Water Properties and Importance

Water is Crucial for Life

• All living organisms require water for survival.

Water as a Solvent

• Water is a common solvent, forming aqueous solutions.
• A solvent dissolves a solute.
• Solutes are substances dissolved in a solvent.

Water's Polarity

• Water molecules have an uneven distribution of charge, making them polar.
• Polarity is a characteristic of molecules with uneven charge distribution.
• Polar molecules are hydrophilic (water-loving) and dissolve in water.
• Non-polar molecules are hydrophobic (water-fearing) and do not dissolve in water.

Hydrogen Bonding

• Water molecules can form hydrogen bonds with each other.
• Hydrogen bonding contributes to water's unique properties.

Cohesion and Surface Tension

• Cohesion is the attraction of water molecules to each other.
• Cohesion leads to high surface tension, the resistance to breaking the surface of a liquid.

Adhesion

• Adhesion is the attraction of water molecules to other molecules and surfaces.

Water's High Specific Heat

• Water has a high specific heat capacity, meaning it requires a large amount of heat to change temperature.
• This is due to the hydrogen bonds between water molecules, which require energy to break.
• The strong attractions between water molecules impede the kinetic energy of the molecules and require more energy to increase their temperature.

Water's Molecular Shape

• Water molecules have a distinctive V-shape.
• This shape is because oxygen has a high electronegativity, attracting electrons more strongly than hydrogen.
• This creates a polar covalent bond, giving the water molecule a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms.

Ice Floats

• Ice floats because it is less dense than liquid water.
• This is due to the unique hydrogen bonding pattern in ice.
• Ice has a more open, lattice-like structure compared to liquid water, resulting in fewer water molecules packed in a given volume.
• The open structure of ice is caused by the formation of four hydrogen bonds per water molecule, while liquid water has an average of ~3.4 hydrogen bonds.