inorganic- Definitions Flashcards
(173 cards)
1
Q
What is the rate equation?
A
It relates the rate to the concentrations of the reactants multiplied by the rate constant, with each concentration raised to the power of the order with respect to that reactant.
2
Q
What is the rate of reaction?
A
A measure of how quickly a reactant is used up or a product is formed.
3
Q
What is a reaction mechanism?
A
A step-by-step sequence of the individual reactions that make up the overall reaction.
4
Q
What happens to the rate when the concentration of a second order reactant is doubled?
A
The rate will quadruple if all other conditions remain the same.
5
Q
What happens to the rate when the concentration of a zero order reactant is doubled?
A
There will be no impact on the rate if all other conditions remain the same.
6
Q
What is the Arrhenius equation?
A
k = Ae-Ea/RT where k is the rate constant, A is the pre-exponential factor, Ea is the activation energy, R is the gas constant, and T is the temperature.
7
Q
What is a clock reaction?
A
A reaction in which the time taken for an abrupt visible change to occur is measured, typically indicating the formation of the product.
8
Q
What is colorimetry?
A
A technique used to measure the amount of light absorbed by a solution to determine the rate of a reaction, often involving a calibration curve.
9
Q
What is a concentration-time graph?
A
A graph in which concentration is plotted on the y-axis and time on the x-axis, where the gradient equals the rate of reaction.
10
Q
What is continuous monitoring in rate experiments?
A
Continuous measurements are taken as the reaction progresses, allowing results to be plotted on a concentration-time graph.
11
Q
What happens to the rate when the concentration of a first order reactant is doubled?
A
The rate will double if all other conditions remain the same.
12
Q
What is the gradient in a graph?
A
The change in y divided by the change in x.
13
Q
What is half-life (t1/2)?
A
The time taken for the concentration of a reactant to half.
14
Q
What is the initial rate?
A
The rate of a reaction at t=0.
15
Q
What is the order of a reaction?
A
A number that relates the rate of a reaction to the concentrations of each reactant.
16
Q
What is the overall order of a reaction?
A
The sum of the orders with respect to each reactant.
17
Q
What is the rate constant (k)?
A
A constant value that relates the rate of a reaction at a given temperature to the concentrations of the reactants.
18
Q
How can the rate constant for a first order reaction be determined?
A
Using the relationship k = ln 2/t1/2.
19
Q
What is a rate-concentration graph?
A
A graph that has concentration plotted on the x-axis and rate on the y-axis.
20
Q
What is the rate-determining step?
A
The slowest step of a reaction.
21
Q
What is a catalyst?
A
A substance which speeds up the rate of a reaction without being used up.
22
Q
What is concentration?
A
The amount of a substance that is dissolved per unit volume of solution.
23
Q
What is an endothermic reaction?
A
A reaction that takes in energy from the surroundings, resulting in products with higher energy than the reactants.
24
Q
What is equilibrium?
A
The forward and reverse reactions of a process occur at exactly the same rate, meaning there is no overall change.
25
What is the equilibrium constant (K)?
A value that relates the amount of products and reactants at equilibrium in a reversible reaction at a specific temperature.
26
What factors affect the equilibrium constant (K)?
K is unaffected by pressure and the presence of a catalyst but is affected by temperature.
27
What is an exothermic reaction?
A reaction that gives out energy into the surroundings, resulting in reactants with higher energy than the products.
28
What is heterogeneous equilibrium?
An equilibrium reaction that involves substances in different states (solid, liquid, gaseous, or aqueous).
29
What is homogeneous equilibrium?
An equilibrium reaction that involves substances all in the same state (solid, liquid, gaseous, or aqueous).
30
What is Kc?
The equilibrium constant equal to the concentration of products raised to their stoichiometric coefficients divided by the concentration of reactants to the power of their stoichiometric coefficients.
31
32
What is Kp?
The equilibrium constant equal to the partial pressures of the products raised to the power of their stoichiometric coefficients divided by the partial pressures of the reactants raised to the power of their stoichiometric coefficients.
33
What is Mole Fraction (XA)?
XA = nA/n where XA is the mole fraction of A, nA is the number of moles of A and n is the total number of moles.
34
What is Partial Pressure (PA)?
The pressure that would be exerted by one gas in a mixture if it occupied the container alone. PA = PXA where PA is the partial pressure of A, P is the total pressure and XA is the mole fraction of A.
35
What is the Acid Dissociation Constant (Ka)?
The extent of acid dissociation. pKa = -log(Ka) and Ka = 10^(-pKa).
36
What is a Bronsted-Lowry Acid?
A proton donor.
37
What is a Bronsted-Lowry Base?
A proton acceptor.
38
What is a Buffer Solution?
A system that minimises pH change on addition of small amounts of an acid or base. A buffer solution can be formed from a weak acid and a salt of the weak acid or from excess weak acid and a strong alkali.
39
What is the Carbonic Acid-Hydrogencarbonate Buffer?
The buffer system present in blood plasma, used to maintain blood pH between 7.35 and 7.45.
40
What is a Conjugate Acid-Base Pair?
A pair of compounds that transform into each other by the transfer of a proton. Conjugate acid-base pairs are important in the formation of buffers to control pH.
41
What is a Dibasic Acid?
An acid that can donate 2 hydrogen atoms per molecule of the acid.
42
What is the End Point in titration?
The point during a titration when the indicator changes colour. A suitable indicator should change colour near the equivalence point.
43
What is the Equivalence Point in titration?
The point during a titration when the amount of acid is exactly equal to the amount of base (full neutralisation occurs).
44
What is an Indicator?
A weak acid that changes colour with changing pH due to an equilibrium shift between HA and A-. For an indicator to be suitable, its pH range must be within the vertical section of the titration curve.
45
What is an Ionic Equation?
A chemical equation that involves dissociated ions.
46
What is the Ionic Product of Water (Kw)?
The temperature dependent constant that represents the dissociation of water into H+ and OH-.
47
What is a Monobasic Acid?
An acid that can donate 1 hydrogen atom per molecule of acid.
48
What is pH?
A way of communicating the concentration of hydrogen ions. pH = -log[H+] and [H+] = 10^(-pH).
49
What is a pH Meter?
An instrument used to measure the pH of a solution.
50
What is the Strength of Acids and Bases?
A measure of the relative degree of dissociation of an acid or base (where strong means complete dissociation and weak means partial dissociation).
51
What is Titration?
A technique used to determine the amount of one solution of a known concentration required to completely react with a known volume of another solution of unknown concentration.
52
What are Titration Curves?
A graph which shows the change in pH over the course of a titration.
53
What is a Tribasic Acid?
An acid that can donate 3 hydrogen atoms per molecule of acid.
54
What is the Vertical Section in a titration curve?
The vertical part of a titration curve which contains the equivalence point for the titration.
55
What is the Born-Haber Cycle?
A cycle used to calculate the lattice enthalpy of an ionic compound using other enthalpy changes.
56
What does the Conservation of Energy state?
The total energy of an isolated system remains constant (energy cannot be lost or created).
57
What is Enthalpy (H)?
A value that represents the heat content of a system.
58
What is Enthalpy Change (ΔH)?
The change in the heat content of a system during a reaction.
59
What is Enthalpy Change of Atomisation (ΔH)?
The enthalpy change that takes place when one mole of gaseous atoms is formed from an element in its standard state.
60
What is Enthalpy Change of Formation (ΔfH)?
The enthalpy change that takes place when one mole of a compound is formed from its elements.
61
What is Enthalpy Change of Hydration (hydH)?
The enthalpy change that takes place when one mole of gaseous ions are dissolved in water (exothermic).
## Footnote
Increasing ionic charges and decreasing ionic radii make this value more negative as there would be greater attraction between the water molecules and the ions.
62
What is Enthalpy Change of Solution (solH)?
The enthalpy change that takes place when one mole of solute is dissolved.
63
What is First Electron Affinity?
The amount of energy released when one mole of electrons is added to one mole of gaseous atoms, forming one mole of 1- ions.
64
What is First Ionisation Energy?
The removal of one mole of electrons from one mole of gaseous atoms to form one mole of 1+ ions.
65
What is an Ionic Bond?
Electrostatic attraction between positive and negative ions.
66
What is a Giant Ionic Lattice?
A regular repeating structure made up of oppositely charged ions.
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What is Lattice Enthalpy (ΔLEH)?
The formation of one mole of an ionic lattice from gaseous ions.
## Footnote
Lattice enthalpy is used as a measure of the strength of ionic bonds in a giant lattice, with a more negative value meaning stronger bonds. Increasing ionic charges and decreasing ionic radii make this value more negative as there would be greater attraction between the ions.
68
What is Entropy (S)?
A measure of the dispersal of energy in a system. The greater the entropy, the more disordered the system.
## Footnote
The order of entropy for different states is solids < liquids < gases. Increasing the number of gaseous molecules in a reaction results in an increase in entropy.
69
What is Free Energy Change (∆G)?
The feasibility of a process depends on entropy change, temperature and enthalpy change. The equation for Gibbs free energy is: ∆G = ∆H - T∆S.
## Footnote
A process is spontaneous/ feasible when ∆G is negative. Gibbs free energy doesn’t consider kinetics.
70
What is Kinetics?
The part of chemistry relating to rates of reaction.
71
What is Cell Potential?
A measure of the potential difference between two half cells, calculated by combining 2 standard electrode potentials.
## Footnote
The calculated cell potential can be used to predict feasibility of a reaction, although this doesn’t consider concentration or kinetics.
72
What is an Electrochemical Cell?
Contains electrodes in an electrolyte and is used to generate current.
73
What is E.M.F.?
Electromotive force, measured in volts.
74
What is an Equimolar Solution?
A solution of ions in which there is an equal number of moles of each ion.
75
What is a Fuel Cell?
A type of cell that requires a constant supply of fuel and oxygen in order to generate a potential difference.
76
What is a Half Equation?
An equation which shows the number of electrons that are transferred during a reaction.
77
What is Oxidation?
The loss of electrons/ increase in oxidation number.
78
What is an Oxidation Number?
A number that represents the number of electrons lost or gained by an atom of an element.
## Footnote
A positive oxidation number indicates the loss of electrons.
79
What is an Oxidising Agent?
A substance that can oxidise another substance.
80
What is Redox?
A reaction in which oxidation of one element and reduction of another occurs.
81
What is Redox Titration?
A type of titration which involves the reduction of one substance and the oxidation of another.
## Footnote
The exact volume of titrant required to react with the analyte is determined using an indicator which shows the end point of the reaction.
82
What is a Reducing Agent?
A substance that can reduce another substance.
83
What is Reduction?
The gain of electrons/ decrease in oxidation number.
84
What is Standard Electrode (Redox) Potential (Eθ)?
The e.m.f. of a half cell compared with a standard hydrogen half cell.
## Footnote
This is measured under standard conditions (1 mol dm-3 solution concentrations, 298K and 1 atm).
85
What is a Storage Cell?
A type of cell that can store energy. Storage cells convert chemical energy into electrical energy by a reaction and they may be recharged by reversing the chemical reaction.
86
What is an Anion?
A negatively charged ion.
87
What is a Bidentate Ligand?
A substance that can form 2 dative covalent (coordinate) bonds with a metal ion/ metal.
## Footnote
E.g. NH2CH2CH2NH2 (‘en’).
88
What is a Catalyst?
A substance which increases the rate of a reaction without being used up.
89
What is a Cation?
A positively charged ion.
90
What is Cis-platin?
The cis-isomer of Pt(NH3)2Cl2, used as an anticancer drug.
## Footnote
Cis-platin binds to DNA, preventing cell replication.
91
What is Cis-trans Isomerism?
A type of stereoisomerism that can occur within transition metal complexes.
## Footnote
Substituents are either on the same side/ next to each other (cis) or on opposite sides (trans). Cis-trans isomerism occurs in Pt(NH3)2Cl2.
92
What is a Complex Ion?
An ion which has a central metal atom (typically a transition element) surrounded by ligands.
93
What is Coordination Number?
The number of dative covalent bonds formed between ligands and a metal ion centre.
94
What is a Dative Covalent (Coordinate) Bond?
A type of covalent bond in which one bonding atom provides both electrons in the bonding pair.
95
What is d-Block?
The part of the periodic table containing elements in which the highest energy electron is in a d orbital.
96
What is Disproportionation?
A reaction in which the same element is both oxidised and reduced.
97
What is Electron Configuration?
The arrangement of electrons into orbitals and energy levels around the nucleus of an atom/ ion.
98
What is Haemoglobin?
A protein which is important for oxygen transport in blood.
99
What is Ligand Substitution?
A reaction in which one ligand in a transition metal complex is replaced by another.
## Footnote
Typically, these reactions are associated with a colour change.
100
What is a Monodentate Ligand?
A substance that can form 1 dative covalent (coordinate) bond with a metal ion/ metal.
## Footnote
E.g. H2O, Cl- and NH3.
101
What is Octahedral?
The shape of a transition metal complex with a coordination number 6.
## Footnote
E.g. [Cu(H2O)6]2+.
102
What is an Optical Isomer?
Compounds that have the same structural formulae but are mirror images of one another.
## Footnote
Optical isomerism occurs in [Ni(en)3]2+.
103
What is an Oxidation State?
A number that represents the number of electrons lost or gained by an atom of an element. A positive oxidation number indicates the loss of electrons.
104
What is a Precipitation Reaction?
A reaction in which 2 aqueous solutions are combined to form a solid (a precipitate).
105
What is Qualitative Analysis?
Techniques that are used to identify whether or not an element, functional group or ion is present in a sample.
106
What is a Redox Reaction?
A reaction in which oxidation of one species and reduction of another occurs.
107
What does Square Planar refer to?
One of the possible shapes of a transition metal complex with a coordination number of 4.
## Footnote
E.g, Pt(NH3)2Cl2.
108
What is Stereoisomerism?
A type of isomerism in which compounds have the same structural formula but a different arrangement of atoms in space.
109
What does Tetrahedral refer to?
One of the possible shapes of a transition metal complex with a coordination number of 4.
## Footnote
E.g. CuCl4^2-.
110
What are Transition Elements?
d-block elements that can form an ion with an incomplete d-subshell. Transition elements have more than one oxidation state, form coloured ions and can act as catalysts.
111
Atomic (Proton) Number
The number of protons in the nucleus of an atom.
112
Bohr Model
Describes an atom as a small dense nucleus with electrons orbiting around the nucleus.
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Cations
Positively charged ions.
114
d-block
The part of the periodic table in which the elements have their highest energy electron in a d-orbital.
115
Electron Configuration
The arrangement of electrons into orbitals and energy levels around the nucleus of an atom / ion.
116
First Ionisation Energy
The removal of one mole of electrons from one mole of gaseous atoms. Factors affecting it include the strength of attraction between the electron and the nucleus, the nuclear charge, and the atomic radius.
117
Giant Covalent Lattice
A network of atoms bonded by strong covalent bonds (e.g. carbon and silicon). Typically insoluble with high melting and boiling points.
118
Giant Metallic Lattice Structure
The structure of all metals, made up of cations and delocalised electrons. Typically insoluble with high melting and boiling points.
119
Group
A column in the periodic table.
120
Melting Point
The temperature at which a solid melts and becomes a liquid.
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Metallic Bonding
Strong electrostatic attraction between cations and delocalised electrons.
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p-block
The part of the periodic table in which the elements have their highest energy electron in a p-orbital.
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Period
A row in the periodic table.
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Periodicity
A repeating trend in physical and chemical properties across the periods of the periodic table.
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s-block
The part of the periodic table in which the elements have their highest energy electron in an s-orbital.
126
Successive Ionisation Energies
The energy required to remove each electron one-by-one from one mole of gaseous atoms / ions.
127
Base
A substance that can accept H+ ions from another substance. Group 2 compounds can be used as bases.
128
Group 2 Oxide
A compound with the general formula MO, where M is a group 2 element.
129
Oxidation
The loss of electrons / increase in oxidation number.
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Redox
A reaction in which oxidation of one element and reduction of another occurs.
131
Reduction
The gain of electrons / decrease in oxidation number.
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Second Ionisation Energy
The removal of one mole of electrons from one mole of gaseous 1+ ions to form one mole of 2+ ions.
133
Boiling Point
The temperature at which a liquid boils and becomes a gas.
134
Diatomic Molecules
Molecules that are made up of 2 atoms.
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Displacement Reaction
A reaction in which one atom is replaced by another.
136
Disproportionation
The oxidation and reduction of the same element.
137
Induced Dipole-Dipole Interactions
Forces of attraction between molecules caused when the random movement of electrons creates a temporary dipole.
138
London Forces
Another name for induced dipole-dipole interactions.
139
Precipitation Reaction
A reaction in which two aqueous solutions are combined to form an insoluble salt (a precipitate).
140
Anion
A negatively charged ion.
141
Ammonium Ion
An ion with the formula NH4+. The test for ammonium ions is a reaction with warm NaOH, which forms NH3.
142
Cation
A positively charged ion.
143
Carbonate
A salt containing the CO3^2- anion.
144
Halide
A salt containing a group 7 anion.
145
Qualitative Analysis
Identifies the elements present in a substance, typically using test-tube reactions.
146
Sulfate
A salt containing the anion SO4^2-. A reaction between SO4^2- and Ba^2+(aq) will form a precipitate.
147
Activation Energy
The minimum energy required for a reaction to take place.
148
Average Bond Enthalpy
The energy required to break one mole of gaseous bonds.
149
Endothermic
A reaction which takes in energy (ΔH is positive).
150
Enthalpy (H)
A value that represents the heat content of a system.
151
Enthalpy Change (ΔH)
The change in the heat content of a system during a reaction.
152
Enthalpy Change of Combustion (ΔcH)
The enthalpy change that takes place when one mole of a substance is completely combusted.
153
Enthalpy Change of Formation (ΔfH)
The enthalpy change that takes place when one mole of a compound is formed from its elements.
154
Enthalpy Change of Neutralisation (ΔneutH)
The enthalpy change that takes place when one mole of water is formed from a neutralisation reaction.
155
Enthalpy Change of Reaction (ΔrH)
The enthalpy change that is associated with a particular chemical equation.
156
Enthalpy Profile Diagram
Shows the difference in the enthalpy of reactants and products as well as the activation energy of a reaction.
157
Exothermic
A reaction which gives out energy (ΔH is negative).
158
Hess’ Law
The enthalpy change of a reaction is independent of the route it takes.
159
Standard Conditions
A pressure of 100 kPa and a temperature of 298K.
160
Standard State
The physical state (s, l, g, aq) of a substance under standard conditions.
161
Boltzmann Distribution
A graph showing the distribution of the energies of molecules in relation to the activation energy.
162
Catalyst
A substance that speeds up the rate of a reaction without being used up.
163
Collision Theory
The theory which states that molecules must collide with sufficient energy at the correct orientation for a reaction to occur.
164
Concentration
The amount of a substance that is dissolved per unit volume of solution.
165
Heterogeneous Catalyst
A catalyst that is in a different state to the reactants.
166
Homogeneous Catalyst
A catalyst which is in the same state as the reactants.
167
Pressure
The force that a gas exerts on the walls of a container.
168
Rate of Reaction
A measure of how quickly a reactant is used up / a product is formed.
169
Compromise
Balancing several different factors in order to get the best possible outcome.
170
Dynamic Equilibrium
A closed system in which the rates of the forward and reverse reactions are equivalent.
171
Homogeneous Equilibrium
An equilibrium in which all reactants are in the same state.
172
Le Chatelier’s Principle
When a system in dynamic equilibrium is subject to change, the position of equilibrium will shift to minimise the change.
173
KC
The equilibrium constant that is equal to the concentration of products raised to their stoichiometric coefficients divided by the concentration of reactants.
