I'm not quite sure what this question was asking or why I got it wrong.
Hoping you guys could tell me exactly how I read the question.
Ammonium Nitrate dissolves according to the following reaction:
NH4NO3 → NH4+NO3-
In order to measure the enthalpy change for this reaction, 1.25g of NH4NO3 is dissolved in enough water to make 25.00mL of solution. The initial temperature is 25.8 C and the final temp is 21.9 C.
Calculate the change in enthalpy for the reaction in kJ. (Use 1.0 g/mL as the density of the solution and 4.18 J/gC as the specific heat capacity.)
This was my process:
q
sol = (25g)(4.18J/gC)(-3.9) = -407.55 J
q
rxn=407.55
ΔH
rxn = 407.55 / 0.0156 moles NH
4NO
3 =
26kJNow, I got this wrong. The correct answer is supposed to be .41kJ.
I see where that number is (first step in finding finding q
sol), but
was I wrong in understanding exactly what the question was asking?
What did I end up finding? I mean, if it was only asking for q
rxn,
then why did it bother giving grams of NH
4NO
3?