Science

Salt Water Lab By: Payton Williams 6th period

Background- While my partner and I were doing our other experiment with normal water and soap water, noticing that the penny did not hold soap water as well because the soap did not allow the molecules to bond. This brought up the question for this experiment.

Question- How does different concentrations of salt water affect the surface tension of water?

Hypothesis- I believe increasing concentrations of salt water will make the surface tension decrease, because the salt will not let the molecules bond just like if you used soap.

Materials:

1 Beaker

1 eyedropper

Salt

Water

A Scale

1 penny

2 Paper towels

Paper and pencil

Procedure-

1. Fill your beaker to 100 ML with water.

2. Measure out 1 gram of salt and add it to the beaker of water.

3. Stir the salt into the water thoroughly with your eyedropper.

4. Place your penny onto your paper towel.

5. Fill up your eyedropper with the salt water and hold it in between your thumb and index finger.

6. While counting your drops, drop water from your eyedropper onto the penny until it over flows.

7. Record your data.

8. Dry off your penny with the other paper towel.

9. Repeat steps 2-7 for two more trials.

10. Repeat steps 2-8 for 0, 2, 4, and 8 grams of salt.

Data:

Number of Drops

| Trial 1 | Trial 2 | Trial 3 | Average |

0 grams | 45 | 45 | 49 | 46 |

1 gram | 40 | 38 | 43 | 40 |

2 grams | 23 | 23 | 20 | 22 |

4 grams | 28 | 29 | 27 | 28 |

8 grams | 25 | 26 | 24 | 25 |

Graph-

Conclusion-

In conclusion, as you can see from the data chart and from the graph, there is a small trend. The surface tension goes down then up a little and then slowly decreases. For example, when we used zero salt in the water our average was 46 drops of water. Then once we used two grams there was a drastic decrease in how many drops of salt water there would be. Our average for two grams was 22. Then using four grams it...