How Does Initial Water Height Impact Thermal Expansion Calculations?

AI Thread Summary
The discussion revolves around a lab on the thermal expansion of water, where the initial height of water in a pipette was not recorded. The user seeks to validate their data and determine an appropriate initial height based on their temperature and height measurements. It is noted that from 0 to 4 degrees Celsius, water behaves differently by compressing rather than expanding, suggesting that this data should be excluded from calculations. The conversation also touches on the formula for thermal expansion, indicating that understanding the initial conditions is crucial for accurate results. Accurate initial height measurement is essential for reliable thermal expansion calculations.
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Homework Statement


Hello, I'm doing a lab on the Thermal Expansion of Water. I went through the whole lab and got good data based on the the proposed theory however I didn't record the initial height of the water in the pipette.

The set up looked like this: http://science.lms.athabascau.ca/file.php/20/images/exp2_pic04.jpg
http://science.lms.athabascau.ca/file.php/20/images/exp2_pic06.jpg
http://science.lms.athabascau.ca/file.php/20/images/exp2_pic07.jpg

Here's the data I recorded:
Temperature (C) vs height (cm)
1) 0.5 (^o C), 15.7 cm
2) 2.6, 15.6
3) 3.7, 15.5
4) 5.7, 15.6
5) 8.4, 15.7
6)10.1, 15.8
7)11.7, 15.9
8)13.8, 16
9)22.7, 16.5
10)28, 17

Since I'm doing this home lab, just want to make sure my numbers look good. And also, based on the numbers, what would be an appropriate initial height (of water in the pipette) be?
 
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Initial height? You mean the height at 0 C? Apply the formula: h=h(0)(1+\alpha \theta), plot the graph h(\theta) and you will find h(0).
 
Oops, sorry.No, I mean the initial height of the water before it is cooled (when it's at room temperature)
 
http://img835.imageshack.us/img835/976/exp2pic06.jpg

That's the set up. The water is originally at room temp, and then ice and salt are added to the bowl surrounding the glass bottle
 
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Because from 0-4 C, water is compressed while temperature goes up, so leave the data from 0-4 C aside, as we only consider the expansion of water.
What's the formula of the proposed theory anyway?
 
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