Chemical Forums

Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Mathijsm on June 30, 2016, 03:20:21 PM

Title: Different results in Iodometry
Post by: Mathijsm on June 30, 2016, 03:20:21 PM
Hey guys,

First of all I'd like to thank you for your help and would like to let you know that I'm a dutch student that has never been taught chemistry in English. If I say something chemistry related that sounds really weird in English feel free to let me know since I simply translate the way of saying it in dutch into English.

We had to measure the amount of Thiosulfate that is used during Iodometry. https://en.wikipedia.org/wiki/Iodometry. We basically followed the entire process that is explained in the section 'Basic principles and then measured the amount of Thiosulate that we used.

The question that I'm asking is what are things that can influence these results? We had many variations ranging from 0.03 ml to 0.17 ml. The things that I've already concluded myself is that I could've simply made a mistake in the measurements (I could've accidently not have pipetted exactly 10 ml of Iodine), but what are the other things that might influence the results? Do things like temperature play a big role in this or are there other things of the environment that could've influenced it?

I hope I've been clear in what my question was. If you still have a question yourself about what exactly it is that I'm asking please feel free to ask me.
Thank you!
Title: Re: Different results in Iodometry
Post by: mjc123 on July 01, 2016, 06:11:00 AM
Quote
We had many variations ranging from 0.03 ml to 0.17 ml.
0.03 ml to 0.17 ml of what? Is that your titre? It looks very small - how did you measure it? If it is, you are using a too concentrated solution of titrant - dilute it so that your titration volume is something larger and accurately measurable, say ca. 20 ml.
Can you detail your measurements and calculations, as in this thread: http://www.chemicalforums.com/index.php?topic=84455.msg306340#msg306340 ? That would help us to help you.