July 16, Week 7 Today: Temperature and Heat, Chapter 11 Final - PowerPoint PPT Presentation

July 16, Week 7 Today: Temperature and Heat, Chapter 11 Final Homework #7 now available. Due Monday at 5:00PM. Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Temperature - A measure of the average kinetic energy of the molecules “Measure” ⇒ A number directly proportional to the average kinetic energy Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Temperature - A measure of the average kinetic energy of the molecules “Measure” ⇒ A number directly proportional to the average kinetic energy In the U.S. there are currently three temperature scales used: Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Temperature - A measure of the average kinetic energy of the molecules “Measure” ⇒ A number directly proportional to the average kinetic energy In the U.S. there are currently three temperature scales used: Celsius scale Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Temperature - A measure of the average kinetic energy of the molecules “Measure” ⇒ A number directly proportional to the average kinetic energy In the U.S. there are currently three temperature scales used: Celsius scale - Pure water at sea level freezes at 0 ◦ C and boils at 100 ◦ C Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Temperature - A measure of the average kinetic energy of the molecules “Measure” ⇒ A number directly proportional to the average kinetic energy In the U.S. there are currently three temperature scales used: Celsius scale - Pure water at sea level freezes at 0 ◦ C and boils at 100 ◦ C Fahrenheit scale Thermodynamics 16th July 2014

Temperature In all phases, the molecules have random speeds. (In liquids and gases, the molecules have random directions too.) Temperature - A measure of the average kinetic energy of the molecules “Measure” ⇒ A number directly proportional to the average kinetic energy In the U.S. there are currently three temperature scales used: Celsius scale - Pure water at sea level freezes at 0 ◦ C and boils at 100 ◦ C Fahrenheit scale - Pure water at sea level freezes at 32 ◦ F and boils at 212 ◦ F Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. On the Kelvin scale, absolute zero = 0 K (No degree sign.) Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. On the Kelvin scale, absolute zero = 0 K (No degree sign.) The spacing on the Kelvin scale was chosen to be the same as the Celsius scale Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. On the Kelvin scale, absolute zero = 0 K (No degree sign.) The spacing on the Kelvin scale was chosen to be the same as the Celsius scale ⇒ So any equation with ∆ T can use either ∆ T ( K ) = ∆ T ( ◦ C ) Kelvin or Celsius Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. On the Kelvin scale, absolute zero = 0 K (No degree sign.) The spacing on the Kelvin scale was chosen to be the same as the Celsius scale ⇒ So any equation with ∆ T can use either ∆ T ( K ) = ∆ T ( ◦ C ) Kelvin or Celsius From experiment, 0 K = − 273 ◦ C Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. On the Kelvin scale, absolute zero = 0 K (No degree sign.) The spacing on the Kelvin scale was chosen to be the same as the Celsius scale ⇒ So any equation with ∆ T can use either ∆ T ( K ) = ∆ T ( ◦ C ) Kelvin or Celsius From experiment, 0 K = − 273 ◦ C ⇒ T ( K ) = T ( ◦ C ) + 273 Thermodynamics 16th July 2014

Kelvin Scale The Kelvin scale is based on the physical definition of temperature. Lower temperature ⇒ lower kinetic energy ⇒ slower speeds Absolute Zero - The lowest possible temperature. At absolute zero, all molecular motion would stop. On the Kelvin scale, absolute zero = 0 K (No degree sign.) The spacing on the Kelvin scale was chosen to be the same as the Celsius scale ⇒ So any equation with ∆ T can use either ∆ T ( K ) = ∆ T ( ◦ C ) Kelvin or Celsius From experiment, 0 K = − 273 ◦ C ⇒ T ( K ) = T ( ◦ C ) + 273 Also, T ( ◦ C ) = 5 9 ( T ( ◦ F ) − 32 ◦ ) Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K (b) 100 ◦ F , 100 ◦ C , 100 K Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K (b) 100 ◦ F , 100 ◦ C , 100 K (c) 100 K , 100 ◦ C , 100 ◦ F Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K (b) 100 ◦ F , 100 ◦ C , 100 K (c) 100 K , 100 ◦ C , 100 ◦ F (d) 100 K , 100 ◦ F , 100 ◦ C Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K (b) 100 ◦ F , 100 ◦ C , 100 K (c) 100 K , 100 ◦ C , 100 ◦ F (d) 100 K , 100 ◦ F , 100 ◦ C (e) 100 ◦ C , 100 K , 100 ◦ F Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K (b) 100 ◦ F , 100 ◦ C , 100 K (c) 100 K , 100 ◦ C , 100 ◦ F (d) 100 K , 100 ◦ F , 100 ◦ C (e) 100 ◦ C , 100 K , 100 ◦ F Thermodynamics 16th July 2014

Temperature Exercise Which of the following is the correct ranking of temperatures from coldest to hottest? (a) 100 ◦ C , 100 ◦ F , 100 K (b) 100 ◦ F , 100 ◦ C , 100 K 100 K = − 173 ◦ C = − 279 ◦ F (c) 100 K , 100 ◦ C , 100 ◦ F (d) 100 K , 100 ◦ F , 100 ◦ C 100 ◦ C = 212 ◦ F = 373 K (e) 100 ◦ C , 100 K , 100 ◦ F Thermodynamics 16th July 2014

Ideal Gas In the case of an Ideal Gas, the relationship between the average kinetic energy of the molecules and the temperature was discovered by Ludwig Boltzmann. Thermodynamics 16th July 2014

Ideal Gas In the case of an Ideal Gas, the relationship between the average kinetic energy of the molecules and the temperature was discovered by Ludwig Boltzmann. Ideal Gas - A gas with no interaction between the molecules except for their random, elastic collisions. Thermodynamics 16th July 2014

Ideal Gas In the case of an Ideal Gas, the relationship between the average kinetic energy of the molecules and the temperature was discovered by Ludwig Boltzmann. Ideal Gas - A gas with no interaction between the molecules except for their random, elastic collisions. K av = 3 Average kinetic energy for a single 2 k B T molecule in an ideal gas Thermodynamics 16th July 2014