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!

How would I find the volume of the solution?

  1. Nov 26, 2016 #1
    Hey guys had a midterm yesterday but I got stumped on a question with really no idea how to solve it, I'm not really looking for an answer more of a what steps to solve this sort of question. I don't remember exactly what the question was but it was along the lines of Na2CO3 nH2O (This isn't the exact formula just an example since I don't recall what it was) has a molarity concentration of 0.1M find the volume of the solution when the hydrate has a molar mass of x (x was given but I don't remember what it was).
    1. The problem statement, all variables and given/known data
    Find the volume of 0.1M of Na2CO3 nH20 with a molar mass of x (x was given in midterm just not sure what it was)
    Cm=0.1M
    M (Na2CO3 nH20) = x
    V= ?

    2. Relevant equations
    n=m/M
    CM= n/v

    3. The attempt at a solution
    I figured with the molar mass of the entire hydrate given I would subtract that from the molar mass of the anhydrate then divide that by the molar mass of water, 18, in order to find out the coefficient for H2O. But from here I got stuck as I seemed to be missing another variable in order to calculate either the mass or number of mols in the hydrate.
     
  2. jcsd
  3. Nov 26, 2016 #2

    Borek

    User Avatar

    Staff: Mentor

    Doesn't make sense as worded.

    Exactly.
     
  4. Nov 26, 2016 #3
    Wording may be a bit off since I don't remember what it was exactly, but since these were the only variables given would it be safe to assume it was just a test error?
     
  5. Nov 27, 2016 #4

    Borek

    User Avatar

    Staff: Mentor

    Assuming you have not missed something - yes, that would be my take.
     
  6. Nov 28, 2016 #5

    Dr Uma Sharma

    User Avatar
    Gold Member

    I think x is the mass of the hydrate and you need to calculate first the number of moles to work out the volume.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted