Definitions for CER Flashcards
0
Q
Define: saturated hydrocarbon
A
A hydrocarbon with single bonds only
1
Q
Define: Hydrocarbon
A
An organic compound that contains only hydrogen and carbons
2
Q
Define: unsaturated hydrocarbon
A
A hydrocarbon containing at least one carbon-carbon double bond
3
Q
Define: Homologous series
A
Is an organic series with the same functional group but with each member differing by CH2
4
Q
Define: functional group
A
Is part of an organic molecule responsible for its chemical properties
5
Q
Define: Alkane
A
The homologous series without double bonds and the general formula
CnH2n+2
6
Q
Define: Alkene
A
They Homologous series with the double bond and the general formula
CnH2n
7
Q
Define: displayed formula
A
Shows the relative position of all atoms in the molecule and the bonds between them
8
Q
Define: structural formula
A
Shows minimal detail of the arrangement of atoms in the molecule
9
Q
Define: Skeletal formula
A
Four minute with hydrogen atoms removed and only the bonds between carbon atoms show, not the atoms themselves
10
Q
Define: structural isomers
A
Isomer with the same molecular formula but different structural formula
11
Q
Define: positional isomerism
A
A type of structural isomerism. When a functional group is on a different numbered carbon
12
Q
Define: chain Isomerism
A
A type of structural isomerism where branches occur in a chain
13
Q
Define: stereoisomers
A
Isomers with the same structural formula but a different arrangement in space around a double bond
14
Q
Define: E/Z isomers
A
A type of stereoisomerism. Double bond stops rotation and different groups on the carbons on the double bond
15
Q
Define: Homolytic fission
A
When a covalent bond breaks giving an electron to two atoms making two radicals
16
Q
Define: heterolytic fission
A
The breaking of a covalent bond with both of the bonded electrons going to one of the atoms forming a cation (-ve) and an anion (+ve)
17
Q
Define: radical
A
Series with an unpaired electron
18
Q
Define: nucleophile
A
(Nucleus loving) an atom (or group of atoms) that is attracted to an electron-deficient centre or atom, where it donates a pair of electrons to form a new covalent bond
19
Q
Define: Electrophile
A
(Electron loving) an electron pair acceptor
20
Q
Define: addition reaction
A
When a species adds to another species. Requires a double bond
21
Q
Define: substitution reaction
A
When a species replaces another species in a reaction
22
Q
Define: elimination reaction
A
When a molecule is removed from another molecule making a double bond
23
Q
Define: nucleophilic substitution
A
A type of substitution reaction in which a nucleophile is attracted to an electron-deficient centre or atom, where it donates a pair of electrons to form a new covalent bond
24
Define: free radical substitution
When a halogen replaces an H in a reaction three steps initiation, propagation, termination
25
Define: electrophilic addition
When a species adds across a double bond
26
Define: fractional distillation
When crude oil is split into its components by their boiling points
27
Define: cracking
When a long chain alkane is split into a short chain alkanes and an Alkene
28
Define: combustion
When a compound is burned completely in oxygen to form Carbon dioxide and water
29
Define: incomplete combustion
When a compound burned in oxygen to form carbon, or carbon monoxide and water
30
Define: pi bond
Formed by the sideways overlap of adjacent P orbitals - always use diagram
31
Define: polymer
Long chain of monomers
32
Define: monomer
Small monomer, usually an alkene, used to build up a polymer
33
Define: oxidation
Loss of electrons or an increase in oxidation number
34
Define: oxidising agent
A reagent that oxidises (takes electrons from) another species e.g. Acidified potassium dichromate
35
Define: reflux
The continual boiling and condensing of the reaction mixture to ensure that the reaction takes place without the contents of the flask boiling dry. Used to make primary alcohols into carboxylic acids or secondary alcohols into ketones
36
Define: distillation
Used to make primary alcohols into aldehydes or secondary alcohols into ketones
37
Define: ester
Formed when an alcohol and carboxylic acid react. -(C=O)-O-(CH2)-
38
Define: percentage yield
Found by (actual amount in moles of product/theoretical amount in moles of product) x100
39
Define: Atom economy
(Mr of the desired product/Mr of all products) X 100
40
Define: IR Spectra
Shows the absorption of IR radiation by bonds to show what bonds are present in a sample
41
Define: mass spectrometry
Shows the mass/charge for fragments of a molecule
42
Define: MS fragment
A piece of the molecule broken in mass spectrometry allows us to piece together the starting molecule
43
Define: Enthalpy (H)
The heat energy stored in a chemical system
44
Define: Exothermic
When the enthalpy is smaller at the end of a reaction than at the beginning. Resulting in heat loss. Bond making. Delta negative
45
Define: endothermic
When the waiter at the end of a reaction then at the beginning. Resulting in him being taken in. Bond breaking. Delta positive
46
Define: activation energy (Ea)
Minimum energy required to start a reaction by the breaking of Bonds
47
Define: Enthalpy profile diagram
Shows the enthalpy of the reactants and products along with the activation energy and Enthalpy change
48
Define: standard conditions
Pressure of 100 KPa and a temperature of 298K. In solution concentration of 1M
49
Define: standard state
The state we find a substance in under standard conditions
50
Define: standard enthalpy change of reaction
Is the enthalpy change that accompanies a reaction of 1 mol of reactants on the standard conditions and in standard states
51
Define: standard enthalpy change of combustion
Is the enthalpy change when one mole of reactant is burned completely in oxygen under standard conditions
52
Define: standard enthalpy change of formation
Is the enthalpy change when one mole of product is formed from its constituent elements in standard states under standard conditions
53
Define: specific heat capacity (C)
Energy required to heat 1g of substance by 1K
54
Define: bond enthalpy
Is the enthalpy change when one mole of a given bonds is broken by home and lytic vision in a gassious state
55
Define: Hess's Law
"If a reaction can take place by more than one late and the little and final conditions are the same, the total involve be changed is the same for each route."
56
Define: rate of reaction
The change in concentration of a reactant or product in a given time
57
Define: catalyst
A species that lowers the activation energy of the reaction by providing an alternative route but is not used itself
58
Define: Boltzmann distribution
Is the distribution of energies of molecules within the sample at a given temperature
59
Define: dynamic equilibrium
An equilibrium in a closed system where the rate for the reaction equals that of the reverse reaction leaving constant concentration of Products and reactants
60
Define: Le Chatelier's principle
When change is imposed on the system in dynamic equilibrium the position of the equilibrium will change to minimise the change
61
Define: the greenhouse effect
The process by which absorption and subsequent emission of infrared radiation by atmospheric gases warms the lower atmosphere and the planets surface
62
Define: Troposphere
Lowest layer of atmosphere surface between 7 km and 20 km
63
Define: stratosphere
Second layer of atmosphere contains ozone layer. From 20 km to 50 km
64
Define: adsorption
Process by which a gas, liquid or solute is held to a solid surface - such as in the catalytic converter
65
Define: acid
The species that is a proton donor
66
Define: addition polymer
Molecular chain forward by repeated addition reactions of many unsaturated alkene molecules (monomers)
67
Define: addition polymerisation
The process in which unsaturated alkene molecules (monomers) add onto a growing polymer chain one of the time to form a very long saturated molecular chain (the addition polymer)
68
Define: alicyclic hydrocarbon
A hydrocarbon with carbon atoms joined together in a ring structure
69
Define: aliphatic hydrocarbons
A hydrocarbon with carbon atoms joined together in a straight or branched chains
70
Define: alkali
A type of bass that dissolves in water forming hydroxide ions, OH- ions
71
Define: alkyl group
And alkane with a hydrogen atom removed, E.g. CH3, C2H5; alkyl groups are often shown as R
72
Define: amount of substance
The quantity whose unit of the mole. Chemists use amount of substance as a means of counting atoms
73
Define: anhydrous
A substance that contains no water molecules
74
Define: anion
And negatively charged ion
75
Define: atomic orbital
A region within an atom that can hold up to 2 electrons, with opposite spins
76
Define: atomic (proton) number
The number of protons in the nucleus of an atom
77
Define: Avogadro's constant
The number of atoms per mole of the carbon 12 isotope of (6.02×10^23 mol^-1)
78
Define: base
A species that is a proton acceptor
79
Define: biodegradable material
A substance that is broken down naturally in the environment by living organisms
80
Define: carbanion
And organic Ion in which a carbon atom has a negative charge
81
Define: cation
A positively charged ion
82
Define: cis-trans isomerism
A special type of E/Z isomerism in which there is a non-hydrogen group and the hydrogen atoms on each C of a C=C double bond: the cis isomer (Z isomer) has the H atoms on each carbon on the same side; the trans-isomer (E) has the H atoms on each carbon on different sides of the bond
83
Define: compound
A substance formed from two or more chemically bonded elements in a fixed ratio, usually shown by chemical formula
84
Define: concentration
The amount of solute, in mol, per 1dm³ (1000 cm³) of solution
85
Define: coordinate bond
A shared pair of electrons which has been provided by one of the bonding atoms only; also called a dative covalent bond
86
Define: covalent bond
A bond formed by a shared pair of electrons
87
Define: Curly arrows
A symbol used in reaction mechanisms to show the movement of electron pair in the breaking or formation of a covalent bond
88
Define: dative covalent
A shared pair of electrons which has been provided by one of the bonding atoms only also called a coordinate bond
89
Define: dehydration
And elimination reaction in which water is removed from a saturated molecule to make an unsaturated molecule
90
Define: delocalised electrons
Electrons are shared between more than two atoms
91
Define: displacement reaction
A reaction in which a more reactive element replaces a less reactive element from an aqueous solution of the latter's ions
92
Define: disproportionation
The oxidation and reduction of the same element in a redox reaction
93
Define: electron configuration
The arrangement of electrons in an atom in
94
Define: electronegativity
A measure of the attraction of a bonded atoms for the pair of electrons in a covalent bond
95
Define: electron shielding
There are potion between electrons in different in the shells. The shielding reduces the net attractive force from the positive nucleus on the outer shell electrons
96
Define: enthalpy cycle
A diagram showing alternative routes between reactants and products which allows the indirect determination of an enthalpy change from other known enthalpy changes using Hess' Law
97
Define: giant covalent lattice
A three-dimensional structure of atoms, bonded together by strong covalent bonds
98
Define: giant ionic lattice
A three-dimensional structure of oppositely charged ions, bonded together by strong ionic bonds
99
Define: giant metallic lattice
A three-dimensional structure of positive ions and delocalised electrons bonded together by strong metallic bonds
100
Define: group
Vertical column in the periodic table. Elements in group have similar chemical properties and the atoms have the same number of outer shell electrons
101
Define: heterogeneous catalysis
A reaction in which the cast list has different physical state from the reactants; frequently, reactants are gases whilst the catalyst is a solid
102
Define: homogeneous catalyst
A reaction in which the catalyst and reactants are in the same physical state which is most frequently the aqueous or gaseous state
103
Define: hydrated
Crystalline and containing water molecules
104
Define: hydrogen bond
A strong dipole-dipole attraction between electron-deficient hydrogen atom (O-H[Delta +ve] or N-H[Delta +ve]) on one molecule and lone pair of electrons on the highly electronegative atom (H-O:[Delta -ve] or H-N:[delta-ve]) on a different molecule
105
Define: hydrolysis
A reaction with water or aqueous hydroxide ions that breaks the chemical compound into two compounds
106
Define: initiation
The first step in a radical substitution in which the free radicals are generated by ultraviolet radiation
107
Define: intermolecular force
An attractive force between neighbouring molecules. Intermolecular forces can be van der Waals' forces (induced dipole-dipole forces), permanent dipole-dipole forces or hydrogen bonds
108
Define: Ion
Are positively or negatively charged atom (covalently bonded) or group of atoms (a molecular ion)
109
Define: ionic bonding
The electrostatic attraction between oppositely charged ions
110
Define: first ionisation energy
The energy required to remove one electron from each eye on it one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions
111
Define: (second) ionisation energy
The energy required to remove one electron from each I am in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions
112
Define: (successive) ionisation
A measure of the energy required to remove each electron in turn
113
Define: energy
E.g. the second ionisation energy is the energy required to remove one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions
114
Define: isotope
Atoms of the same element with different numbers of neutrons and different masses
115
Define: limiting reagent
The substance in a chemical reaction the runs out first
116
Define: lone pair
And outer shell pair of electrons that is not involved in chemical bonding
117
Define: mass (nucleon) number
The number of particles (proton and neutron is) in the nucleus
118
Define: mechanism
A sequence of steps showing the path taken by electrons in a reaction
119
Define: metallic bond
The electrostatic attraction between positive metal ion is delocalised electrons
120
Define: molar mass, M
The mass mole of a substance. The units of molar mass are gmol^-1
121
Define: molar volume
The volume per mole of gas. Units of molar volume are dm³mol^-1. At room temperature and pressure at the mole volume is approximately
24dm³mol^-1
122
Define: Mole
The amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope
123
Define: molecular formula
The number of atoms of each element In a molecule
124
Define: Molecular ion, M+
The positive ion formed in mass spectrometry when a molecule loses an electron
125
Define: molecule
A small group of atoms held together by covalent bonds
126
Define: Oxidation number
A measure of the number of electrons does an atom uses the bond with atoms of another element. Oxidation numbers are derived from a set of rules
127
Define: period
Horizontal row of elements in the periodic table. Element show trends in properties across a period
128
Define: periodicity
A regular periodic variation of properties of elements with atomic number and position in the periodic table
129
Define: permanent dipole
A small charge difference across a bond resulting from a difference in electronegativities of the bonded atoms
130
Define: permanent dipole-dipole force
An attractive force between permanent dipoles in neighbouring polar molecules
131
Define: polar covalent bond
A bond with a permanent dipole
132
Define: polar molecule
A molecule with an overall dipole, taking into account any dipoles across bonds
133
Define: precipitation reaction
The formation of a solid from a solution during a chemical reaction. Precipitates are often formed when two aqueous solutions are mixed together
134
Define: principal quantum number, n
A number representing the relative overall energy of each orbital, which increases with distance from the nucleus. The sets of orbitals with the same n value are referred to as electron shells or energy levels
135
Define: propagation
The two repeated steps in radical substitution that build up the products in the chain reaction
136
Define: redox reaction
A reaction in which both reduction and oxidation take place
137
Define: reducing agent
A reagent that reduces (adds electron to) another species
138
Define: reduction
Gain of electrons or a decrease in oxidation number
139
Define: relative atomic mass, Ar
The weighted mean mass of an atom of an element compare to 1/12 of the mass of an atom of carbon-12
140
Define: relative formula mass
The weighted mean mass of the formula unit compared with 1/12 of the mass of an atom of carbon 12
141
Define: relative isotopic mass
The mass of an atom of an isotope can paired with 1/12th of the mass of an atom of carbon 12
142
Define: relative molecular mass, Mr
The weighted mean mass of a molecule compared with 1/12th of the mass of an atom of carbon 12
143
Define: repeat unit
The specific arrangement of atoms that occurs in the structure over and over again. Repeated units are included in brackets, outside of which is the symbol n
144
Define: salt
A chemical compound formed from an acid, when an H + ion from the acid has been replaced by metal ion or another positive ion, such as the ammonium ion, NH4+
145
Define: shell
A group of atomic orbitals with the same principal quantum number, n. Also known as the main energy level
146
Define: simple molecular lattice
Three-dimensional structure of molecules, bonded together by weak intermolecular forces
147
Define: species
Any type of particle that takes part in a chemical reaction
148
Define: standard solution
A solution of known concentration. Standard solutions are normally used in titrations to determine unknown information about another unknown substance
149
Define: stoichiometry
The more the relationship between the relative quantities of substances taking part in a reaction
150
Define: sub-shell
A group of the same type of atomic orbitals (S, P, D or F) within a shell
151
Define: termination
The step at the end of a radical substitution went to radicals combine to form a molecule
152
Define: thermal decomposition
The breaking up of a chemical substance with heat into at least two chemical substances
153
Define: van Der Waals forces
Very weak attractive forces between induced dipoles in neighbouring molecules
154
Define: volatility
The ease that a liquid turned into a gas. Volatility increases as boiling point decreases
155
Define: water of crystallisation
Water molecules that form an essential part of the crystalline structure of a compound
