Question

Hemoglobin contains 0.25%iron by weight. If one molecule of hemoglobin contains 4 atoms or iron, find the molecular mass of hemoglobin.

Answer 1

Given,

Hemoglobin contains 0.25%of iron by weight.

It means that

100gm of hemoglobin contains Fe= 0.25gm

Let the mass of hemoglobin (one molecule) be x gm

So...again,

100gm of hemoglobin contains Fe= 0.25gm

....

1 gm of hemoglobin contains Fe= 0.25/100gm.

..

x gm of hemoglobin contains Fe= (0.25/100)*x gm.

..

.now given that,

One molecule of hemoglobin contains 4 atoms of iron.

But.

Molecular weight of one atom of Fe = 56gm.

So weight of 4atoms of Fe will be = 4*56= 224....

Now...

According to question,

(0.25/100)*x = 224.

...... Solving it we get x= 8.9*10⁴........

See picture!!

... Hope it helped you!!

Answer 2

if there is 4 atoms of fe atomic mass of fe is 224 molecular mass is 224×100/.25=224×4=896 is answer