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How to Remove Salt From Ocean Water

Ocean water has an average of 3,000-10,000 ppm (parts per million) of dissolved salt. The unit of ppm is actually the number of milligrams per liter and measures the relative concentration of two fluids. For example, 5,000 ppm ocean water means that there are 5,000 milligrams (or 0.18 ounces) of salt in every liter (nearly 1 quart) of ocean water. To remove the salt from ocean water requires the water to be boiled off to water vapor leaving the salt behind.

Things You'll Need

Laboratory distillation kit (includes 1 liter boiling flask with thermometer, distilling neck and condensing tube)
Heating mantle (round electric heater with adjustable settings)
Glass beaker (1 liter)
Ocean water (One quart)
Digital scale (0-500 gram range)

Instructions

- 1
  Weigh the empty 1 liter boiling flask on the digital scale and record the initial value. This is necessary to calculate the amount of salt removed from the ocean water.
- 2
  Fill the boiling flask full with ocean water and place it in the heating mantle. Assume a salt concentration of 10,000 ppm. This is approximately equal to 10,000 milligrams per quart or about 1/4 pound of salt. The distilling neck and condensing tube should be connected to the top of the boiling flask and the glass beaker should be placed at the bottom of the condensing tube.
- 3
  Adjust the heating mantle setting to the middle to high setting and observe the temperature on the thermometer. As the temperature approaches 212 degrees (the boiling point of water), water vapor should drift up the distillation neck and into the condensing tube where it is cooled and condensed into water. Maintain the temperature above 215 degrees using the heating mantle setting.
- 4
  Collect the condensed water in the glass beaker and boil all of the water out of the boiling flask. When all of the water has been boiled out of the boiling flask, turn the heating mantle off and allow the flask to cool completely.
- 5
  Weigh the 1 liter boiling flask and record the final value. Subtract the initial value from step 1 from the final value. This difference is the amount of salt removed from the ocean water

Nature