Working with enthalpy change for dissolution
In a coffee-cup calorimeter, 1.10 g of NH4NO3 is mixed with 76.0 g of water at an initial temperature of 25.00°C. After dissolution of the salt, the final temperature of the calorimeter contents is 23.93°C. Assuming the solution has a heat capacity of 4.18 J/°C · g and assuming no heat loss to the calorimeter, calculate the enthalpy change for the dissolution of NH4NO3 in units of kJ/mol.
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Solution Preview
We have heat evolved in the reaction as,
q = m x c x dT
here, m = 1.10 + 76 = 77.1 g
c = 4.08 J/C g
dT = T final - Tinitial = 23.93 - 25 = - 1.07 C
Therefore, q = -77.1 * 4.08 * 1.07 = -336.59 J
That is after dissolution heat is ...
Solution Summary
The solution gives not only the answers but also the steps required to arrive at the answer. No mathematical step was avoided in the derivation.