Chapter 10, Problem 3RQ

1. 3. A phase diagram for carbon and platinum is shown. Assuming the lines shown are linear, we can say the mixture has the following characteristics:

• Below 1700°C, it is a mixture of solid platinum and graphite.
• Above 1700°C, there are two possible phases: a liquid (L) phase and a liquid (L) + graphite phase. The endpoints of the division line between these two phases are labeled on the diagram.

Use the workbook provided to determine the phase of a mixture, given the temperature and carbon content.

	A	B	C	D	E
1
2
3	Maximum Temperature for Pt + G			1700	[oC]
4
5
6
7	Temperature (T) [oC]	Carbon content (c) [%]	Temp between L & L+G	Phase
8
9	854	42
10	564	20

1. a. Write the equation to describe the temperature of the dividing line between the liquid (L) region and the liquid (L) 1 graphite region in column C. Reference the carbon content found in column B as needed. Add any absolute reference cells you feel are needed to complete this calculation.
2. b. Write the conditional statement to determine the phase in column D. For simplicity, call the phases Pt + G, L, and L + G. For points on the line, YOU can decide which phase they are included in.