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    When cobalt(II) chloride is dissolved in water there is an equilibrium between two ions:

    [Co(H2O)6]2+ (aq) + 4Cl–(aq) ⇌ [CoCl4]2–(aq) + 6H2O(l)



    ii What is the effect of adding concentrated hydrochloric acid on the value of Kstab?
    Explain your answer. [2]

    The book's answer = no effect [1]
    only temperature changes affect the value of the equilibrium constant (Kstab)

    But I thought that if you're adding conc HCL, your're increasing the formation of [CoCl4)2-(aq), so there's a higher conc. of products than reactants so kstab value is larger?
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    (Original post by ILoveUSA)
    When cobalt(II) chloride is dissolved in water there is an equilibrium between two ions:

    [Co(H2O)6]2+ (aq) + 4Cl–(aq) ⇌ [CoCl4]2–(aq) + 6H2O(l)



    ii What is the effect of adding concentrated hydrochloric acid on the value of Kstab?
    Explain your answer. [2]

    The book's answer = no effect [1]
    only temperature changes affect the value of the equilibrium constant (Kstab)

    But I thought that if you're adding conc HCL, your're increasing the formation of [CoCl4)2-(aq), so there's a higher conc. of products than reactants so kstab value is larger?
    The book is correct ...

    If you add chloride ions you disturb the equilibrium and the system responds by re-establishing the equilibrium condition by making more of the RHS ...
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    (Original post by charco)
    The book is correct ...

    If you add chloride ions you disturb the equilibrium and the system responds by re-establishing the equilibrium condition by making more of the RHS ...
    but the book said no effect, only temp changes Kstab??
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    (Original post by ILoveUSA)
    but the book said no effect, only temp changes Kstab??
    .. and that's exactly what I said. The system responds to the change and RE-ESTABLISHES the value of kc.

    That means that it adjusts the concentrations so that the value of kc is restored...
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    yes this is true, the temperature hasn't changed so Kc stays the same.

    This is le chatelier's principle, if you add more reactant to the LHS, you will get increased amount of product on the RHS, to minimise the change
 
 
 
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