Flashcards in Key words/formulas and their points Deck (64)
Loading flashcards...
1
Acid
A species that is a proton donor
2
Activation energy
The minimum energy required to start a reaction by breaking bonds
3
Addition reaction
A reaction in which a reactant is added to an unsaturated molecule to make a saturated molecule
4
Alkali
A type of base that dissolves in water forming hydroxide ions
5
Alkanes
CnH2n+2
6
Anion
Negative ion
7
Atom economy
atom economy = molecular mass of the desired product / sum of molecular masses of all products x100
8
Orbital
A region within an atom that can hold up to two electrons with opposite spins
9
Average bond enthalpy
The average enthalpy change that takes place when breaking by homolytic fission 1 mol of a given type of bond in the molecules of a gaseous specie
10
Atomic number
Protons in nucleus
11
Avogadros constant
Number of atoms per mole of a carbon - 12 isotope (6.02x1023)
12
Base
Proton acceptor
13
Catalyst
A substance that increases rate of a chemical reaction without being used up
14
Cation
Positively charged ion
15
Cis isomerism
H atoms on same side
16
Trans isomerism
H atoms in different sides
17
Covalent bond
Shared pair of electrons
18
Curley arrow
Show the movement of a pair of electrons
19
Diative covalent bond
Shared pair of electrons provided by one bonding atom only
20
Displacement reaction
Where a more reactive element replaces a less reactive element from an aqueous solution of latter's ions
21
Dynamic equilibrium
-closed system
-forward reaction rate is equal to reverse reaction rate
22
Electronegativity
A measure of attraction of a bonded atom for a pair of electrons in a covalent bond
23
Sheilding
Repulsion of electrons from different inner shells
24
Electrophile
An atom that us attracted to an electron rich centre or atom where it accepts a pair of electrons to form a new covalent bond
25
Elimination reaction
Removal of a molecule from a saturated molecule to make an unsaturated molecule
26
Empirical formula
Simplest whole-number ratio of atoms of each element present in a compound
27
Endothermic
Enthalpy of products is greater than enthalpy of reactants resulting in heat being taken in from surroundings
28
Standard enthalpy change of combustion
The enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states.
29
Standard enthalpy change formation
The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.
30
Standard enthalpy change of reaction
The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states.
31
Esterfication
Alcohol + carboxylic acid > ester + water
32
Exothermic
Enthalpy of the products is smaller than the enthalpy of the reactants resulting in heat loss to surroundings
33
Greenhouse effect
The process in which the absorption and subsequent emission of IR by atmospheric gasses warms the lower atmos and planets surface
34
Group
-Vertical column
-similar chemical properties
-same number of outer electrons
35
Hess's Law
If a reaction can take place by more than one route and the initial and final conditions are the same, the total enthalpy change is the same for each route.
36
Heterolyric fission
The breaking of a covalent bond with both of the bonded electrons going to one of the atoms, forming a cation (+ ion) and an anion (– ion).
37
Homolytic fission
The breaking of a covalent bond with one of the bonded electrons going to each atom, forming two radicals.
38
Homologous series
A series of organic compounds with the same functional group, but with each successive member differing by CH2.
39
Ionic bond
An electrostatic attraction between oppositely charged ions
40
First ionisation energy
The energy required to remove one electron from each atom in one mole of gaseous atoms to form a gaseous 1+ ion
41
le Chatelier's Principle
When a system in dynamic equilibrium is subjected to a change, the position of equilibrium will shift to minimise the change.
42
Mass number
Protons and neutrons in the nucleus
43
Metallic bonding
Electrostatic attraction between positive metal ions and delocalised electrons
44
Mole
Amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon 12 isotope
45
Nucleophile
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.
46
Nuclophilic substitution
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.
47
Percentage yield
% yield = actual amount, in mol, of product/ theoretical amount, in mol, of product x100
48
Period
-horizontal row of elements
-trends in properties
49
Periodicity
Regular periodic variation of elements with atomic number and position in the periodic table
50
Pi-bond
Overlap of p orbitals
51
Propagation
Build up of products in a chain reaction
52
Radical
Species of an unpaired electron
53
Relative atomic mass
The weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12.
54
Relative formula mass
The weighted mean mass of a formula unit compared with one- twelfth of the mass of an atom of carbon-12.
55
Relative isotopic mass
The mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.
56
Relative molecular mass
The weighted mean mass of a molecule compared with one- twelfth of the mass of an atom of carbon-12
57
Saturated hydrocarbon
Single c-c bonds
58
Specific heat capacity
q=mc🔺t
C=4.18
59
Standard conditions
Pressure of 100kPa
Temperature of 298K
Concentration of 1 mol dm-3
60
Stereoisomers
Same structural formula but different arrangement of atoms in space
61
Structural isomers
Same molecular formula but different structural arrangement of atoms
62
Substitution reaction
An atom or group of atoms is replaced
63
Termination
Two radicals combine to form a molecule
64