Viscosity of Fluids
Different liquids have different properties. One of these properties is viscosity, the liquid’s resistance to flowing. Water, milk, and fruit juice are comparatively thin and flow more easily than thicker, more viscous liquids such as honey, corn syrup, shampoo, or liquid soap.
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. Viscous fluids are also more difficult to separate from the cuttings.
Temperature affects the viscosity of most liquids. This experiment has two parts. The first part focuses on the viscosities of several common fluids. The second part focuses on the viscosity of shampoo and how that viscosity changes when it is heated and cooled.
PART ONE – THE VISCOSITY OF DIFFERENT FLUIDS
Tools and Materials:
Stopwatch
Ruler
Calculator
Several clear plastic bottles containing different viscosity fluids
Hypothesis:
Consider each of the different fluids. Which will have the highest viscosity? The lowest? ______
______
Procedure:
1.Notice that each bottle has a marble inside it. The marble will be used to measure the speed at which it passes through the fluid. Do not open the bottles or attempt to remove the marble. Please inform the teacher if a bottle is leaking.
2.You will notice that each bottle also has a set of lines drawn on it. One of the lines is the start line and the other is the stop line. These will be used to measure the speed at which the marble travels through the fluid.
3.Flip the bottle over so that the marble is near the lid (at the top). Select a time keeper. When you flip the bottle over again, the time keeper should start timing when the marble crosses the first line and stop timing when it hits the bottoms of the bottle. You may need to practice a few times before you start taking data. You may also want a second person to call out “start” and “stop” to the time keeper.
4.Complete step #5 and record the time that it took to move through the fluid. Repeat step #5 three times. Find the average of the three runs. Record on your data table.
5.Now you need to calculate the speed the marble was traveling through the fluid.
You will need to measure the distance from the start line to the finish line to use as the distance. Then you will multiply the distance by the average time. Record on your data table.
6.Repeat until you have completed all the fluids.
Data:
Fluid / 1st time (sec.) / 2ndtime (sec.) / 3rd time (sec.) / Average time of 3 trials(sec.) / Distance marble traveled
(cm) / Speed of the marble
(cm/sec.)
Conclusion:
Which fluid had the highest viscosity? ______
Which fluid had the lowest viscosity? ______
Was your hypothesis correct? Why or why not? ______
PART TWO – VISCOSITY AND TEMPERATURE
Tools and Materials:
Stopwatch
Ruler
Hot water
Cold water with ice
Paper towels
Thermometer
Bottles of clear or light colored shampoo in clear bottles
Hypothesis:
How will different temperatures affect the viscosity of shampoo? Example: “I think that the ice water will make the viscosity of the shampoo ______while the hot water will make the viscosity of the shampoo ______.”
Procedure:
1.Send one person to get one of the bottles of shampoo (room temperature, hot water, or cold water). Record the water temperature in which the shampoo is when they retrieve the bottle.
2.You will follow the same procedure as in part one, timing the marble, recording the distance, and calculating the speed for each temperature of shampoo.
Data:
Temp. of shampoo / 1sttime (sec.) / 2nd time (sec.) / 3rd time (sec.) / Average time of 3 trials(sec.) / Distance marble traveled
(cm) / Speed of the marble
(cm/sec.)
Conclusion:
In which temperature did you see the shampoo with the greatest viscosity? ______
In which temperature did you see the shampoo with the lowest viscosity? ______
Why do you think viscosity changes as the temperature of a fluid changes? ______