Page 164 - Chemistry eBook

Heating Curve Chart (Part 3)
Horizontal line (phase change):
1. There is NO temperature change and NO kinetic energy change.
This happens because the the heat is being used to change the phase. The temperature line is not moving up
in temperature. (It’s sleeping.) Time is moving
along, but the temperature stays the same.
2. Potential energy is high because:
a. No energy is being used now.
b. The substance has to store the energy that it
got from taking in so much heat along the way.
Plateau (straight
horizontal line) means phase change, and potential energy change
Line DE is longer than line BC. Why? It takes more time and energy to change a liquid to a gas than to change a solid to a liquid.
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