Posted by janice on Tuesday, February 22, 2011 at 5:01pm.
All of the texts I have seen say that the iodine color is dark enough that starch is not needed to see the end point; however, I also note that ALL of the texts give instructions that INCLUDE the use of starch for the end point. Personally, I KNOW my eyesight is not good enough to see the end point without starch. Having said that, if the end point IS actually visible, then it should be acceptable not to use starch (provided that one is consistent; e.g., if no aid is used to see the end point for standards, then no aid should be used for the samples).
All of the texts I have seen say that the iodine color is dark enough that starch is not needed to see the end point; however, I also note that ALL of the texts give instructions that INCLUDE the use of starch for the end point. Personally, I KNOW my eyesight is not good enough to see the end point without starch. Having said that, if the end point IS actually visible, then it should be acceptable not to use starch (provided that one is consistent; e.g., if no aid is used to see the end point for standards, then no aid should be used for the samples).
Related Questions
Chemistry-iodometric titration - In an iodometric titration, excess potassium ...
Science : Chemistry - The concentration of dissolved chlorine in tap water can ...
Chemistry - please help - Please help to determine the (%w/w) benzoyl peroxide (...
Chemistry - Are the following chemicals light sensitive? 1) Potassium Iodide (KI...
Chemistry Help Please :) - I'm stuck on how to do these 4 problems ...
Chemistry - What is the purpose of adding zinc chloride in the preparation of ...
chemistry - What is the purpose of adding zinc chloride in the preparation of ...
Chemistry-please help - What is the purpose of adding zinc chloride in the ...
chemistry - When varsol and iodine in potassium iodide aqueous solution is mixed...
chem - When varsol and iodine in potassium iodide aqueous solution is mixed, two...
For Further Reading