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Unformatted text preview: °C) (20°C) = 420 J If you continue to add heat energy once the temperature of the ice reaches 0°C , the heat absorbed is called
the heat of fusion (Lf). This heat is used to cause a change of phase (from a solid to a liquid). This heat is
increasing the potential energy of the molecules of the solid. No temperature change takes place. Each
substance has its own heat of fusion. The heat of fusion for ice is 340 Joules/g. Exactly the same amount
of heat is given up when 1.0 g of water is changed to ice. This heat is called the heat of crystallization.
The general equation for calculating heat energy to change a solid to a liquid is:
Heat = Mass x Heat of Fusion
Q = m Lf
Calculate the heat necessary to change 10 g of ice(s) at 0°C to 10 g of water(l) at 0°C.(B-C) Q = mLf = (10 g)( 340 J/g) = 3400 J CHEMISTRY HEATING CURVE WORKSHEET B. LIQUID PHASE
Liquids have a definite volume, but assume the shape of their container. If a drop of colored dye is placed
into a beaker of liquid, the dye will slowly spread throughout the liquid (without being stirred) until it is
equally dispersed. The movement of the dye ind...
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- Winter '14