Hemoglobin, the oxygen carrying protein in red blood cells, has four iron atoms per molecule and contains 0.340 percent iron by mass. Calculate...

...the molar mass of hemoglobin.

Show complete step by step solution to explain the process and answer.

### 3 Answers | Add Yours

The atomic mass of iron, according to the periodic chart, is 55.8g/mole.

Four atoms of iron is 223g/mole

223 = .34 x

x = 223/.34 = 656 g/mole

I forgot to convert 0.34% to a decimal. The equation should be:

223 = .0034 x

so

x = 65,600 g/mole

0.340 percent iron by mass means in 100g of haemoglobin there are 0.340 g of irons. and the molar mass of iron is 55.85 g/mol

and we know that there are 4 iron mole in a molecule of haemoglobin, so

(4 mol Fe/1 mol haemoglobin) * (55.85 g fe/ 1mol Fe)*(100 g of haemoglobin/0.340 g of Fe)

65705.88 g/mol

so the molar mass of haemoglobin is 65705.88 g/mol or 6.6*10^4 g/mol

now haemoglobin is a protein and the molar mass of protein is express in dalton (1 dalton = 1g/mol)

so the molar mass is 6.6*10^4 dalton.

### Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes