1 / 9

11.1 Fresh Water and Salt Water

11.1 Fresh Water and Salt Water. Earths Water. Earth looks to be covered in water. Almost looks as though we couldn’t run out of it. However, Most of the Earth’s water is salt water. Humans can only drink fresh water. Only 3% of Earth’s water is fresh water

anais
Download Presentation

11.1 Fresh Water and Salt Water

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 11.1 Fresh Water and Salt Water

  2. Earths Water • Earth looks to be covered in water. Almost looks as though we couldn’t run out of it. • However, Most of the Earth’s water is salt water. • Humans can only drink fresh water. • Only 3% of Earth’s water is fresh water • Fresh water is found deep under the earths surface or frozen in glaciers and polar ice • Only 0.4% of Earths Water is liquid fresh water near Earths surface

  3. Comparing fresh water and salt water How are fresh water and salt water different? Salt water has greater salinity and density than fresh water

  4. Salinity • Salinity is the amount of salt dissolved in water. • Ocean water has more dissolved salt than fresh water • Water in most oceans has a salinity of about 4% • Fresh water has a salinity of about 1%

  5. Salinity continued… • Salinity can be written as a concentration in g/L • Concentration- is the amount of dissolved substance in a particular volume of solution. • The Dead Sea has a high salinity. • 30% salt solution, therefore, the concentration of salt in the Dead Sea is 300g/L

  6. Density • Salt water has a greater density than fresh water • Objects that are more dense than a liquid will sink in that liquid. • Objects that are less dense will float • The water in the Dead Sea has so much dissolved salt that it is much denser than the human body. (Allows swimmers to float easily)

  7. Desalination • When salty ocean water is heated by the sun, it evapourates. • When this water falls back to Earth as rain, evapourate with the ocean water. • Engineers have developed ways to change salt water into fresh water using desalination. • Desalination is any process that separates salt from water to produce fresh water.

  8. Method of Desalination

  9. Desalination Continued… • This desalination process works, but it uses a lot of energy • Making it very expensive • Some desalination plants use renewable energy sources, such as the Sun. • Another desalination method uses osmosis. • Osmosis is when water passes through a membrane with tiny holes called nanotubes. • The water can easily pass through the nanotubes, but salt and other large particles cannot. • (Side note: slide taken from science and technology manual)

More Related