Advertisement
Help Keep Boards Alive. Support us by going ad free today. See here: https://subscriptions.boards.ie/.
If we do not hit our goal we will be forced to close the site.

Current status: https://keepboardsalive.com/

Annual subs are best for most impact. If you are still undecided on going Ad Free - you can also donate using the Paypal Donate option. All contribution helps. Thank you.
https://www.boards.ie/group/1878-subscribers-forum

Private Group for paid up members of Boards.ie. Join the club.

Chemistry, calculation problem

  • 03-05-2012 01:37PM
    #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


Advertisement