Homework Help

You are given three test tubes labeled A B C without knowing what concentration of...

user profile pic

rexadventurebear | Student, Grade 9 | (Level 1) Honors

Posted November 26, 2012 at 9:55 PM via web

dislike 1 like

You are given three test tubes labeled A B C without knowing what concentration of glucose is in each one.  Which experiment would you use to find the solution which solution is the most concentrated?

1 Answer | Add Yours

user profile pic

ncchemist | eNotes Employee

Posted November 27, 2012 at 3:44 AM (Answer #1)

dislike 1 like

We are given three test tubes each with a different concentration of glucose in it.  The best chemical test to determine which one is the most concentrated would be to add a solution of KMnO4 (potassium permanganate) in acidic solution (such as HCl) to a small sample from each tube.  KMnO4 is a purple solution that turns colorless as it reacts to oxidize glucose in solution.  So take a small sample (say about 1 mL) from each of the tubes and measure the amount of a solution of acidic KMnO4 that is needed to be added to each sample to keep the purple color from disappearing.  The most concentrated sample will require the most KMnO4 to be added to oxidize all of the glucose present.

Sources:

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes