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Chemistry, calculation problem

  • 03-05-2012 12:37pm
    #1
    Stalin and rugby
    Closed Accounts Posts: 243 ✭✭


    Quote from our chem book I don't understand how they got the answer, any help is appreciated peeps!

    "Dissolve 0.01g calcium hypochlorite in deionised water and make the solution up to one litre. This gives a stock solution of 5ppm free chlorine"

    How does it give 5ppm? It's on page 286 if you want to look it up. Cheers tweeps
    Tagged:


Comments

  • #2
    partyatmygaff
    Registered Users, Registered Users 2 Posts: 10,992 ✭✭✭✭partyatmygaff


    Calcium hypochlorite =/= Free chlorine

    10mg calcium hypochlorite [LATEX]Ca(ClO)_2[/LATEX] is comprised of:

    Molecular weight: 143g
    Calcium = 40/143 = 27.9%
    2CL = 71/143 = 49.65%
    2O = 32/143 = 22.37%

    Your only concern is the chlorine which forms 49.65% of the crystal. 10mg of calcium hypochlorite in 1L solution is 10ppm.

    10mg of calcium hypochlorite contains (Approximately) 4.965mg of free chlorine.


  • #3
    Stalin and rugby
    Closed Accounts Posts: 243 ✭✭Stalin and rugby


    fair play, thanks


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