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Chemistry OCR > Definitions > Flashcards

Flashcards in Definitions Deck (36)
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1
Q

Isotope

A

atom of same element with different numbers of neutrons and different masses

2
Q

relative isotopic mass

A

mass compared with 1/12th the mass of C-12

3
Q

relative atomic mass

A

weighted mean mass compared with 1/12th mass of C-12

4
Q

ionic bond

A

electrostatic attraction between positive and negative ions

5
Q

giant ionic lattice

A

from oppositely charged ions strongly attracted in all directions

6
Q

average bond enthalpy

A

measurement of strength of covalent bond, breaking of 1 mol of bonds in gaseous atoms

7
Q

electronegativity

A

ability of an atom to attract bonding electrons in a covalent bond

8
Q

periodicity

A

showing repeated trends in physical and chemical properties

9
Q

first ionic energy

A

removal of 1 mol of electrons from 1 mol of gaseous atom

10
Q

exothermic

A

releases energy: combustion

11
Q

endothermic

A

takes in energy: thermal decomposition

12
Q

enthalpy change of formation

A

formation of 1 mol of a compound from its elements

13
Q

enthalpy change of combustion

A

complete combustion of 1 mol of substance

14
Q

enthalpy change of neutralisation

A

formation of 1 mol of water from neutralisation

15
Q

lattice enthalpy

A

1 mol of ionic lattice from gaseous ions and use as a measure of the strength of ionic bonding in a giant ionic lattice

16
Q

enthalpy change of solution

A

dissolving of 1 mol of solute

17
Q

enthalpy change of hydration

A

dissolving of 1 mol of gaseous ions in water

18
Q

general formula

A

simple algebraic formula

19
Q

structural formula

A

minimal detail that shows arrangement of atoms in a molecule

20
Q

displayed formula

A

positioning of atoms and bonds between them

21
Q

skeletal formula

A

organic formula shown by removing hydrogen atoms from alkyl chains: skeleton

22
Q

homologous series

A

organic compounds that have the same functional group but each successive member is differing by CH2

23
Q

structural isomer

A

compound with same molecular formula but different structural formula

24
Q

homolytic fission

A

covalent bond breaks and one electron from bonded pair, goes to each atom forming two radicals

25
Q

hetrolytic fission

A

bonding atom recieveing both electrons from one bonding pair

26
Q

radical

A

species with an unpaired electron

27
Q

curly arrow

A

movement of electron pair, showing hetrolytic fission or formation of covalent bond

28
Q

sigma bond

A

overlap of orbitals directly between bonding atoms

29
Q

pi bond

A

sideways overlap of adjacent p-orbitals above and below the bonding C atoms

30
Q

sterioisomers

A

compounds with same structural formula with different arrangement in space

31
Q

E/Z isomerism

A

restricted rotation about a double bond

32
Q

electrophile

A

electron pair acceptor

33
Q

nucelophile

A

electron pair donor

34
Q

optical isomer

A

non-superimposable mirror image

35
Q

Standard half cell

A

The emf of a half cell compared with a hydrogen half cell at standard conditions

36
Q

Entropy

A

The disorder of a reaction (sum of products -sum of reactants