Vapor Pressure Extensions

I. The regression "line" you just obtained is decieving in that several letters actually represent other formulas. In fact, we know that:

y = ln P; m = _________ ; and x = _______

A. What is the slope of your line equal to? _________

Conseqeuntly, what is H/R equal to?

B. Use your regression line to fill in the following table:

x	y
0.0015
0.0025
0.0045
0.0060

C. Solve X=1/T for T and use this relationship to fill in the next table:

x	T (= 1/x)
0.0015
0.0025
0.0045
0.0060

D. Solve Y=lnP for P: P = _____ . Use this equation to fill in this table. Express your answer in scientific notation to 3 significant figures:

Y	P
11.84
8.00
0.23
-5.6

E. Use your previous tables so fill in the following spreadsheet

x	Y	T	P
0.0015		666.7
0.0025	8.00
0.0045
0.0060			3.70E-3

1. As the temperature increases, what happens to the pressure?

2. For what listed value of T is the Pressure closest to 0?

A. Use the slope and y-intercept of your regression line to substitute in for -H/R and B.

1. In P = (______)/T + ______

2. Now solve for P by expressing each side as a power of e:

P=

B. You now have an equation which directly expresses the pressure versus temperature relationship. Graph this equation and use the spreadsheet above to help adjust the window.

1. Determine P when T = 400. P = ______ . How does this compare to your table value.

2. Use this equation to determine P when T = 300, P = _____ and T when P = 0.5, T = ______ . What is T in Celsius:

3. Dr. Al G. Braugh claims that P also= e^(b)*e^(m/T). Graph this equation using your regression values for b and m. Also regraph your P equation from A2. How do these two compare? Is Dr. Braugh correct? Explain why or why not?