1. Chapter 9-3 Specific Heat Capacity
St. Augustine Preparatory School
January 12, 2017

2. Note:
We will be doing a lab on calorimetry Monday and Tuesday. The lab report that will be completed will take place of the test for chapter 9.
You will work in groups for the lab but the report will be done individually in a Google Doc.

3. Specific Heat Capacity: the amount of energy required to change the temperature of 1.0 kg of a substance by 1.0 degree Celsius.
Formula:
cp is specific heat capacity, with units: J/kg°C
Q is the heat energy, with units: J
m is the mass of the sample, with units: kg
ΔT is the temperature, with units: °C

4. The heat water absorbs (Qw) is equal to the heat the object loses (Qx)
In a closed system, the energy released by one object is equal to the energy absorbed by the other.
Calorimetry: used to find heat changes in reactions, as well as specific heat capacities for different objects.
We use water in calorimeters since we know the specific heat of water.
Qw = -Qx
The heat water absorbs (Qw) is equal to the heat the object loses (Qx)

5. Practice Problem: Suppose a piece of iron with a mass of 21
Practice Problem: Suppose a piece of iron with a mass of 21.5 g at a temp of °C is dropped into an insulated container of water. The mass of the water is g and its temperature before adding the iron is 20.0 °C. What will be the final temp of the system? Specific heat capacity of iron is 4.48x102 J/kg°C. Specific heat capacity of water is 4.186x103 J/kg°C.

6. A 12. 48 g sample of an unknown metal, heated to 99
A g sample of an unknown metal, heated to 99.0 °C was then plunged into 50.0 mL of 25.0 °C water. The temperature of the water rose to 28.1 °C. Assuming no loss of energy to the surroundings: a. How many joules of energy did the water absorb? b. How many joules of energy did the metal lose? c. What is the specific heat capacity of metal?

7. What is the final temperature when a 3
What is the final temperature when a 3.0kg gold bar at 99 degrees Celsius is dropped into 0.22kg of water at 25 degrees Celsius. SHC of gold is 1.29x102 J/kg°C and the SHC of water is 4.186x103 J/kg°C.