Does Soap Affect the Surface Tension of Water
Does Soap Affect the Surface Tension of Water?
Background:
Surface tension refers to water's ability to "stick to itself". Surface tensioncan be measured and observed by dropping water (drop by drop) onto a penny. Thenumber of water drops that can fit on a penny will surprise you.
Question:
How does soap affect the water’s surface tension?
Hypothesis:
I think that the surface tension of soapy water will be less than that of freshwater because H
2
0 has strong polar bonds, and when water is mixed with soap the polar bonds which help to bind the water together are weakened, thus lessening the surfacetension.
Materials:
pipette, liquid soap, water, beakers, penny, graduated cylinder, paper towels.
Procedure:
1. I received a beaker filled with tap water. 2. I took a pipette and filled it upwith water from the beaker. 3. I began to add drops of water to a penny, which was headsup, every one second from a height of ½ centimeter and counting how many drops I had put on it. 4. After I added the drop that caused the water to flow over, I recorded howmany drops stayed on the penny, and I then dried the penny with a paper towel. 5. Irepeated steps two through four, four times. 6. I took 100 ml of water and poured it into a beaker. 7. I got 3 ml of soap. 8. I added the 3 ml of soap to the beaker and stirred thesolution 40-50 times with a fresh pipette. 9. I filled the pipette with the soapy water solution and began to start adding drops of the solution to the same penny, from thedistance of ½ centimeter, at a rate of one drop per second. 10. After adding the drop thatcaused the soapy water to flow over, I recorded how many drops stayed on the penny,and I washed the penny under running water and dried it with a paper towel. 11. Irepeated steps nine and ten, four times
How Does Soap Affect Surface Tension? written by: Terrie Schultz • edited by: Donna Cosmato • updated: 12/2/2011
Students will learn about surface tension and apply the scientific method by observing the number
Background:
Surface tension refers to water's ability to "stick to itself". Surface tensioncan be measured and observed by dropping water (drop by drop) onto a penny. Thenumber of water drops that can fit on a penny will surprise you.
Question:
How does soap affect the water’s surface tension?
Hypothesis:
I think that the surface tension of soapy water will be less than that of freshwater because H
2
0 has strong polar bonds, and when water is mixed with soap the polar bonds which help to bind the water together are weakened, thus lessening the surfacetension.
Materials:
pipette, liquid soap, water, beakers, penny, graduated cylinder, paper towels.
Procedure:
1. I received a beaker filled with tap water. 2. I took a pipette and filled it upwith water from the beaker. 3. I began to add drops of water to a penny, which was headsup, every one second from a height of ½ centimeter and counting how many drops I had put on it. 4. After I added the drop that caused the water to flow over, I recorded howmany drops stayed on the penny, and I then dried the penny with a paper towel. 5. Irepeated steps two through four, four times. 6. I took 100 ml of water and poured it into a beaker. 7. I got 3 ml of soap. 8. I added the 3 ml of soap to the beaker and stirred thesolution 40-50 times with a fresh pipette. 9. I filled the pipette with the soapy water solution and began to start adding drops of the solution to the same penny, from thedistance of ½ centimeter, at a rate of one drop per second. 10. After adding the drop thatcaused the soapy water to flow over, I recorded how many drops stayed on the penny,and I washed the penny under running water and dried it with a paper towel. 11. Irepeated steps nine and ten, four times
How Does Soap Affect Surface Tension? written by: Terrie Schultz • edited by: Donna Cosmato • updated: 12/2/2011
Students will learn about surface tension and apply the scientific method by observing the number