1. Chapter 10: Energy

2. What is happening when an ice cube melts in your hand? How do fireworks work? What is energy? (answer on space provided on handout)

3. Heat Energy flow caused by a temperature difference Measured in J or cal 1 cal = 4.184 J Temperature Measure of random motion of a substance Measured in ̊ C, ̊ F, or K

4. System vs. Surroundings A burning match Energy is flowing _________ the system therefore the reaction is _____thermic. Melting ice cube Energy is flowing _________ the system therefore the reaction is _____thermic.

5. Calculations Convert temperature Change in temperature Convert to grams of a substance Q=SM∆T

6. Converting T ( ̊ F to ̊ C) Fahrenheit to Celsius T ( ̊ C) = ( T(°F) – 32) x (5/9) Ex: Convert 65 ̊ F to ̊ C T ( ̊ C) = ( T(°F) – 32) x (5/9) T ( ̊ C) = ( 65 °F – 32) x (5/9) T ( ̊ C) = 18. ̊ C

7. Convert T (K to ̊ C) Kelvin to Celsius T ( ̊ C) = T(K) – 273 Ex: Convert 300. K to C T ( ̊ C) = 300. K – 273 T ( ̊ C) = 27. ̊ C

8. Change in T (∆T) ∆T = T final – T initial Ex: If a cup of boiling water is left on the counter until it comes to room temperature (20 ̊ C), what is the change in temperature? ∆T = T final – T initial ∆T = 20 ̊ C – 100 ̊ C ∆T = -80 ̊ C

9. Convert to grams (from mol) Convert 6.00 mol of H 2 O to grams. 6.00 mol H 2 O18.02 g H 2 O = 1 mol H 2 O 108. g H 2 0

10. Q = SM∆T Q = Energy (heat) required in Joules S = specific heat capacity in J/g ̊ C M = mass of the sample in grams ∆T = change in temperature in ̊ C

11. SubstanceSpecific Heat Capacity (J/g ̊ C) air1.00 carbon (graphite)0.711 carbon dioxide0.832 granite0.803 iron0.448 lead0.128 mercury0.14 water (liquid)4.184 ice2.03 steam1.99 Specific Heat Capacity The amount of energy required to raise the temperature of one gram of a substance by one degree Celsius.

12. Q = SM∆T How much energy is needed to warm 7.40 g of water from 17.0 ̊ C to 35.0 ̊ C? Q = want S = 4.184 J/g ̊ C (from table) M = 74.0 g ∆T = 35.0 ̊ C – 17.0 ̊ C= 18.0 ̊ C Q = SM∆T Q = (4.184 J/gC)(7.40 g)(18.0 C) Q = 557 J

13. Q = SM∆T If 72.4 j of heat is applied to a 9.52 g black of metal, the temperature increases by 52.3 F. Calculate the specific heat capacity. Q = S = M = ∆T = Q = SM∆T

14. Calculate the amount of energy required (in calories) to heat 145 g of water from 22.3 ̊ C to 75.0 ̊ C. Q = S = M = ∆T = Q = SM∆T

15. Lab Title, Data, Analysis, and Conclusion need to be in lab notebook

16. Reading 10.2 (pg 291 – 292) 10.5 (pg 294 – 300) Practice Problems Pg 318 - 320 # 6-10, 22-28, 49-58