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    hellloooooo, need some help please

    i know its a pretty bog standard question, but i just cant get head or tail of it. its to do with acids and bases

    Q1. calculate the pH of the diluted solution
    you have 25cm3 of 0.1 moldm-3 HCl
    you add to this 100cm3 of water

    i calculated the pH at the start..
    and its a flatline after that :confused:

    please and thank you
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    pH = -log [H+]

    HCl is a strong acid, so fully dissociates.
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    (Original post by gingerbreadman85)
    pH = -log [H+]
    i did that for the start already
    i just dont know what its asking afterwards because theyve given volumes
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    what is the new concentration? that'll let you work out the new pH
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    (Original post by gingerbreadman85)
    what is the new concentration? that'll let you work out the new pH
    doesnt say..
    or could i work out the mols of HCl..
    then get the new conc. of the solution (conc=mols/vol)
    then put that into pH = -log[H+]

    the mols bit seems a bit out there though :confused:
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    Exactly, so find the moles of HCl initially, then find the new concentration with 125cm3 as the new volume. Now you have [HCl] which = [H+] so you can use pH = -log[H+]
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    (Original post by l4ith)
    Exactly, so find the moles of HCl initially, then find the new concentration with 125cm3 as the new volume. Now you have [HCl] which = [H+] so you can use pH = -log[H+]
    thanks
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    it gives you enough info to work out the new concentration, it's just a simple dilution.
 
 
 
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