CHEM 2204

As part of your lab writeup for Lab 5, you will need to hand in three properly labeled graphs:

Graph 1: Absorbance versus Wavelength – Indicate λmax and its value on the graph [Graph the rough fine scan only] Graph 2: %Transmittance versus Wavelength – Indicate λmax and its value on the graph [Graph . . . → Read More: Lab 5 – Tips on how to draw the 3 graphs

The ΔHvap calculation from the

“ln P Vs. 1/T” graph and the “log P Vs. 1/T” graph

should have the SAME value!!

If your ΔHvap from the “log P Vs. 1/T” graph is different than the ΔHvap calculated from the “ln P Vs. 1/T” graph, then your calculation is incorrect.

Refer . . . → Read More: Tip: Calculation of ΔH_vap

Read the two posts from last week:

Where is the error in the “ln P Vs. 1/T” graph? Consider measurements errors (1 of 2) Where is the error in the “ln P Vs. 1/T” graph? Consider statistical errors (2 of 2)

The second post gives you step-by-step instructions on how to run statistical errors . . . → Read More: TP2 Graph: Practice applying linest to TP2 graph

From page 1, we learned that if we believe the temperatures were poorly measured, it would lead to the determination of ΔHvap of water to 2 significant figures.

But the graph of the data shows a very good fit of the data to a straight line ( R2= 0.998), so maybe the temperature measurements . . . → Read More: Where is the error in the “ln P Vs. 1/T” graph? Consider statistical errors (2 of 2)

Take a look at the two-column data.

T (oC) P (kPa) 0 0.612 10 1.227 20 2.536 30 4.242 40 7.37 50 12.33 60 19.9 70 31.15 75.7 46.12 89.7 70.1 100 101.32 120 198.5 200 1554.3

If we look closely at the data and pay attention to where the uncertainties are, we can . . . → Read More: Where is the error in the “ln P Vs. 1/T” graph? Consider measurements errors (1 of 2)