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Homework Help: Enthalpy change of a neutralisation reaction

  1. Mar 3, 2017 #1
    1. The problem statement, all variables and given/known data
    Given the reaction K2CO3(s) + 2HCl(aq) → 2KCl(aq) + CO2(g) + H2O(l), I need to find the enthalpy change in J, given that:
    The specific heat capacity of water is 4.2J g-1 °C-1, and
    The mass change of potassium carbonate is 2.98g, and the temperature change was °6C, and the volume of acid used was 30cm3.

    2. Relevant equations
    ΔH = -qmΔT
    number of moles of acid neutralised = number of moles of water formed

    3. The attempt at a solution
    Considering it is a neutralisation reaction, I did the ΔH = -qmΔT equation. So, -4.2x-2xm=x
    But what do I use for m?
  2. jcsd
  3. Mar 3, 2017 #2


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    Science Advisor

    What undergoes a temperature change of 6°C?
  4. Mar 4, 2017 #3

    We only do neutralisation, combustion and formation enthalpy changes.
  5. Mar 4, 2017 #4


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    Staff: Mentor

    I am afraid you have not understood nor answered the mjc's question, which points you in the right direction.

    You can't blindly apply any formula without knowing what it describes.
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