Presentation on theme: "The Extraordinary Properties of Water. Water is the ONLY compound that commonly exists in all 3 phases (solid, liquid, gas) on Earth. There would be no."— Presentation transcript:
Water is the ONLY compound that commonly exists in all 3 phases (solid, liquid, gas) on Earth. There would be no life on Earth without water.
A large number of substances will dissolve in water. Dissolve - A solid becoming incorporated into a liquid so as to form a solution
SOLVENT- the substance that does the dissolving. (liquid) SOLUTE- the substance that is dissolved. (solid) SOLUTION- a homogeneous mixture of a solvent and a solute
Water is the universal solvent. Most things will dissolve in water So water solutions can contain and deliver most type of essential materials to living cells
In fact, ‘water’ is very rarely pure H 2 O Pure H 2 O never occurs in nature Water’ almost always contains many types of dissolved substances like: Salt Bromine Nitrates Calcium Magnesium Sulfates Iron Sodium Potassium
Water A water molecule (H 2 O), is made up of three atoms --- one oxygen and two hydrogen. H H O
Water is a Polar molecule What is a ‘polar’ molecule? Polar molecule - a molecule that has more electrons at one side than the other. This means that one end has more negative charges than the other!
Water is Polar In each water molecule, the oxygen atom attracts more than its "fair share" of electrons The oxygen end “acts” negative The hydrogen end “acts” positive Causes the water to be POLAR
However, keep in mind that the complete water molecule is neutral (equal number of e- and p+) It’s just that the electrons are not evenly distributed!
So, what’s the big deal? Remember that opposite charges attract……like magnets
The negative oxygen end of one water molecule is attracted to the positive hydrogen end of another water molecule to form a HYDROGEN BOND
Hydrogen Bonds Formed between a negative side of one polar molecule and a positive side of another polar molecule Hydrogen Bond
Hydrogen Bonds So hydrogen bonds do not create molecules, they are simply connections between molecules Hydrogen Bond
One hydrogen bond is weak, but many hydrogen bonds are strong
The hydrogen bonds between all of the water molecules cause water to have special properties
High Specific Heat Amount of heat needed to raise or lower 1g of a substance 1° C. Water resists a change in temperature, both for heating and cooling. Water can absorb or release large amounts of heat energy with little change in actual temperature.
As a result, lakes and oceans stabilize air and land temperatures. Large bodies of water can affect the climate.
High Heat of Vaporization Amount of energy needed to convert 1g of a substance from a liquid to a gas In order for water to evaporate, hydrogen bonds must be broken. As water evaporates, it removes a lot of heat with it (cooling effect)..