1. U3 S2 L2 Calculating Enthalpy Textbook Readings MHR
pages : Calculating Enthalpy Changes
pages : Enthalpy Changes and Changes of State
pages : Enthalpy of Solution
page 648: Heat Absorbed or Released a Physical Change
Textbook Practice Items MHR
page 645: items 19, 20, 21a-c, 22 and 23
pages : items 24, 25, 26, 27a-c, 28 and 29
pages : items 3, 5 and 8a-b
Homework postings: page 658: items 13, 14a-b, 15, 16a-c, 17a-c and 18a-c

2. Upon completion of this lesson, you should be able to:
calculate the heat gained or lost from a system using the formula where ΔH is the molar enthalpy of a phase change or a chemical reaction
calculate the ΔH for a system given the mass of a species (or vice versa)
perform calculations which apply the first law of thermodynamics in determining the heat of a reaction (or phase change) given experimental data for the changes to the surroundings

3. Calculating enthalpy q = n∆H q = heat (enthalpy) (kJ)
n = number of moles of substance (mol)
∆H = molar enthalpy (kJ/mol)
Molar enthalpies for a number of species undergoing chemical or physical changes are known.
Reference data may be found in your MHR textbook. (p 848)
(see Table 16.2 p.642, Table 16.3 p.643, and Table 16.4 p.647).

4. ∆Hfusion = -∆Hsolidification ∆Hvapapourization = -∆Hcondensation

5. Calculate the heat required to melt 50.0 g of ice at 0.0°C.

6. Calculate the heat change that should occur when 10
Calculate the heat change that should occur when 10.4 g of calcium chloride is formed from its elements at SATP conditions.

7. Calculate the heat change that should occur when 5
Calculate the heat change that should occur when 5.0 L of propane is burned at SATP conditions.

8. Calculate the heat change that should occur when 4
Calculate the heat change that should occur when 4.00 g of ammonium nitrate dissociates in water. ΔHsoln = 25.7 kJ/mol.

9. A 2.00 g sample of methanol was burned at SATP conditions resulting in heat gain of 45.3 kJ in the surroundings. Calculate the molar enthalpy of combustion for methanol.

10. A 945. 6 g chunk of ice at 0. 0°C absorbs 68. 6 kJ of heat
A g chunk of ice at 0.0°C absorbs 68.6 kJ of heat. Calculate the mass of ice that remains.

11. Calorimetry
The addition of 5.32 g of lithium perchlorate to mL of calorimeter water resulted in a temperature change from 20.44°C to 23.45°C in the calorimeter. Calculate the molar enthalpy of solution formation for lithium perchlorate.