Experiment 2b – Finding a mixture between honey and water with a viscosity of 10

Aim of experiment: To find a mixture with a viscosity of 10 by mixing honey and water in different percentages.

Hypothesis:

Let the amount the viscosity of the 100ml mixture increases by, with every replacement of 1ml of water with 1ml of honey, be x.

x = 0.01(Viscosity of honey – Viscosity of water)

= 0.01(40.2402 – 1.004)

= 0.01 x 39.238

= 0.39238 cSt

If x = 0.39238 is accurate,

The percentage of honey in the mixture

= (10 – 1.004) ÷ 0.39238

= 8.996 ÷ 0.39238

= 22.92675468%

= 23% (Round off to whole no.)

The percentage of water in mixture

= 100 – 23

= 77%

Therefore, if the viscosities of water and honey are accurate, the mixture should consist of 23% honey and 77% water to achieve a viscosity of 10.

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 23ml of honey into the measuring cup (100ml).

2. Measure 77ml 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.

11. Calculate the average viscosity of the 5 values.

*Note: If percentages do not result in the expected viscosity of 10 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 mixture

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

Results:

Liquid	Time	Viscosity
Honey Water	38.05	9.955
23% Honey	38.04	9.944
77% Water	38.56	10.516
	38.72	10.692
	37.45	9.295
	Average Viscosity	10.0844

Data Analysis:

A mixture of 23% honey and 77% water has a measured average viscosity of 10.0844 cSt. This is very close to my intended 10 cSt.

Conclusion:

To obtain a liquid with a viscosity of 10 cSt, I have to create a mixture with 23% honey and 77% 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.