Temperature Kelvin Scale Fahrenheit Scale Celsius Scale

Important Temperatures to Remember What is the boiling point of water? What is the freezing point of water? What is absolute zero?

Gas Laws Charles Law Boyles Law (pressure remains constant) (Temperature remains constant)

Charles Law Examples As Temperature Increases Volume Increases gas laws As Temperature Increases Volume Increases Pressure Remains Constant

Boyle’s Law As Pressure Increases Volume Decreases Temperature remains the Same

Boiling point is defined as the temperature at which the vapor pressure of a liquid is equal to the atmospheric pressure In other words, it is the minimum temperature at which a matter which is in the liquid state gets converted to a matter in the gaseous or vapor state.

What is the difference between boiling and evaporation Evaporation is vaporization that occurs at the surface of a liquid below its boiling point.

In water this occurs at 100 degrees Celsius at sea level.                                                                                                             Boiling is vaporization that occurs when the vapor pressure can overcome the atmospheric pressure. In water this occurs at 100 degrees Celsius at sea level.

So……..How does altitude affect the boiling point of water? On a Mountain: Altitude is higher. Atmospheric pressure is lower. Boiling point is lower. Pressure cooker increases the pressure thus raising the boiling point. Food cooks quicker at higher temperature

Phase Changes

What happens to a time temp graph if the amount of liquid (water) boiled is doubled? What changes on a time temp graph if two different substances are represented?

Note volume of ice and water How do you explain the difference in volume ? Note volume of water

50 cc of ice 200 cc of water 200 J of heat The more heat added the quicker the liquid reached the phase change.

Altitude: 0 m 200 Joules 200 cc of water 50 cc of ice Altitude: 10,000 m 200 Joules 200 cc of water 50 cc of ice

Endothermic : Adding Energy Exothermic: Loosing Energy Endothermic : Adding Energy Altitude: 0 m 180 Joules 200 cc of water Altitude: 0 m --180 Joules 200 cc of water