1. Exothermic or Endothermic?
Exothermic releases energy into the surrounding as heat. As a result, the temperature of the surrounding increases.
Endothermic absorbs energy from the surrounding. As a result, the temperature of the surrounding decreases.

2. Endothermic or Exothermic?

3. 5.2 Calorimetry and Enthalpy

4. Task
Read pages
In your notebook, write the definitions of the keywords

5. Specific Heat Capacity
Substance A has a specific heat capacity of 4.18 and substance B has specific heat capacity of What does this mean?
This means that A needs more thermal energy than B to raise the temperature of A by 1 degrees.

6. Calorimetry Calculations
q = mcΔT q= total amount of thermal energy absorbed or released m=mass of the substance c=specific heat capacity ΔT = change in temperature (final-initial)

7. Sample Problem 1
Let’s do sample problem 1 from page 295 together!

8. You have to finish it in class!
Task
Do questions 1-8 from the handout.
You have to finish it in class!

9. Enthalpy Change
Enthalpy (H) the total amount of thermal energy in a substance
Enthalpy Change (ΔH) the energy released to or absorbed from the surroundings during a chemical or physical change
Molar Enthalpy Change (Δ 𝐻 𝑟 ) the enthalpy change associated with a physical, chemical, or nuclear change involving 1 mol of a substance.

10. Calculating ΔH
It is hard to find the enthalpy (H) of a given substance but we can calculate enthalpy change (ΔH) of a reaction
What is ΔH?
ΔH = 𝐻 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 − 𝐻 𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠
If ΔH > 0, endothermic reaction (positive)
If ΔH < 0, exothermic reaction (negative)
Also, as long as pressure stays constant, ΔH = |q|
We know how to calculate q (q = mcΔT)
So, if we know q for a reaction, we know the value of ΔH

12. Molar Enthalpy Change
(Δ 𝐻 𝑟 ) is the general formula for molar enthalpy change for any reaction type.
There are different types of molar enthalpy changes
(Table 2 on page 299):

13. Connecting Enthalpy Change and Molar Enthalpy Change
The amount of enthalpy change depends on the quantity of matter that undergoes the change
For example, it takes more energy to convert 1 L of liquid water to water vapor than it does for 500 mL
So, to calculate the enthalpy change for some amount of substance other than 1 mol, you need to use the following formula:
ΔH = nΔ 𝐻 𝑟

14. Task
Copy down Sample Problem 1 and 2 from the board

17. HOMEWORK Required Reading: p. 292-306
Make notes on Representing Molar Enthalpy Changes and copy down the sample problems
Do practice problems 1-4 from page 301
Do questions 1-7 on page 306