Viscosity & Temperature II
Laboratory
Experiment: Viscosity and Temperature II
Different liquids have different properties. One of these properties is viscosity, a liquid's resistance to flowing. Water, milk, and fruit juice are comparatively thin and flow more easily, and are thus less viscous. Thicker liquids such as honey, corn syrup, shampoo, or liquid soap are more viscous.
Viscosity is an important property of drilling fluids. A more viscous fluid is better able to suspend rock cuttings and transport them to the surface. However, more pressure is needed to pump very viscous fluids, resulting in additional wear and tear on the drilling equipment. Also, viscous fluids are more difficult to separate from the cuttings.
Temperature affects the viscosity of most liquids. This experiment focuses on the viscosity of shampoo in a bottle as it is heated and cooled.
Tools and Materials
- Large bottle of clear or light-colored shampoo (at room temperature)
- Clear plastic bottle about 444 mL (15 oz) or slightly larger in capacity, with tightly fitting cap
- Stopwatch that measures to 0.1 or 0.01 seconds
- Glass marble small enough to fit through the mouth of the bottle
- Permanent marking pen
- Ruler
- Hot water (hot water from a faucet is fine)
- Basin large enough to fit the clear bottle lying down
- Cold water
- Ice cubes
- Paper towels
- Safety goggles
- Thermometer
- Chart like the one below to record your results
What to Do
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1. On the side of the bottle about 3 cm (1 in) from each end, draw two lines all the way around with a permanent marking pen. With the ruler, measure and record the distance between the lines. 2. Uncap the bottle and insert a marble. Then fill to the top with shampoo at room temperature and close the cap tightly. For the first set of time measurements, the shampoo should be at room temperature. 3. Turn the bottle upside down and observe the marble as it sinks downward. The marble should come to rest in the cap. This ensures that the marble will drop down the center of the bottle when it is inverted once more. |
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4. Invert the bottle once more and use the stopwatch to measure the time it takes for the marble to sink down the center of the bottle from the top line to the bottom line. Record the time in the Room Temperature column of the chart.
5. Repeat steps 3 and 4 four more times, for a total of five time measurements. Then calculate the average time it takes the marble to sink through the shampoo at room temperature.
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6. Next, investigate the viscosity of shampoo at a warmer temperature. Fill the basin with hot water from a faucet or other source. Tighten the cap on the shampoo-filled bottle so it cannot leak. Then lay the bottle in the basin so it is completely covered. The hot water bath will heat up the shampoo. Leave the bottle in the hot water for about 15 minutes. Carefully rotate the bottle every five minutes or so to heat the shampoo evenly. Note: Follow good safety procedures with hot water. Do not splash hot water around or put your fingers into it. Please have an adult assist you with this 7. Repeat steps 3 and 4 four more times and record the data in the Warm Shampoo column of the table. Then calculate the average time it takes the marble to sink in warm shampoo. 8. Now let's see what happens when we cool the shampoo. Fill the basin with cold water and lay the bottle of shampoo on its side in the basin. Add a dozen or more ice cubes, and stir the water gently. Leave the bottle in the cold water for about 15 minutes. Carefully rotate the bottle every five minutes or so to cool the shampoo evenly. 9. Repeat steps 3 and 4 four more times and record the data in the Cold Shampoo column of the table. Then calculate the average time it takes the marble to sink in cold shampoo.
Take a look at our results. 10. If you have a thermometer, you can measure and record the temperature of the shampoo with a thermometer during the three sets of measurements. Also, compare the temperature of the shampoo with the temperature of the water baths. |
