Biology Notes: Water and its properties: Transparency and high heat of evapouration

Property: High heat of vaporization

• This is a measure of the heat energy required to vaporize a liquid to overcome the attractive forces between its molecules so that they can escape as a gas.
• A relatively large amount of energy is needed to vaporize water.
• This is due to the hydrogen bonding.

Biological role

• The energy imparted to water molecules to vaporize them thus results in loss of energy from their surroundings.
• Thus a cooling effect occurs.
• This is made use in sweating and when dogs are panting.

Property: Transparency

Biological role: enables aquatic plants to photosynthesize.

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