1. Not finding help here? Sign up for a free 30min 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!

Determine the amount of NaOH and Sr(OH)2 based on pOH

Tags:
  1. Jun 26, 2016 #1
    1. The problem statement, all variables and given/known data
    Hello!
    I am trying to solve the following problem:
    A 4.00-L base solution contains 0.100 mol total of

    NaOH and Sr(OH)2 . The pOH of the solution is 1.51.

    Determine the amounts (in moles) of NaOH and

    Sr(OH)2 in the solution.

    2. Relevant equations
    3. The attempt at a solution

    I am stuck because I am not sure I correctly constructing the solution path:

    We have pOH = 1.51, which means that there are 10^(-1.51) moles of OH in solution, i.e. 0.0309 moles per one liter of solution. If I have 4 liters, then shouldn't there be 0.1236 moles of OH in this solution?
    But according to the problem there are only 0.100 moles of NaOH and Sr(OH)2; both are strong bases, therefore there 0.100 moles of OH in the 4 liters of solution. How can that be?
    Where is my mistake?
    Thank you very much!
     
  2. jcsd
  3. Jun 26, 2016 #2

    Borek

    User Avatar

    Staff: Mentor

    How many moles of OH- are produced per 1 mole of dissociating Sr(OH)2?
     
  4. Jun 27, 2016 #3
    2 moles. There are 3 moles of OH- produced by dissociating both NaOH and Sr(OH)2, and two of those come from dissociating Sr(OH)2
     
  5. Jun 27, 2016 #4

    Borek

    User Avatar

    Staff: Mentor

    What does it mean

     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Determine the amount of NaOH and Sr(OH)2 based on pOH
Loading...