Question

How many mL of a 100 mg/dL Ferrozine solution are needed to complex 0.0000002 moles of iron?

1 dL Ferrozine solution contains 100 mg Ferrozine.

DOUBLE CHECK UNITS.

Answer 1

solution:

equation is

[Fe(H2O)6]+2 + 3(FerroZine)-2 -----> fe(FerroZine 3)-4 + 6H2O

equation shows 3 moles of FerroZine complexing with 1 mole of Fe

so moles of FerroZine = 0.0000002 x 3 = 0.0000006 moles

The molar mass of FerroZine is 492.47 g/mole

so mass of FerroZine in 0.0000006 moles = 0.0000006 x 492.47 = 0.000295482 gram or 0.295482 mg

in question 1 dL solution contain 100 mg Ferrozine

So, 1 mg ferrozine conntains in (1/100)dL

therefore,

0.295482 mg will contain in

= (1/100) * 0.295482 =  0.00295482 dL volution of needed

now, we know that

1 dL = 100 ml

therefore,

0.00295482 dL = 0.00295482 * 100 ml = 0.295482 ml

hence ml of a 100 mg/dL Ferrozine solution needed = 0.295482 ml