1. Calorimetry Conservation of thermal energy: Final Temperature: m1 m2TL
Final Temperature:

2. Calorimetry Example
An unknown material of mass .062 kg and temperature 87°C is dropped into .35 kg of water at 20°C. When thermal equilibrium is reached, both have a temperature of 25°C. Calculate the specific heat capacity of the unknown substance.

3. Calorimetry
Problem:
A 0.40 kg iron horseshoe that is initially at 500 oC is dropped into a bucket containing 20 kg of water at 22 oC. What is the final equilibrium temperature?
Neglect any heat transfer to or from the surroundings.

4. Calorimetry
Problem:
A 200 g block of copper at a temperature of 90 oC is dropped into 400 g of water at 27 oC. The water is contained in a 300 g glass container. What is the final temperature of the mixture

5. Latent Heat
Energy is required for a material to change phase, even though its temperature is not changing.
(m) Mass of
the object
(L) Latent heat
of the fusion or
vaporization
(Q) Thermal
energy added

6. Heat of fusion, Lf: heat required to change 1
Heat of fusion, Lf: heat required to change 1.0 kg of material from solid to liquid
Heat of vaporization, Lv: heat required to change 1.0 kg of material from liquid to vapor
Heat 14 (13 of 32)

7. Latent Heat Q2= mLf Q4= mLv 3.33 x 105 J 22.6 x 105 J 1 kg Ice -50 oC50
100
150
Q1= mcIDt
1.05 x 105 J
Q3= mcWDt
4.19 x 105 J
Q5= mcSDt
1.01 x 105 J
Specific Heat
Specific Heat
Specific Heat

8. Heat required to convert 1 kg of ice
at -50 oC to steam at 150 oC
Q1 = 1.05 x 105 J
Q2 = 3.33 x 105 J
Q3 = 4.19 x 105 J
Q4 = 22.6 x 105 J
Q5 = 1.01 x 105 J
3.22 x 106 J

9. Problem:
A large block of ice at 0 oC has a hole chipped in it, and 400 g of aluminum pellets at a temperature of 30 oC are poured into the hole. How much of the ice melts?

10. Problem: 100 W A heating coil is placed in a thermally insulated tank
of negligible heat capacity. The tank contains 0.10 kg
of water and kg of ice, both initially at 0 °C. The
coil delivers energy at a rate of 100 W.

11. Find the heat transferred to the
water and ice by the heating coil
in the first 10 s.

12. Find the time required to melt
all of the ice

13. After the ice is melted find the
additional time required to bring
the water to a boil.