NAPLEX Practice calculation, need help with this one, missing one part.

[PharmaTope]

so i was just taking a practice test from appleton and lange. PLEASE NOTE, THIS IS NOT AN ACTUAL NAPLEX QUESTION.

can someoen tell me where this "65" came from in the answer? this part 1 mEq of iron will be 65 divided by valence
am i missing something?

Approximately, how many milliequivalents of ferrous sulfate are present in each dose of the Feosol tablets? [mol wt ferrous sulfate = 152; iron = 56]

(A) 1
(B) 2
(C) 4
(D) 6
(E) 9
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Feosol tablets contain exsiccated (dried) ferrous sulfate. The exsiccated form of ferrous sulfate contains approximately 30% elemental iron, considerably higher than that contained in hydrous ferrous sulfate or ferrous gluconate. Feosol tablets contain 200 mg of dried ferrous sulfate in which iron is present in the reduced form with a valence of +2.

Using the equation: mg = (mEq) (Formula wt) 200 mg = (x mEq) (152)
Valence 2 2
x = 2.6 mEq
The problem may also be solved by first determining the weight of elemental iron present in each tablet.
mg iron = 56 × 200 = 73.7 mg
152
Since 1 mEq of iron will be 65 divided by valence of 2 = 32.5, the mEq of iron present will be 73.7 mg/32.5 = 23 mEq (1; 10; 23)

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[WVUPharm2007]

I think it's a typo of the dyslexic variety. The bloody atomic weight of Fe is 56....not 65. Because it has a charge of -2 when dissociated, it will only take 0.5 mmol to make an mEq. Ergo, 1 mEq is 28mg (56/2). This makes since because the equivalent is a measurement how many bonding spots a molecule has. So the higher the valence of a molecule, the less is needed to make a mEq.

I'll get to their quote at the end...
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Anyway....

The easy way to remember how figure out this mess is to be basic as hell about it. mEq substance=(mmol of substance)(its valence); or, to be dumbed down even more, mEq =

(weight in mg of ion in question/atomic mass of said ion) X
The number appearing after the ion (i.e. K+, Na+=1, Fe+2 = 2, etc)

So in Feosol, 30% of ferrous sulfate by weight is just ferrous (per their calcuations, anyway), therefore; (0.30)(200mg caps) = 60mg of Fe+2 per capsule.

So...we then find how many mmol of iron that is and multiply it by how many binding spots the joint has (which is two).

(mg per cap/atomic weight)= mmol of substance;so, (60/56) = 1.07 mmol Fe-2.
Then,
mmols substance(valence)= mEq of substance; so, 1.07(2) = 2.14 mEq
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So, in this quote

So when it is written

Since 1 mEq of iron will be 65 divided by valence of 2 = 32.5, the mEq of iron present will be 73.7 mg/32.5 = 23 mEq (1; 10; 23)

The used the wrong atomic weight and somehow made 73.7/32.5= 23. Um...yeah. What it should read is:

Since 1 mEq of iron will be 56 divided by valence of 2 = 28, the mEq of iron present will be 60 mg/28 = 2.14 mEq

In a Naplex situation, you would be right in dividing 56/152 to find the ratio of Fe+2 to SO4-2....but, again, in this situation, they tell you it's apparently 30% iron...so that step isn't needed in the example. You just use 0.3 as a multiplier.

If you did it that way; 73.7/28 = 2.63mEq

I think it was just a cluster**** of a question. I'd just ignore it and move on....