1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Equilibrium problem

  1. May 25, 2013 #1

    I've been working on my assignment and the purpose of it is to determine the concentration of a contaminant present in a sample of water. I've discovered the contaminant is ammonium phosphate with the levels of each being 200% higher than normal water. I obtained these results using an ion-selective electrode and a colorimeter.

    Probe Results:
    Ammonium: 407.14 mg/L
    Phosphate: 9.42 mg/L

    I have to determine the amount of ammonium phosphate originally put into the sample of water, and its concentration (molarity). Usually I would do an "ICE" table but I don't know how much ammonium phosphate has originally been put in. I've done the stoichometry and determined that the 3:1 ratio between ammonium and phosphate does not exist (as the probe results suggest). Regardless, I have to determine the amount originally put in (preferably in grams) and the molarity of the solution.

    I have no idea where to start, as I said before I would usually do an ICE table but that will not work in this case.


    Probe readings show a total of approximately 407 mg/L of ammonium and 9.5 mg/L of phosphate. What process would I do in order to determine the original amount put in, and the molarity of the concentration.

    Any help would be much appreciated.
  2. jcsd
  3. Jun 8, 2013 #2
    how did you come to the conclusion that it is ammonium phosphate? Not challenging you, but your answer my help me understand your procedure better and potentially help you.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted