We are working to understand energy as it relates to the behavior of matter. Prior to Unit 3, we discovered that materials expand and contract with increasing and decreasing temperature (thermal expansion). Now, we are exploring the phase change of matter. Energy is stored in different ways (thermal, phase, and chemical) and transferred by heating, working, and radiating. Review Worksheets 1 and 2 with regard to the concepts of thermal and phase energy within a system.
HW: Complete a journal entry for the Icy-Hot Lab (performed on Monday) as instructed below.
(1) Write a procedure for the lab including both beakers of ice.
(2) Include a data table for both beakers of ice.
(3) Plot a graph with both lines/curves on one graph.
(4) Divide your heating curves into three regions; label each region:
(A) a low temperature plateau
(B) a region of temperature change
(C) a high temperature plateau
Answer the following questions.
1. Did the system in this lab involve a chemical change? Explain.
Did the system absorb or release energy? Explain.
2. For each region on your graph,
a. describe how the energy supplied by the burner was stored by the system (Eth or Eph)
b. state what phases were present
c. draw a model at the molecular level that shows how the water molecules were behaving.
3. How would increasing the rate of heating affect the shape of the curve? Explain and draw a graph.
