physical definitions A1 Flashcards
1
Q
Define isotopic mass
A
- mass of an atom
- of an isotope
- compared to 1/12th of an atom
- of carbon 12
1
Q
Define relative atomic mass
A
- weighted mean mass
- of an atom of an element
- compared to 1/12th of an atom
- of carbon 12
2
Q
Define molecular mass
A
- mean mass of a molecule
- compared to 1/12th of an atom
- of carbon 12
3
Q
Define the mole
A
- amount of substance
- containing as many particles
- as there are carbon atoms
- in 12g of carbon 12
4
Q
Define Avogadro’s constant
A
- the number of atoms
- per mole
- of the carbon 12 isotope
5
Q
Define molar mass
A
- mass per mole of a substance
6
Q
Define empirical formula
A
- smallest whole number ratio
- of atoms of each element
- in a compound
7
Q
Define molecular formula
A
- actual number of atoms
- of each element
- in a compound
8
Q
Define standard enthalpy change of reaction
A
- enthalpy change when a reaction occurs
- under the molar quantities
- shown in the chemical equation
9
Q
Define standard enthalpy change of formation
A
- enthalpy change when 1 mole of a compound
- is formed from its elements
- under standard conditions
10
Q
Define standard enthalpy change of combustion
A
- enthalpy change when 1 mole of a substance
- reacts with oxygen
- under standard conditions
11
Q
Define standard enthalpy change of neutralisation
A
- enthalpy change when an acid and an alkali react
- to form 1 mole of water
12
Q
Define average bond enthalpy
A
- breaking of 1 mole of bonds
- in gaseous molecules
