Haemoglobin contains 0.25% iron by weight. The molecular weight of haemoglobin is 896000. Calculate the number of iron atom per molecule of haemoglobin.

Explanation

`:' 100 g` haemoglobin has iron `= 0.25 g`
`:. 89600 g` haemoglobin has iron `=(0.25xx89600)/(100)`
`=224 g Fe`
`1` mole or `N` molecule of haemoglobin has `224 g Fe`
`=(224//56)g`-atom of `Fe`
`=4g`-atom of `Fe=4N` atom of `Fe`
`:. 1` molecule of haemoglobin `=4` atom of `Fe`