Repeat of Experiment 3 – Finding a mixture between honey and water with a viscosity of 20

Aim of Experiment: To find a mixture with a viscosity of 20 by mixing honey and water in different percentages.

Hypothesis:

Since the calculated percentages of 48% honey and 52% water resulted in a liquid with viscosity less than intended, the percentage of honey should be raised to 49%, while the percentage of water should be lessened to 51% to achieve a liquid of higher viscosity. This is because honey has a higher viscosity than water.

Materials Needed:

- 1 Zahn cup set-up (From experiment 1)

- 1 measuring cup (100ml)

- 1 measuring cup (44ml)

- 1 stopwatch (times up to milliseconds)

- 1 bottle of honey

- 1 calculator

- 1 mixing spoon

- 1 thermometer

Experiment Procedure:

1. Measure 49ml of honey into the measuring cup.

2. Measure 51ml of water into the same measuring cup.

3. Mix it well.

4. Allow the mixture to reach the temperature of the air-conditioned room (20ºC).

5. Use the thermometer to check the temperature of the mixture.

6. Pour the mixture into the Zahn Cup and start the stopwatch at the same time.

7. Stop the stopwatch when the continuous flow of honey water is broken.

8. Take down the timing up to milliseconds.

9. Repeat steps 1-8 4 times more for more accurate results.

10. Using the formula [1.1(time taken for liquid to flow from orifice – 29)], calculate the viscosity of the mixture based on the 5 timings.

*Note: If percentages result in a viscosity of more than 0.1 cSt off from the expected viscosity of 20 cSt, re-conduct the experiment and increase or decrease the percentage of honey by 1% each time till viscosity is close to 20 cSt.

Independent Variable: (only if hypothesis is false) Percentage of honey in mixture.

Constant Variables:

1. Amount of mixture poured into Zahn Cup.

2. Size of orifice of Zahn Cup.

3. Temperature of mixture.

Dependent Variable: Time taken for the continuous flow of honey water through the orifice to stop.

Results:

	Liquid		Time		Viscosity
Honey Water		47.69		20.559
49% Honey		47.29		20.119
51% Water		47.5		20.35
		46.2		18.92
		47.31		20.141
		Average Viscosity		20.0178

Data Analysis:

A mixture of 49% honey and 51% water has a measured average viscosity of 20.0178 cSt. This is very close to my intended 20 cSt.

Conclusion:

To obtain a liquid with a viscosity of 20 cSt, I have to create a mixture with 49% honey and 51% water. This conclusion is valid only with the following assumptions:

1. The mixture was mixed well and the honey was not clumped together.

2. Human error of starting and stopping the stopwatch was minimal.