moles

Question 1

what is 1 mole

Answer 1

6.02 x 10^23

Question 2

how to work out moles

Answer 2

mass / MR

Question 3

how to work out mass

Answer 3

moles x MR

Question 4

how to work out MR

Answer 4

mass / moles

Question 5

how to work out relative formula mass of H2O

Answer 5

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!!

Question 6

how to calculate the number of moles

Answer 6

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