station 2: surface tension\nfollow the directions to complete the station then complete the questions…

station 2: surface tension\nfollow the directions to complete the station then complete the questions below.\n1. fill in the data obtained in the chart below:\n| | trial 1 | trial 2 | trial 3 | average |\n|--|--|--|--|--|\n| water only | 21 | 28 | 29 | 26 |\n| water and soap | 18 | 16 | 26 | 20 |\n2. calculate the standard deviation (in excel/calculator) and standard error below:\nstandard deviation water only = 4.36\nstandard error of the mean water only = 2.52\nstandard deviation water and soap = 5.29\nstandard error of the mean water and soap = 3.06\n3. create a graph based on your data, including 95% confidence intervals (make sure the graph is labelled appropriately).\n4. how did the addition of soap affect the surface tension of the water? hypothesize why this happened.

station 2: surface tension\nfollow the directions to complete the station then complete the questions below.\n1. fill in the data obtained in the chart below:\n| | trial 1 | trial 2 | trial 3 | average |\n|--|--|--|--|--|\n| water only | 21 | 28 | 29 | 26 |\n| water and soap | 18 | 16 | 26 | 20 |\n2. calculate the standard deviation (in excel/calculator) and standard error below:\nstandard deviation water only = 4.36\nstandard error of the mean water only = 2.52\nstandard deviation water and soap = 5.29\nstandard error of the mean water and soap = 3.06\n3. create a graph based on your data, including 95% confidence intervals (make sure the graph is labelled appropriately).\n4. how did the addition of soap affect the surface tension of the water? hypothesize why this happened.

Answer

Explanation:

Step1: Analyze average values

The average for water - only is 26 and for water and soap is 20. A lower average for water and soap indicates a decrease in the measured property related to surface - tension.

Step2: Recall surface - tension concept

Soap is a surfactant. Surfactants reduce the surface tension of a liquid by interfering with the cohesive forces between liquid molecules.

Step3: Form hypothesis

The addition of soap likely reduced the surface tension of water because soap molecules have a hydrophilic (water - loving) head and a hydrophobic (water - hating) tail. The soap molecules arrange themselves at the water - air interface, disrupting the hydrogen bonding between water molecules, thus lowering surface tension.

Answer:

The addition of soap decreased the surface tension of water. This likely happened because soap is a surfactant. Its molecules have a hydrophilic head and a hydrophobic tail. They arrange at the water - air interface, disrupting the hydrogen bonds between water molecules, which reduces the surface tension.