Chapter 17, Problem 103AE

(a)

Interpretation Introduction

Interpretation: The enthalpy of solution for the dissolution of ${\text{NH}}_{\text{4}}\text{NO}$ in the units of kJ/mol needs to be determined, if the heat capacity of solution is 4.18 J/°C.g and 1.60 g of ${\text{NH}}_{\text{4}}\text{NO}$ is mixed with 75.0 g of water at an initial temperature of 25.00°C and final temperature was 23.34°C

Concept Introduction: A coffee cup calorimeter is the device that is used to measure the amount of heat involved in a chemical or physical process. During any exothermic chemical process the heat is released so temperature increases whereas during an endothermic chemical process temperature decreases as the heat is absorbed.

This temperature change can be used along with the specific heat and mass of the solution to calculate the amount of heat involved or released during the process. The heat change and specific heat can be related with the given formula:

  $\text{q = m }\times \text{C }\times \Delta \text{T}$

Here;

• m = mass of substance
• C = specific heat
• $\Delta \text{T}$= Temperature change

(b)

Interpretation Introduction

Interpretation: The lattice energy of ${\text{NH}}_{\text{4}}\text{NO}$ needs to be determined if the enthalpy of hydration is -630 kJ/mol and enthalpy of solution is 26 kJ/mol.

Concept Introduction: A coffee cup calorimeter is the device that is used to measure the amount of heat involved in a chemical or physical process. During any exothermic chemical process the heat is released so temperature increases whereas during an endothermic chemical process temperature decreases as the heat is absorbed.

This temperature change can be used along with the specific heat and mass of the solution to calculate the amount of heat involved or released during the process. The heat change and specific heat can be related with the given formula:

  $\text{q = m }\times \text{C }\times \Delta \text{T}$

Here;

• m = mass of substance
• C = specific heat
• $\Delta \text{T}$= Temperature change