University:
California Institute of Technology
Course:
EE/APh 40 | Physics of Electrical Engineering
Academic year:

2024
Views:

395

Pages:

1
Author:

chondinny0r70

KEY Phase Change Worksheet Identifying the Substance 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 substance exists in the solid state. Material in this phase has a DEFINITE volume and a DEFINITE shape. With each passing minute, HEAT energy is added to the substance, causing the particles of the material to INCREASE their KINETIC energy as a result. This causes the particles of the substance to MOVE more rapidly, which we detect by a rise in the TEMPERATURE of the substance. At point B, the temperature of the substance is 70°C. The solid now begins to MELT. By point C, the substance is completely MELTED and is now in the LIQUID state. Material in this phase has a DEFINITE volume and aN INDEFINITE shape. Because the heat energy added between minutes 5 and 9 is now needed to break the solid bonds then we do not see a change in TEMPERATURE until the last bond has been broken. Between 9 and 13 minutes, the added heat energy continues to increase the KINETIC energy of the substance. During the time from point D to point E, the liquid is BOILING. By point E, the substance is completely in the GAS phase. Material in this phase has aN INDEFINITE volume and aN INDEFINITE shape. The energy put into the substance between minutes 13 and 18 was used to overcome the force of ATTRACTION between the liquid particles (cohesion). As a result, we do not see a RISE temperature until each particle has broken free from these forces. Beyond point E, the substance is still in the GAS phase, but the molecules are moving FASTER, as indicated by the increasing temperature. Substance Bolognium Unobtainium Foosium Melting point 20 °C 40 °C 70 °C Boiling point 100 °C 140 °C 140 °C Which of these three substances was likely used in this phase change experiment? Answer: FOOSIUM! (Whatever THAT is...it may be related to Rubberduckium)