1. Ocean Water Chemistry Earth’s Water Chapter 4.3 Pages 127-131

2. Before Reading… Besides Salt, what are some important characteristics of Ocean water?Besides Salt, what are some important characteristics of Ocean water? –Think about how oceans differ from lakes and rivers.

3. Pages 127 & 128½ Where does ocean salt come from?Where does ocean salt come from? What is Salinity?What is Salinity? –What is the average salinity of ocean water? –List some places where Salinity varies. Why? –Describe 2 effects Salinity has on water.

4. Pages 127 & 128½ Where does ocean salt come from?Where does ocean salt come from? Chemicals from volcanoes and rocks washed into the oceanChemicals from volcanoes and rocks washed into the ocean What is Salinity?What is Salinity? Total amount of dissolved salts in waterTotal amount of dissolved salts in water –What is the average salinity of ocean water? –35g of salt per 1,000g (35ppt)

5. Pages 127 & 128½ –List some places where Salinity varies. Why? –Salinity is lower at the ocean surface and mouths of rivers because of rain and a constant supply of fresh water. Salinity is high at the poles because water freezes, leaving the salt behind. –Describe 2 effects Salinity has on water. –Salt makes the freezing point of water lower and increases density, allowing more dense objects to float.

6. Page 129 Write the formula for Density.Write the formula for Density. Which to gases are important for organisms living in ocean water?Which to gases are important for organisms living in ocean water? –Why is oxygen more abundant near the ocean’s surface? How does temperature affect ocean water?How does temperature affect ocean water?

7. Page 129 Write the formula for Density.Write the formula for Density. D = m / V Which two gases are important for organisms living in ocean water?Which two gases are important for organisms living in ocean water? Oxygen and Carbon dioxideOxygen and Carbon dioxide –Why is oxygen more abundant near the ocean’s surface? –Algae near the surface create oxygen from photosynthesis How does temperature affect ocean water?How does temperature affect ocean water? Colder water can hold more oxygen.Colder water can hold more oxygen.

8. Page 130 What 2 properties change with Depth?What 2 properties change with Depth? Temperature and PressureTemperature and Pressure –Define each of these properties –Temperature: amount of energy of nearby molecules –Pressure: amount of force over a given area –How do they change as depth increases? –Temperature decreases while pressure increases Give another property that changes with depth.Give another property that changes with depth. Density increases as depth increases.Density increases as depth increases.