In: Chemistry
The average human body contains 5.70 L of blood with a Fe2+ concentration of 3.20×10−5 M . If a person ingests 7.00 mL of 24.0 mM NaCN, what percentage of iron(II) in the blood would be sequestered by the cyanide ion?
Number of moles of NaCN , n = Molarity x volume in L
= 24.0 mM x 7.00mL
= 24.0x10-3 x 7.00x10-3 L
= 1.68x10-4 mol
The balanced reaction between Fe2+ & NaCN is
Fe(OH)2 + 2 NaCN
Fe(CN)2 + 2 NaOH
From the above reaction
2 moles of NaCN reacts with 1 mole of Fe2+
1.68x10-4 mol of NaCN reacts with (1.68x10-4 )/2 = 8.4x10-5 mole of Fe2+
So Concentration of Fe2+ that would be reacted with Cyanide ion is
= number of moles of Fe2+ reacted / total volume
= 8.4x10-5 mol / 5.70 L
= 1.47x10-5 M
Therefore the percentage of Iron(II) in the blood that sequestered is = [(1.47x10-5 )/(3.20x10-5)]x100
= 46.05 %