moles Flashcards
1
Q
what is 1 mole
A
6.02 x 10^23
2
Q
how to work out moles
A
mass / MR
3
Q
how to work out mass
A
moles x MR
4
Q
how to work out MR
A
mass / moles
5
Q
how to work out relative formula mass of H2O
A
H2O = 2 hydrogen atoms + 1 oxygen atom
atomic mass of hydrogen= 1
atomic mass of oxygen= 16
since there is 2 hydrogen atoms you need to multiply the atomic mass of one atom by 2 so the atomic mass for hydrogen = 2
2+16=18
the relative formula mass of H2O is= 18!!
6
Q
how to calculate the number of moles
A
example: 30g of H2SO4
first find the relative formula mass
2+32+64=98
moles = mass / MR
the mass is 30g and the MR (relative formula mass) is 98
30/98=0.3061224……
=0.31
7
Q
A
