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Tasha
Lv 7
Tasha asked in Science & MathematicsChemistry · 1 decade ago

Calorimetry question?

In order to measure the enthalpy change for this reaction, 1.25g of NH4NO3 is dissolved in enough water to make 25.0mLof solution. The initial temperature is 25.8 C and the final temperature (after the solid dissolves) is 21.9 C

Calculate the change in enthalpy for the reaction inkJ (Use 1.0 g/mL as the density of the solution and 4.18 J/g*C as the specific heat capacity.)

3 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    If 1.0g/ml is the density of the solution then

    25.0ml(1g/ml) = 25g NH4NO3

    Use q = mc∆t

    q = 25g(4.184)(3.9) = 408 joules

  • 5 years ago

    The best answer is correct, for those of you using pearson remember your answer needs to be in kJ/mol. Divide his 408J by 1,000 and then divide by the moles of NH4NO3 (.015625). The answer should come out to about 26.112 or 26kJ/mol with sig figs

  • Anonymous
    6 years ago

    where did u get the 3.9 from?

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