Working with enthalpy change for dissolution

Not what you're looking for? Search our solutions OR ask your own Custom question.

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

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.

© BrainMass Inc. brainmass.com December 24, 2021, 4:55 pm ad1c9bdddf
https://brainmass.com/chemistry/energetics-and-thermodynamics/working-with-enthalpy-change-for-dissolution-16312

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.

$2.49