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supahman
Nov10-11, 08:43 PM
1. The problem statement, all variables and given/known data

Hi there, I am asked this question in one of my lab calculation questions:

Calculate the number of moles of I2 produced from 25 mL of the diluted KIO3 solution.

Information that has already been obtained from my lab:

-Molar concentration of dilute KIO3: 0.00241 + or - .5% M
-Molar concentration of stock KIO3 solution : 0.0241 + or -0.05%

-Mass of I2: 253.8 g/mol
-Mass of KIO3:



2. Relevant equations

-Avogadro's Constant: 6.02214 X 10^23

3. The attempt at a solution

-Was not able to properly attempt the questions, as I am unsure where to being and how to complete it.

symbolipoint
Nov10-11, 10:15 PM
Your question should be, find how much I2 is produced from the given quantity of KIO3. This is assuming that the KIO3 is the source of the produced I2.

Your part of the reaction would include: KIO3 → (1/2) I2

You have enough information for how much moles of KIO3, and you know that half a mole of I2 comes from one mole of KIO3.

By any chance, does the situation have additional important information which you did not include?

Borek
Nov11-11, 03:36 AM
This is assuming that the KIO3 is the source of the produced I2.

Which is probably not a correct assumption.

(I guess that's what you hinted at in your last statement.)

supahman
Nov11-11, 11:13 AM
Hey there,

That was all the information I was given. The I2 is what is used to produce the stock KIO3, which is then diluted with filtered water.

Borek
Nov11-11, 11:22 AM
What you wrote is opposite of the standard iodometric procedure.

http://www.titrations.info/iodometric-titration

supahman
Nov11-11, 04:56 PM
Huh? I'm actually asked that question... So I really don't know what to make of it. :s

Borek
Nov11-11, 05:17 PM
Perhaps you are expected to know what the standard procedure is. Potassium iodate is a primary substance, and the way it is used is well known.