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Phase Change Worksheet

Phase Change Diagram The graph was drawn from data collected as a substance was heated at a constant rate. Use the graph to answer the following questions.

At point A, the beginning of observations, the substance exists in a solid state. Material in this phase has _______________ volume and _____________ shape. With each passing minute, _____________ is added to the substance. This causes the molecules of the substance to ____________ more rapidly which we detect by a ________________ rise in the substance. At point B, the temperature of the substance is ______°C. The solid begins to __________. At point C, the substance is completely ____________ or in a ___________ state. Material in this phase has _______________ volume and _____________ shape. The energy put to the substance between minutes 5 and 9 was used to convert the substance from a ___________ to a ___________. This heat energy is called the latent heat of fusion.

Between 9 and 13 minutes, the added energy increases the ______________ of the substance. During the time from point D to point E, the liquid is ___________. By point E, the substance is completely in the __________ phase. Material in this phase has _____________ volume and ___________ shape. The energy put to the substance between minutes 13 and 18 converted the substance from a ___________ to a ___________ state. This heat energy is called the latent heat of vaporization. Beyond point E, the substance is still in the ______________ phase, but the molecules are moving _______________ as indicated by the increasing temperature.

Substance Melting point Boiling point
Bolognium 20 °C 100 °C
Unobtainium 40 °C 140 °C
Foosium 70 °C 140 °C
Which of these three substances was likely used in this phase change experiment?

BONUS: For water, the value for the latent heat of vaporization is 6.8 times greater than the latent heat of fusion. Imagine we were adding heat at a constant rate to a block of ice in a beaker on a hot plate, and it took 4 minutes for the ice to melt completely. How long would it take, after the water started boiling, for the beaker to be completely empty (the liquid water totally converted to water vapor)?