What makes water UNIQUE? Properties of Water What makes water UNIQUE?

Polar Molecule A polar molecule carries a slight charge. That charge can be positive or negative. Water is a polar molecule A water molecule is made from 2 Hydrogen atoms with a positive charge and 1 Oxygen atom with a negative charge. A water molecule is slightly negative on one side of the molecule and slightly positive on the other. This means it is di-polar. This is unique.

Water dissolves polar molecules

Water does not dissolve non-polar molecules. The polarity of water molecules makes it a great solvent for polar substances. Remember opposites attract. Non polar molecules like oil do not have a charge and this means water is not attracted but repelled. If this is true how do we get grease and oil off of clothes?

How detergents work?

Cohesion Because water has a negative and positive charges, each molecule of water is attracted to another. THIS IS COHESION. You can observe cohesion by looking at a drop of water on waxed paper

Surface Tension Surface tension is a result of the cohesiveness of water. Water skater insects are able to “walk” on water because they are light enough not to break the surface tension.

Adhesion Adhesion is the attraction that water has for other surfaces.

Capillary Action Capillary action is a result of adhesion. Capillary action is the movement of a fluid up a thin tube or column. Water is able to move through soil, plant roots, and plant stems because of capillary action.

Heat Capacity Heat capacity is the amount of heat required to raise the temperature of one gram of substance one degree Celsius. Water has the highest heat capacity of any liquid other than ammonia. This means it can absorb large amounts of heat energy without the temperature changing drastically. Because our planet’s surface is 71% water the oceans act as a store house for the sun’s energy.

Universal Solvent Because of water’s ability to dissolve most acids and bases it is called the universal solvent. If water was not able to do this, life as we know it could not exist. The different chemicals in our blood take the forms of acids and bases and would not be transported unless they could dissolve in water. The chemicals that plants need also dissolve in water, allowing the plants to be nourished.