Chemistry help???????

Question

I have a chemistry problem that I can't quite solve. Here it is:

The doctor told Miriam she was tired and pale because she was low in iron. The iron tablets Miriam was given to take did not look like the iron nails they used in woodwork.

Discuss how the CHEMICAL differences between the iron in the tablets and the iron in the nails are related to their uses.

Thanks in advance!!

Answer 1

To watch the label of that kind of tablets you'll find it out.Simple Fe could hardly be digested by our stomach,so it should be Fe2+.

Answer 2

Actually the iron in the tablets and the iron in the nail are chemically the same thing, metallic iron.  The iron in the tablets is iron powder and the tiny amount of iron is mixed with a binder.

I'm betting that Miriam could have ground up her tablet to a powder and then passed a magnet through the powder and picked up the iron.  You can do the same with much of the "iron fortified" breakfast cereals.

If you look on the ingredients of the tablets, it will say "reduced iron", which is another way of saying "metallic iron".

Now, why would you take iron powder?  Iron (II) and iron (III) are both found in hemoglobin.  But in order to carry oxygen, the body needs iron in the +2 oxidation state in hemoglobin.  If you were to consume FeCl2 (for instance) in which iron was in the +2 oxidation state, then the acid in your stomach (HCl) would oxidize much of it to the +3 oxidation state, which won't help the anemia much.

But if you consume metallic iron, then when it is oxidized by the stomach acid it goes to Fe2+ and is now useful for making hemoglobin and for carrying oxygen around the body.

===== Follow up ======

JNDionys..., you would be amazed at what your stomach could digest.  The hydrochloric acid in your stomach is a little over 1M and can easily react with iron metal or zinc or magnesium.  You could swallow a strip of magnesium and burp hydrogen gas, although this is not recommended because of the heat that is also generated.  

The iron metal in cereal and iron tablets is well documented.  There are lots of activities designed to show this to students.

http://www.mcrel.org/whelmers/whelm07.as...

And no, the iron cannot be ingested as Fe2+ because, as I've already pointed out, it would be oxidized to Fe3+ which does NOT transport oxygen.  The anemia is what Miriam had in the first place and therefore needs Fe2+.

That said, there are some preparations of iron (II) (iron (II) sulfate, or ferrous sulfate) that are given for anemia.  Usually these are enteric, meaning that they are coated pills, rather than chewable tablets.  The pills are coated so that they don't dissolve in the stomach, but in the small intestine, instead.  There is no HCl in the small intestine to oxidize the Fe2+ and so it is absorbed as the iron ion that can be incorporated into hemoglobin.

Answer 3

I assume it's an ionic compound of iron that will dissociate in your stomach.