Properties of Water

Water molecule

Water is Polar Water is a polar molecule that has a positively charged region as well as a negatively charged region. Water’s polarity allows it to be attracted to both positively and negatively charged atoms as well as itself. This allows it to interact with many different types of molecules.

Water is a Solvent Freshwater and Sea water may look the same but they taste very different. Sea water has a dissolved substance that makes it unique.

Oceanic waters typically have 35g of salt dissolved in 1000g of water (3.5%). Salts accumulate in the oceans as rain leach sediments from the land. Salinity

Sea Water Ocean water is made up of about 96.5 percent water molecules and 3.5 percent NaCl (regular table salt). Calcium Carbonate is also a common compound found is the seas.

Salt Water

pH Not all water exists as a molecule. H 2 O can separate into H + and OH - ions. When this happens, water can become acidic or basic in nature.

O2O2 All animal life depends on a constant supply of O 2. Even in water oxygen gas can be found and recorded. However oxygen does not dissolve well in water.

DO Dissolved oxygen is measured in parts per million (ppm). Ocean water can hold from 1 to 12 ppm depending on the temperature of the water. (Amount of oxygen in air = 200ppm).

Temperature is a measure of the average kinetic energy possessed by the particles of a substance.

Temperature Temperature in the open ocean varies greatly, between -2 to 30 C. Temperature below 0 C are possible because salt water freezes at colder temperatures than pure water.

Specific heat is the amount of heat needed to raise the temperature of one gram of a substance one degree Celsius. Heat is measured in calories. A calorie is the amount of heat required to raise the temperature of one gram of water one degree Celsius.

Phase Change Diagram

Pressure Organisms on land are under 1 atmosphere. Marine organisms are under the weight of the water as well as the atmosphere.

ATMs With each 10m (33ft) of increased depth, another atmosphere of pressure is added. 0m 10m 20m 30m 40m 50m 60m 70m 80m 90m1atm atm

Buoyancy the upward force that a fluid exerts on an object less dense than itself. Density is the mass of a substance per unit volume (usually measured in grams per milliliters, g/ml).

Pure Water Almost all of the impurities have been removed, such as ions, minerals, and other compounds. Density of pure water is 1 g/ml. As you add impurities the density begins to rise.

Principle of Density Heavy/Light based on impurities “Heavier” objects will sink. “Lighter” objects will float. “Heavier” liquids will sink. “Lighter” liquids will float.