Lab # 8 Iodine with Thiosulfate

Lab # 8 Iodine with Thiosulfate - adding KI too soon might...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Matthew Li CHE 1110L Lab # 10 The Reaction of Iodine with Thiosulfate November 12, 2011 Locker # 358 Post Lab Questions
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1. What is the purpose of adding starch to this solution? We added starch to the solution because when titrating, the color fades so gradually that the endpoint is almost impossible to detect; starch allows the solution to show a sharp endpoint as iodine molecules become adsorbed on the surface of starch molecules to give an intensel blue complex. 2. In the titration procedure part 1 the instructions tell you to rinse off the stirring rod used to break up crystals. How would your results be affected if you did not do this? In part 2
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: adding KI too soon might result in the loss of I2 by evaporation. How would this affect your answers? Not rinsing off the stirring rod will allow for an easier contamination of the sample, resulting in different numbers for the amount of titrant required to reach the endpoint. Adding KI too soon would cause the I2 to evaporate, causing the number of milliters used to titrate the sample to be relatively low. 3. For all measurements provide an estimate of the uncertainty involved. Estimate the overall uncertainty of your results....
View Full Document

This note was uploaded on 03/25/2012 for the course CHE 1111L-0 taught by Professor Taliaara during the Fall '11 term at St. Johns Duplicate.

Page1 / 2

Lab # 8 Iodine with Thiosulfate - adding KI too soon might...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online