mechanism?
The step-by-step sequence of elementary reactions by which a chemical change occurs.
82
What is the rate-determining step?
The slowest step in a reaction mechanism that determines the overall rate.
83
What does collision theory state?
Reactions occur when particles collide with sufficient energy and proper orientation.
84
What is the Maxwell-Boltzmann distribution?
A curve showing the distribution of kinetic energies among particles.
85
What is the Arrhenius equation?
A mathematical relationship that relates the rate constant to temperature and activation energy.
86
What is dynamic equilibrium?
A state in which the forward and reverse reactions occur at the same rate.
87
Define equilibrium constant (Kc).
A ratio of the concentrations of products to reactants at equilibrium.
88
What does Le Chatelier’s principle state?
A system at equilibrium will shift to counteract a change.
89
What is homogeneous equilibrium?
An equilibrium in which all reactants and products are in the same phase.
90
Define heterogeneous equilibrium.
An equilibrium involving reactants and products in different phases.
91
What is the reaction quotient (Q)?
A value that determines whether a system is at equilibrium or which direction it will shift.
92
What is a Brønsted-Lowry acid?
A substance that donates a proton (H⁺).
93
Define Brønsted-Lowry base.
A substance that accepts a proton (H⁺).
94
What is a Lewis acid?
A substance that accepts an electron pair.
95
Define Lewis base.
A substance that donates an electron pair.
96
What is a conjugate acid-base pair?
A pair of substances that differ by one proton.
97
What does pH measure?
The hydrogen ion concentration in a solution, defined as -log[H⁺].
98
What is a strong acid?
An acid that completely ionizes in solution.
99
Define weak acid.
An acid that partially ionizes in solution.
100
What is a strong base?
A base that completely dissociates in solution.
101
What is a weak base?
A base that partially dissociates in solution.
102
What is acid dissociation constant (Ka)?
A measure of the strength of an acid.
103
Define base dissociation constant (Kb).
A measure of the strength of a base.
104
What is a buffer solution?
A solution that resists changes in pH when small amounts of acid or base are added.
105
What is a titration curve?
A graph showing pH changes during a titration.
106
What is oxidation?
The loss of electrons by a substance.
107
What is reduction?
The gain of electrons by a substance.
108
Define oxidizing agent.
A substance that causes oxidation by gaining electrons.
109
What is a reducing agent?
A substance that causes reduction by losing electrons.
110
What is an electrochemical cell?
A device that converts chemical energy into electrical energy.
111
What is standard electrode potential (E°)?
The voltage of a half-cell under standard conditions.
112
What is a galvanic (voltaic) cell?
A device that generates electrical energy from a spontaneous redox reaction.
113
What is an electrolytic cell?
A device that uses electrical energy to drive a nonspontaneous reaction.
114
What are Faraday’s laws of electrolysis?
Laws that relate the amount of substance deposited at an electrode to the charge passed through the electrolyte.
115
What is a homologous series?
A family of organic compounds with the same functional group and general formula.
116
Define functional group.
A specific group of atoms responsible for the chemical properties of a compound.
117
What is an isomer?
Compounds with the same molecular formula but different structures.
118
What is structural isomerism?
Isomerism due to differences in the connectivity of atoms.
119
Define stereoisomerism.
Isomerism due to different spatial arrangements of atoms.
120
What are optical isomers?
Stereoisomers that are non-superimposable mirror images.
121
What is a chiral center?
A carbon atom bonded to four different groups, leading to optical isomerism.
122
What is a nucleophile?
A species that donates an electron pair to form a new bond.
123
Define electrophile.
A species that accepts an electron pair to form a new bond.
124
What is an addition reaction?
A reaction in which atoms are added to a molecule without removing any atoms.
125
What is a substitution reaction?
A reaction in which one atom or group is replaced by another.
126
What is an elimination reaction?
A reaction in which atoms or groups are removed from a molecule.
127
Define condensation reaction.
A reaction in which two molecules combine, releasing a small molecule (often water).
128
What is polymerization?
The process of joining small molecules (monomers) to form large molecules (polymers).
129
What is ligand field theory?
A model describing the interaction between ligands and d-orbitals in transition metal complexes.
130
What is crystal field splitting?
The splitting of d-orbitals in a ligand field.
131
What are biochemical pathways?
Series of chemical reactions in biological systems.
132
What are reaction mechanisms in organic chemistry?
The stepwise sequences by which organic reactions occur.
133
What are rate equations?
Mathematical expressions relating reaction rate to reactant concentration.
134
What is hybrid orbitals in organic reactions?
The role of sp, sp², and sp³ hybridization in bonding.
135
What are transition metal complexes?
Metal ions bonded to ligands, often with distinct colors and reactivity.
136
What is spectrophotometry?
A technique to measure light absorption in chemical analysis.
137
What is accuracy in measurements?
How close a measurement is to the true value.
138
Define precision.
How close repeated measurements are to each other.
139
What is a systematic error?
An error that occurs consistently in the same direction.
140
What is a random error?
An error that varies unpredictably in different measurements.
141
Define absolute uncertainty.
The uncertainty of a measurement expressed with its units.
142
What is percentage uncertainty?
The relative uncertainty of a measurement expressed as a percentage.
143
What are significant figures?
The number of meaningful digits in a measurement.
144
What is experimental yield?
The actual amount of product obtained in an experiment.
145
What is theoretical yield?
The maximum possible amount of product predicted by stoichiometry.
146
What is percentage error?
A measure of how far an experimental value is from the accepted value.
