This question was closed for being unresearched homework.
I am not sure why this is the case. According to the Biology FAQ:
What should I do before I ask the question?
Research it yourself - even if you try and can't find the answer or understand the concept you need you can then include what you have found out yourself in the question. Search the site to see if something similar has been asked before.
How should I ask my question?
Include details of how you have attempted to form a solution. We will not do your homework assignments for you but we will point you in the right direction if you have made the effort to research the topic first.
It seems that the poster did do his/her research, and arrived at a strange result - the concentration decreasing (probably due to a miscommunication), but the poster did in fact do their research, and arrived at the correct result too. While I think this question could probably be closed on other grounds (too specific an event), it doesn't appear to be poorly researched.
I would therefore like to understand the rationale of others on closing this question for "insufficient research".