Titration question of unknown compound?

Question

If a 2.893g sample of an unknown compound containing iron requires 28.45mL of permanganate solution to reach the endpoint, calculate the % Fe in the unknown

im really stuck on this one

and instructions/tips/answers would be very much appreciated

molarity of KMnO4 is .02M

Answer 1

You need the molarity of the permanganate solution to figure this out. Oncve you have that, you can figure out the number of moles of permanganate you used, then you can use the ratio of permanganate to iron in the reaction (5 irons for 1 permanganate) to determine the moles of iron, convert that to mass of iron, then ratio with the total mass to get %Fe.

Answer 2

Hey man,

Ok work out the number of moles of permanganate solution using:

Volume x Molarity/ 1000 = No of moles.

This will let you figure out how many moles of Iron the Permanganate solution has reacted with. If the reaction is in the ratio 1:1 then the number of moles of iron will be the same as the number of moles of Permanganate. You must check the ratio of moles to get the next part correct.

Next you use:

Moles x RAM = Mass

NOTE: RAM will be that of iron on its own.

To work out the mass of Iron in the unknown compound.

Then just divide the mass you worked out by 2.893 and times tha answer by 100 and you'll have your percentage.

Hope that helps!

Answer 3

0.075L x 0.a million HCl = 0.0075moles HCl used NaOH neutralizes HCl in a a million:a million ratio. 0.0141L NaOH x 0.1M = 0.00141moles NaOH used to neutralize extra HCl 0.0075moles HCl used - 0.00141moles extra = 0.00609moles HCl to neutralize the carbonate for each a million CO3 2-, there are 2 H+ required to neutralize it. for this reason, moles metallic carbonate = a million/2 moles HCl = 0.003045moles 0.28g metallic carbonate / 0.003045moles = ninety one.95g/mole

Answer 4

not enough info...
I need either the reaction equation and/or the permanganate concentration