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Boiling and Freezing. Chapter 14. Boiling. The process in which a liquid changes phase to a gas. Boiling Point. The temperature at which, under “Standard” conditions, a liquid will change into a gas. Boiling Point.
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Boiling and Freezing Chapter 14
Boiling • The process in which a liquid changes phase to a gas.
Boiling Point • The temperature at which, under “Standard” conditions, a liquid will change into a gas.
Boiling Point • At the boiling point, the vapor pressure of the liquid will equal the outside atmospheric pressure. • No longer will the atmosphere “Hold” the liquid down (or in) and the liquid “Jumps” out of the container as a gas.
Boiling Point • The vapor pressure is determined by the number of solute particles, and the colligative properties of the solution.
Boiling Point • To increase the boiling point, add more solute. • ΔTb = Kb * m
Boiling Point • ΔTb = Kb * m • ΔTb = elevation of BP • Kb = molal constant • m = molality
Boiling Point • Chart page 500 • Chart page 501
Freezing point depression • ΔTf= Kf* m
Freezing point depression • You can figure it out…
Freezing point depression • Chart page 502
Video • Ice-Ice Baby • https://www.youtube.com/watch?v=25SHX5Sj7ZA • Slip sliding away • https://www.youtube.com/watch?v=Wp2sqrfGSPI • ??? • https://www.youtube.com/watch?v=ST1fUaKIBMs
Problems • 1. You have a 20 m Na Cl in a water solution. What is the boiling point and the freezing point of this solution? • 2. Find the freezing and boiling point of a 5 m Na Cl and Ethanol solution?
Problems • 1 a. (20 m * .512 C/m) +100 C = • 1 b. (20 m * -1.86 C/m) + 100 C = • 2 a. (5m * 1.22 C/m) + 78.5 C = • 2 b. (5m * -1.99 C/m) + -114.1 C =
Problems • Page 503: 45 (aqueous means “In water”), 46 • Page 510: 116
Energy • The ability to do work.
Energy • Law of Conservation of energy states that energy cannot be created nor destroyed.
Energy • calories – • Energy it takes to raise the temperature of 1.0 g of water • Calories = 1000 calories
Energy • Specific Heat – The amount of heat it takes to raise 1.00 gram of the material, 1.00 degree C. • Table 2 page 520
Energy • q = c *m * ΔT • q = heat absorbed • c = specific heat • m = mass • ΔT= Change in temperature
Problems • Page 521: 4, 5, 6
Videos • Temp • https://www.youtube.com/watch?v=wK_G-1hs-l0 • Measuring calories • https://www.youtube.com/watch?v=LG8Y21cwL6M • Fitness • https://www.youtube.com/watch?v=6WWmM1jpM8I • Oooops… • https://www.youtube.com/watch?v=vh7GmDIKM5c