The flow of energy. Heat and work. Objectives. When you complete this presentation, you will be able to define energy, heat, and work describe the flow of energy in exothermic and endothermic processes use the proper units when calculating energy, heat, and work
The flow of energy
Heat and work
First, we break bonds.
Then, we make bonds.
you divide the amount of heat input, q,
the mass, m, times the temperature change, ∆T.
The temperature of a 95.4 g piece of copper increases from 25.0°C to 48.0°C when the copper absorbs 849 J of heat. What is the specific heat of copper?
m = 95.4 g
∆T = Tf – Ti = 48.0°C – 25.0°C = 23.0°C
q = 849 J
= 0.387 J/g∙°C
Sample Problems: Find the specific heat of each of the following metals that are heated from an initial temperature of 25.0°C to the indicated final temperature using the indicated amount of heat.
C = 0.449 J/g∙°C
C = 1.74 J/g∙°C
C = 0.646 J/g∙°C