1. Temperature Conversions

2. Temperature Definition: Temperature is the average kinetic energy, KE, of molecules in a sample. Absolute zero is the temperature at which molecules stop all motion. (PE – potential energy is stored energy) (KE – kinetic energy, energy of motion)

3. Temperature Conversions C  F F = 9/5C + 32 F  C C = 5/9(F-32) C  K K = C + 273 K  C C = K - 273

4. Comparing Temperature Scales 212

5. Temperature Conversions C. Do the following problems on another sheet of paper. Use the conversion equations from above. Show all your work: Knowns & Unknowns, Set-Up & Answer (K = C + 273, F = 9/5C + 32) 1. Convert the following centigrade temperatures into fahrenheit. a. 21 'C (A: 70'F)b. -10 'C c. 300 'Cd. -78.5 'C 2. Convert the following centigrade temperatures into kelvin. a. 21 'C (A: 294 K)b. -10 'C c. 300 'Cd. -78.5 'C 3. Convert the following fahrenheit temperatures into celcius. a. 75 'F (A: 24 'C)b. -10 'F c. 100 'Fd. 212 'F 4. Convert the following kelvin temperatures into celcius. a. 77 K (A: -196 'C)b. 198.5 K c. 373 Kd. 500 K

6. Part C Temperature Conversions Answer Key ABCD 170F14F572F-109F 2294K263K573K195K 324C-23C38C100.C 4-196C-75C100.C227C

7. Temperature Quiz (include problem, work & answer) 1.456 K = ? C C = K – 273 C = 456 – 273 C = 183C 2.456 C = ? F F = 9/5C + 32 F = 9/5(456) + 32 F = 853F (round to nearest 1 due to adding 32)

8. Heat & Calorimetry Heat (Q) – is defined as the kinetic energy associated with the motion of countless atoms and molecules which can be transferred between objects of different temperature. Temperature (T) – the average kinetic energy of the atoms or molecules in a sample of matter. Calorimetry – measurement of the amount of heat gained or lost in a chemical reaction.

9. Calorimetry Calculations Equation: q = C p x m x  T q = heat C p = specific heat (heat capacity), the amount of heat needed to raise up the temperature of 1 g of the specific substance 1 degree C. m = mass of sample tested  T = change of temperature of sample Solve the equation for Cp: Cp = q / (m  T )

10. Specific Heat Lab http://sciencegeek.net/VirtualLabs/SpecificHe atLab.html http://sciencegeek.net/VirtualLabs/SpecificHe atLab.html Do 3 trials for each substance: wood, copper, glass, silver, sodium & water Make 2 tables for each substance: Observations & Data Table, Calculations Table Calculate Cp for all 6 substances with 3 trials each for a total of 18 calculations.

11. Observations & Data Material____________Trial #1Trial #2Trial #3 Mass of object, m (g)ggg Initial temperature of object (T 1 ) ºC Final temperature of object (T 2 ) ºC Energy absorbed (Joules)JJJ

12. Calculations: Material____________Trial #1Trial #2Trial #3 ΔT = (T 2 - T 1 )ºC C p = q / (m  T) J/(g · ºC)