relative formula mass questions Flashcards
1
Q
whats the rfm of Mg(No3)2
A
24+14+14+(16x6) = 143
2
Q
what do we do to work out the relative formula mass
A
we just add the masses of each element together
3
Q
whats the RFM of iron oxide Fe2o3
calculate the mass of the iron
calculate the percentage of iron
A
160
112
70pc
4
Q
how do you calculate percentage mass
A
mass of element/total mass of compound x 100
5
Q
what does RFM mean
A
Mr,,, relative formula mass
6
Q
whats the Mr of Mg(No3)2
A
151
7
Q
how do you workout the reacting masses of reactants and products
A
write the mass given
find what you need to workout the mass of
calculate the RFM
use ratio
calculate the mass of the substance
