Experiment 4 – Finding a mixture between honey and water with a viscosity of 30

Aim of experiment: To find a mixture with a viscosity of 30 by mixing honey and water in different percentages.

Hypothesis:

Using the equation derived from experiment 2b’s hypothesis,

The percentage of honey in the mixture

= (30 – 1.004) ÷ 0.39238

= 28.996 ÷ 0.39238

= 73.89775218%

= 74% (Round off to whole no.)

The percentage of water in mixture

= 100 – 74

= 26%

Therefore, if the viscosities of water and honey are accurate, the mixture should consist of 74% honey and 26% water to achieve a viscosity of 20.

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 thermomete

Experiment Procedure:

1. Measure 74ml of honey into the measuring cup (100ml).

2. Measure 26ml of water into the same measuring cup.

3. Mix it well.

4. Allow the honey 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 water to flow from orifice – 29)], calculate the viscosity of the mixture based on the 5 timings.

11. Calculate the average viscosity of the 5 values.

*Note: If percentages result in a viscosity of more than 0.1 cSt off from the expected viscosity of 30 cSt, re-conduct the experiment and increase or decrease the percentage of honey by 1% each time till viscosity is close to 10 cSt.

Independent Variable: (only is 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 honey.

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

Results:

Liquid		Time		Viscosity
Honey Water (20ºC)	56.43		30.173
74% Honey	56.33		30.063
26% Water	56.21		29.931
	56.51		30.261
	56.02		29.722
	Average Viscosity		30.03

Data Analysis:

A mixture of 74% honey and 26% water has a measured average viscosity of 30.03 cSt. This is very close to my intended 30 cSt.

Conclusion:

To obtain a liquid with a viscosity of 30 cSt, I have to create a mixture with 74% honey and 26% 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.