1. Specific Heat Capacity

2. Imagine…
A hot day in Arizona…in your back yard is a metal barbeque and a glass of water. Would you want to stick your hand in the water or touch the bbq?
You would want to touch the water because different substances have different abilities to absorb heat!!

3. Specific Heat Capacity
The quantity of heat required to raise the temperature of 1 gram of a substance by one degree Celsius (or Kelvin)
The unit is J/g(oC)

4. Some Specific Heat Capacities
Substance
Specific heat capacity
in J/g(oC)
Water
4.18
Copper
0.385
Iron
0.449

5. q = mC T Equation: q = heat transferred (in joules)
m = mass (in grams)
C = specific heat capacity
T = change in temperature
T = Tfinal - Tinitial

6. Practice Problem
What is the specific heat of silver if the temperature of a 15.4 g sample of silver is increased from 20.0oC to 31.2oC when 40.5 J of heat is added?

7. Givens: q = mC∆T m = 15.4 g Ti = 20.0oC Tf = 31.2oC q = 40.5 J
C = J/g(oC)

8. Practice Problem
What is the final temp of silver if the temperature of a 5.8 g sample of silver starts out at 30.0oC and 40.5 J of heat is added? The specific heat of silver is .235 J/g(oC).

9. Givens: m = 5.8 g q = mC∆T Ti = 30.0oC q = 40.5 J C = 0.235 Tf = ???
Tf = 60.oC

10. Practice Problem
What quantity of heat is required to raise the temperature of 100 mL of water from 45.6C to 52.8C? The specific heat of water is J/g(C) and water has a density of 1.00 grams/mL.

11. Givens: 100 mL = 100 g q = ? V = 100. mL q = mC∆T Ti = 45.6oC
Tf = 52.8oC
C = 4.184
dwater=1.00
g/mL
100 mL = 100 g
q = mC∆T
q=100(4.184)( ) q=
q=3010 J

12. White Board Calculations Whole Class
Given 132.8J of energy is required to heat 11.17g of aluminum from °C to 28.94°C find the specific heat of aluminum.

13. White Board Calculations Whole Class
2. Given that 242.2J of energy is required to heat 81.6g of copper from 27.5°C to 35.2°C, find the specific heat of copper.

14. White Board Calculations Table Group
3. Given the specific heat of lead is J/g∙K and that it takes 93.4J of energy to heat a sample of lead from 22.3°C to 40.4°C find the mass of the lead.

15. White Board Calculations Table Group
4. Given that the specific heat of copper 0.385J/g∙K and that it takes J of energy to heat a sample of copper from 24.3°C to 49.9°C, find the mass of the copper.

16. White Board Calculations Partners
5. Given that the specific heat of copper is 0.385J/g∙K and if 81.2J of heat is applied to 17.8g of copper by how much will the temperature of the copper increase?

17. White Board Calculations Partners
6. Given that the specific heat of silver is 0.235J/g∙K and if 29.1J of heat is applied to11.4 g of silver by how much will the temperature of the silver increase?

18. White Board Calculations Independent
7. Given that the specific heat of chromium is 0.455J/g∙K find the final temperature after 35.9J of energy is removed from 11.7g of chromium at 28.5°C.

19. White Board Calculations Independent
8. Given that the specific heat of iron is 0.450J/g∙K find the final temperature after 103.4J of energy is removed from 98.2g of iron at 87.3°C.

20. Group Task Cards
Each pair needs to take four of the task cards in the container and work together to answer the four practice problems.
After each group completes their four task cards, trade with the other set of table partners.
After each pair has completed all task cards.
Trade and Check the other pairs answers and math calculations.

21. Follow Up Questions