1. Heat and Temperature

2. The difference Heat – the energy that flows from hot to cold. Measured in Joules (J) or calories (cal). Temperature – measure of average kinetic energy. Measured in Celsius (C) or Kelvins (K).

3. What factors affect the amount of heat flow? Mass (m) – grams, kilograms Change in temperature (  T) – Kelvins Specific heat (C) – amount of heat required to raise the temperature of 1 g of a substance 1 degree. Different substances have different C values! Values in reference tables.

4. Calculations Q = Cm  T Heat Specific heat Mass Change In Temp.

5. Practice Problems 1. How much heat is lost when a solid aluminum ingot with a mass of 4110 g cools from 660 o C to 25 o C? (Cp for Al = 0.9025 J/g o C) 2. If 7.5 x 10 4 J of energy are released when 500 g of a metal cools from 100.0 o C to 20.0 o C, what is the specific heat of the metal?

6. How is this measured in lab? Calorimetry –Calorimeter –Measures the heat change in a chemical reaction –Closed system –Heat lost = heat gained calculations Image from http://wps.prenhall.com/wps/media/objects/602/616516/Media_Assets/Chapter08/Text_Images/FG08_09.JPG