Ocean Water Chemistry Earths Water Chapter 4 3
- Slides: 8
Ocean Water Chemistry Earth’s Water Chapter 4. 3 Pages 127 -131
Before Reading… • Besides Salt, what are some important characteristics of Ocean water? – Think about how oceans differ from lakes and rivers.
Pages 127 & 128½ • Where does ocean salt come from? • 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.
Pages 127 & 128½ • Where does ocean salt come from? • Chemicals from volcanoes and rocks washed into the ocean • What is Salinity? • Total amount of dissolved salts in water – What is the average salinity of ocean water? – 35 g of salt per 1, 000 g (35 ppt)
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.
Page 129 • Write the formula for Density. • 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?
Page 129 • Write the formula for Density. D=m/V • Which two gases are important for organisms living in ocean water? • Oxygen 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? • Colder water can hold more oxygen.
Page 130 • What 2 properties change with Depth? • Temperature 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. • Density increases as depth increases.
