EL 6- Amount Of Substance Flashcards
1
Q
Define relative atomic mass
A
Mass of atom relative to carbon 12
2
Q
Define relative formula mass (molecular mass)
A
Sum of relative atomic masses of elements making up compound
3
Q
How is number of moles calculated?
A
Mass
Mr
4
Q
Define empirical formula
A
Simplest whole number ratio of atoms of each element in a compound
5
Q
Define molecular formula
A
Actual number of atoms of each element in a molecule
6
Q
What is water of crystallisation?
A
- water molecules are fitted within some ionic lattices
- when crystals are heated, water of crystallisation is removed as steam leaving hydrous solid
7
Q
Why is experimental yield always lower than expected yield in an experiment?
A
- loss of products
- side reactions occurring
- impurities in reactants
- changes in temp and pressure
- if reaction is in equilibrium system
8
Q
What is the equation for percentage yield?
A
Experimental yield
Theoretical yield. X100
