Properties of Water

Polarity of Water Molecules

• Water's polarity is its most important characteristic, giving it unique properties and behaviors.
• Polarity results from the bent shape of the water molecule and the uneven distribution of electrons, creating positively and negatively charged sides.

Universal Solvent

• Water's polarity allows it to dissolve many ionic and polar covalent substances, such as salts, minerals, sugars, and alcohols.
• This ability to dissolve a wide range of substances earns water the title of "Universal Solvent".

Hydrogen Bonding

• Hydrogen bonding is a force resulting from the attraction between the positively charged region on one water molecule and the negatively charged region on another adjacent molecule.
• Hydrogen bonding gives water:
  • Cohesion (water being attracted to other water molecules), resulting in surface tension and viscosity.
  • Adhesion (water being attracted to other polar molecules), allowing for capillary action and water to flow in narrow spaces.

Specific Heat Capacity

• Water has a high specific heat capacity due to hydrogen bonding, requiring a lot of energy to change its temperature.
• When water molecules gain energy, hydrogen bonds break, and when they lose energy, hydrogen bonds form.

Thermal Conductivity

• Water's molecular structure and hydrogen bonding enable it to conduct thermal energy efficiently.
• The small size and polarity of water molecules facilitate close interactions and energy transfers, making water a good thermal conductor.

Density of Water

• Water's density changes with temperature, with its highest density at 4°C.
• As water cools below 4°C, the molecules form a hexagonal lattice structure due to hydrogen bonding, making ice less dense than liquid water.
• When water freezes, it expands due to the crystalline lattice ice structure, causing ice to float.