Question

how many moles of Fe2O3 are there in 320kg of iron 3 oxide ( 1kg =1000g)

Answer 1

Atomic mass of $Fe_2O_3$ is 159.7 u

320 kg = 320000 gm

$159.7 gm = 6.022*10^{23} atoms$
∴ [tex]1 gm = \frac{6.022*10^{23}}{159.7} [/tex]
∴$320000 gm = \frac{6.022*10^{23}}{159.7}*320000 = 120.66 * 10^{25} atoms$