Experiment using an Ostwald Viscometer

In summary, the conversation is about using the Ostwald formula to calculate the viscosity of water at 0°C. The discussion also includes converting units from centipoise to pascal seconds and the use of a reference from the CRC handbook of chemistry and physics. The conversation also clarifies the use of temperature and time in the calculation of viscosity and the significance of the value 48.37 in the context of the experiment.
  • #1
aname
8
0
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?

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48,25
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  • #2
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
Borek said:
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
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
chemisttree said:
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.
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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
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:
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  • #7
chemisttree said:
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:
View attachment 271952
Hi ,I got it from a table from our professor. T(s) is now 48,37 but what is 10^-3 Pa*s
 

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  • #8
aname said:
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
chemisttree said:
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
aname said:
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.
 

1. What is an Ostwald Viscometer?

An Ostwald Viscometer is a scientific instrument used to measure the viscosity of a fluid, which is a measure of its resistance to flow. It consists of a glass capillary tube with a bulb at the bottom, and the time it takes for a fixed volume of fluid to flow through the tube is used to calculate the viscosity.

2. How is an experiment using an Ostwald Viscometer conducted?

The experiment involves filling the viscometer with the fluid to be tested and measuring the time it takes for the fluid to flow through the capillary tube. This time is then used to calculate the viscosity using the known dimensions of the viscometer. The experiment is typically repeated multiple times to ensure accuracy.

3. What are the advantages of using an Ostwald Viscometer?

One advantage is that it is a simple and relatively inexpensive instrument to use. It also provides accurate and precise measurements of viscosity, making it a popular choice in many industries and research fields.

4. What are some common applications of an Ostwald Viscometer?

Ostwald Viscometers are commonly used in industries such as food and beverage, pharmaceuticals, and cosmetics to measure the viscosity of liquids. They are also used in research fields such as chemistry and material science to study the properties of different fluids.

5. Are there any limitations to using an Ostwald Viscometer?

One limitation is that it can only be used for Newtonian fluids, which have a constant viscosity regardless of the applied force. It is also important to ensure that the viscometer is properly calibrated and the experimental conditions are controlled to obtain accurate results.

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