By: Jake Andrich 6th period 12/6/13 Water Surface Tension By: Jake Andrich 6th period 12/6/13

The Question How can adding salt to water and increasing its temperature affect the surface tension of water?

Background I chose to do this project because half my family lives in California and I like water. Also, I have always been curious if the properties of water change when salt is added to it.

Procedure (page 1) Get two beakers and label one “pure water” and the other “salt water”. Fill each beaker with 200mL of distilled water. Add 2 tablespoons of salt to to the beaker of water labeled “salt water”. Place the two beakers from the refrigerator until the water in both beakers get down to 15°C. Remove the beakers from the refrigerator and double check the temperature with the thermometer.

Hypothesis If salt is added to water then the surface tension of the water is reduced.

Variables Independent = The salt level of the water and its temperature. Dependent = The weight exerted on the foil before it sinks. Constant = Size of both the foil and size of the staples, temperature of the water, and the time between adding salt. aluminum foil. saltwater.

Procedure (page 3) 11. Finally, place the 2 beakers on a hot plate and repeat steps 6, 7, and 8 at water temperatures of 35°C, 45°C, and 55°C.

Procedure (page 2) 6. Place a 1.5cm x 1.5cm piece of aluminum foil on top of the water in the beaker labeled “pure water”. 7. Place the staples one at a time on the aluminum foil until the aluminum foil sinks into the water. 8. In a table, write down the # of staples placed on the foil. 9. Repeat steps 6, 7, and 8 with the beaker labeled “salt water” but make sure the water is still 15°C. 10. Next allow the water to warm to a room temperature of about 25°C and repeat steps 6, 7, and 8.

Data Note: 1 staple = .033g (weight of 10 staples = .33g)

Conclusions (page 1) 1. The results of the experiment were not clear. 2. The Salt Water did not react much different than Pure Water in this experiment. 3. The original procedure was to use rice and 1cm x 1cm foil, but placing rice on a 1cm x 1cm was very difficult because the rice would fall or roll off easily. 4. The procedure was then changed to use staples and 1.5cm x 1.5cm because the staples were still very light weight but easier to stack on the foil.

Conclusions (page 2) 5. To improve the experiment and try for better results it would probably be better to use something other than foil because the flatness of the foil might be important.