Determination of Viscosity of Organic Solvents
Procedure
Materials Required:
- Ostwald viscometer
- Beaker
- Wash bottle
- Stop watch
- Sucker
- Pipette
- Electronic balance
- Hot Air gun
Reagents:
- Chromic acid
- Acetone
- Toluene
- Nitrobenzene
- Water
Procedure:
To determine the coefficient of viscosity of organic liquids.
- Select the liquid from the list.
- Click on the button "Fill the liquid".
- Click "Start" button. (Note: DO NOT use "Start" button on the stopwatch)
- Click "Stop" button on stopwatch when liquid reaches "label D". (Mark "Show Label" for seeing the labels)
- Note the flow time on the stopwatch.
- Calculate the Viscosity coefficient of the liquid.
Liquid Details
| Liquid | Mass (g) | Density (g/cm3) |
|---|---|---|
| Water | 25.06 | 1.002 |
| Toluene | 21.55 | 0.862 |
| Nitrobenzene | 30.01 | 1.200 |
Observations and Calculations:
| Solvents | Flow Time (sec) | i | ii | Mean |
|---|---|---|---|---|
| Water | ||||
| Toluene | ||||
| Nitrobenzene |
Room temperature: 30°C
Mass of water: 25.06 g
Mass of Toluene: 21.55 g
Mass of Nitrobenzene: 30.01 g
Time of flow of water: .................. sec
Time of flow of Toluene: .................. sec
Time of flow of Nitrobenzene: .................. sec
Absolute viscosity of water (η1): 0.8007 centipoise
Absolute viscosity of Toluene (η2): .................. centipoise
Absolute viscosity of Nitrobenzene (η3): .................. centipoise
Results:
Absolute viscosity of the Toluene = ...................... centipoise
Absolute viscosity of the Nitrobenzene = ...................... centipoise
Points to Remember while Performing the Experiment in a Real Laboratory:
- Always wear lab coat and gloves when you are in the lab.
- Switch on the exhaust fan and ensure all chemicals and reagents required are available.
- Prepare reagents if not available using the components provided.
- Clean all apparatus with chromic acid and distilled water.
- Ensure all apparatus are free from water droplets before starting the experiment.
- Calibrate the electronic balance before taking measurements.
- Ensure the stopwatch and hot air gun are functioning properly.
- Clean all glassware with soap and distilled water.
- Recap reagent bottles after the experiment.
- Switch off lights and exhaust fan before leaving the lab.
- Discard used gloves in a waste bin.