This forum topic is for students to self-organize study groups, etc.
4 posts • Page 1 of 1
The other day in class Dr. Lavelle mentioned that the big idea of indicators is that the best indicators to use are the ones that have an end point that equals the stoichiometric point of a titration. There is a HW problem in chapter 13 that has us find the range for pH of indicators for a given pH. In that case, it is just +/- 1 of the pH. I do not know whether there will be a problem like this on the final, but as long as you understand this main concept you should be able to answer any questions about indicators.
It is probably a good idea to remember that indicators are weak acids that give a strong color change with pH. The popular indicator phenolphthalein in acid appears colorless, however in base appears pink. The H+ release results in a structural change so light is absorbed differently. The color change for this example occurs when pH=pKIn. A good indicator has an end point = stoichiometric point. Hope this helps.
Who is online
Users browsing this forum: No registered users and 6 guests