Experiment using an Ostwald Viscometer

  • #1
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Summary:: Not sure how to

My question is what is h2o , because ts is for example : 48,25 and what is ps . Is h20 the 0,99708?

AD3F082A-3234-4316-A848-FF77E82F9639.png
48,25
E0CB2914-69D9-4215-AD92-4166999AC462.png
7C8C756C-E64B-443C-875C-A5AC77C67496.png
 

Answers and Replies

  • #2
Borek
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Looks like you are mistaking formula with the substance itself, and the substance itself with its property. It is so chaotic I have no idea what you are asking.
 
  • #3
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Looks like you are mistaking formula with the substance itself, and the substance itself with its property. It is so chaotic I have no idea what you are asking.
Hi Borek, I know I should use the Ostwald formula,but I don't understand how and what to use.
I didn't have any physics in school, and that's why I don't understand it
 
  • #4
chemisttree
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To use the equation you’ve shown you need the viscosity for water at 0°C.

in the photograph below you’ll see that the viscosity in centipoise is given at 0°C. I’ll leave it to you to convert that to Pascal seconds. The first line of your table that you’re required to fill out asks you to use this formula to calculate the viscosity of water at 0°C. This is a reality check or a single point calibration as it were. The rest of the table should be filled out using the formula you’ve shown using the standard viscosity of water at 0° C as shown in the photograph. If you’re writing a report and require a reference for this number it comes from the CRC handbook of chemistry and physics, 61st edition, 1980–1981.
4A93B68B-3D2B-408E-B0FA-483E2DA4422C.jpeg
 
  • #5
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To use the equation you’ve shown you need the viscosity for water at 0°C.

in the photograph below you’ll see that the viscosity in centipoise is given at 0°C. I’ll leave it to you to convert that to Pascal seconds. The first line of your table that you’re required to fill out asks you to use this formula to calculate the viscosity of water at 0°C. This is a reality check or a single point calibration as it were. The rest of the table should be filled out using the formula you’ve shown using the standard viscosity of water at 0° C as shown in the photograph. If you’re writing a report and require a reference for this number it comes from the CRC handbook of chemistry and physics, 61st edition, 1980–1981.
View attachment 271949
thanks so much. I need to use 25grad Celsius, which is 0,893 this is for water . For the ts I need to divide it trough 3 but wat is for Ps
 

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  • #6
chemisttree
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Where did you get 0.893? What are the units? If this in in centipoise then YOU need to convert it to pascal seconds (ps).

FYI, CRC has this:
2947BB56-144C-48D2-BC3B-44A3E4EBF8B1.jpeg
 
Last edited:
  • #8
chemisttree
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Hi ,I got it from a table from our professor. T(s) is now 48,37 but what is 10^-3 Pa*s
10-3Pa*s = 1 centipoise

The assignment wants you to express the viscosity in units of millipascal seconds or centipoise.
 
  • #9
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10-3Pa*s = 1 centipoise

The assignment wants you to express the viscosity in units of millipascal seconds or centipoise.
Sorry I'm just asking you stupid questions, but what does it have to do with the 48.37?
 
  • #10
chemisttree
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Sorry I'm just asking you stupid questions, but what does it have to do with the 48.37?
The time in seconds it takes for the solution to pass through a certain length of the viscometer is related to viscosity. 48.37 is the average of three trials of the time in seconds it took a sample of water to pass through the viscometer at 25 C. Average the three t(s) in your table for water at 0% concentration (pure water) and you will see where this comes from.
 

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