[Volume of the penny]
This value will be determined in the experiment using a displacement measurement that will be elaborated on in the procedure.
Procedure
- Fill a beaker and use a ruler to ensure that the water level extends 1mm above the brim of a beaker, which makes it so the water has to rely on surface tension to ensure it does not spill.
- Endure that the beaker is placed in a stable area that will not have any sudden trembling that could upset the surface tension.
- Add pennies to the beaker by inserting them vertically along the edge of the beaker. Add the pennies one at a time to control the manipulation of this variable.
- Keep inserting pennies until the water overflows, which is when the surface tension will be lost.
- Record how many pennies it took for the water to overflow in a data table.
- Repeat steps 1 to 5 two more times so that you will have three trials.
- Add a marble into the center of the beaker and record qualitative observations.
- Measure the volume of a single penny using the displacement method:
- Fill a 25 mL graduated cylinder with 10 mL of water.
- Add five pennies and measure the new volume of the water and the pennies.
- Subtract the initial volume from the volume you just obtained to egt the volume of five pennies
- Divide the volume of five pennies by 5 to find the volume of a single penny
- Multiply the volume of a single penny by the number of pennies required to make the beaker overflow in each trial. The value you obtain will the volume of pennies required to make the beaker overflow.
- Create a processed data table showing the volume of pennies required to make the beaker overflow.
Observations
Qualitative
Number of Pennies Required For a Beaker Filled With a Specific Amount of Water Overflow
Results from displacement experiment
Volumes of Water, Five Pennies and Water, and Five Pennies in a Graduated Cylinder
Finding the volume of 5 pennies was calculated
Volume of 5 Pennies = Volume of 5 Pennies and Water – Volume of Water
= 12 mL (±0.5mL) – 10 mL (±0.5mL) = 2 mL (±1.0mL)
Finding the volume of 1 penny
To find the volume of 1 penny, divide the volume of 5 pennies by 5.
Data Processing
To find the volume of pennies required to make the beaker overflow, multiply the volume of one penny by the number of pennies required to make the beaker overflow.
Sample Calculation – Trial Processing the data into a table
Volume of Pennies Required Causing a Beaker Filled With a Specific Amount of Water to Overflow
Average of the number of pennies required to make the beaker overflow
Average of the volume of pennies required to make the beaker overflow
Graph of the processed data
Quantitative The water trickled off the sides of the beaker when it overflows in order to reduce water level and regain surface tension; when the marble was added, surface is immediately lost as the water immediately overflows.
Conclusion
From this investigation I found out that increasing the volume of pennies in the water would make the water overflow, thus showing loss of surface tension. This phenomenon probably occurs because the hydrogen bonding of the water is not strong enough to keep so many water molecules sufficiently bonded to prevent overflowing. From this investigation, I found that in the three trials, it took 5.2 mL, 5.6 mL, and 6.4 mL to make the beaker overflow, meaning that it took at least 13 pennies to make the water spill from the beaker. When the marble was added, the surface tension was immediately lost, this was because the change in volume was so great and so quick that the particles could not sufficiently bond to prevent overflowing.
What property of water does this event symbolize? Explain in chemical terms.
This event symbolizes water’s surface tension. Chemically speaking, the water molecules are attracted together because of the strong partial positive and negative dipoles that are caused by the immense difference in electronegativities of hydrogen and oxygen. This attraction makes it so the water particles attract to each other and the water does not overflow even if the water level is slightly over the edge brim of the container. This property also allows for many lightweight organisms to stand on water in nature.
What will happen to the water when a marble is inserted? Why?
When a marble is inserted, the water will overflow because the change is too great and too fast. When pennies were inserted, the change in the volume in the beaker changed at a gradual pace. Since the change is very fast in the case of the marble, the water will overflow and surface tension will be lost. The effect of the dipoles will be lessened since the large change in volume occurred too fast.
Errors
Many errors could have occurred while doing conducting this experiment. Although the pins were of the same brand and material, it is not certain that each pin was exactly 0.03g. This uncertainty could result in a change in the overall calculation of the mass. Under time constraints, we could not weigh the pins before putting them on the surface of the water. However, if there was more time allowed, we would have weighed each pin to make sure that each pin is the right mass. Also, while putting the pins on the surface of the water, they tend to move towards the edge of the petri dish, making it harder for the pins to be placed onto the water. As a result of this, some pins were stacked on top of each other, which could result in a concentrated amount of mass in one area of the petri dish that could break the surface tension. One way to improve this could be to find a larger container in which we could conduct the experiment. This way, we have more room to put the pins in, and they would not be accumulating in one specific place. In addition, the temperature of the room in which we conducted the experiment might not have stayed constant. Therefore, there may have been a change in the attractive forces of the molecules, causing a decrease or increase in the amount of weight the “skin” is able to hold. In future experiments, we could use a thermometer in order to monitor the temperature more sufficiently.
