Question

13. Myoglobin stores oxygen for metabolic process in
muscle. Chemical analysis shows that it contains
0.32% Fe by mass. If there is one Fe atom per
molecule of myoglobin, what is the molar mass of
myoglobin? [Fe = 56]
(1) 1.75 x 104 g/mol (2) 3.5 x 105 g/mol
(3) 1 x 104 g/mol (4) 2.5 x 105 g/mol​

Answer 1

$\huge{\mathfrak{Answer:-}}$

$\bf{1.74\times10^{4}\;gmol^{-1}}$

$\huge{\mathfrak{Explanation:-}}$

1 molecule of Myoglobin has 1 atom of iron. So, mass percentage for 1 molecule is:

$\bf{=\frac{Mass\;of\;Fe}{Mass\;of\;molecule} \times 100}$

$\bf{0.32=\frac{56}{Molar\;mass\;of\;Myoglobin}\times 100}$

${\boxed{\boxed{\bf{Molar\;mass\;of\;Myoglobin=1.74\times 10^{4}\;gmol^{-1}}}}$