Volumetric Analysis Lab Calculation Question

[supahman]

Homework Statement

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:

Homework Equations

-Avogadro's Constant: 6.02214 X 10^23

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]

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]

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]

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]

What you wrote is opposite of the standard iodometric procedure.

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

 

[supahman]

Huh? I'm actually asked that question... So I really don't know what to make of it. :s

 

[Borek]

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.