2.2 Water

We need water Lubricate lungs to exhale Kidneys remove wastes Lubricate joints and allows smooth movement High specific heat (energy required to change water temperature)  regulate body temperature High heat of vaporization (energy required to evaporate). Sweating allows for cooling. And MORE

Water molecules Formed by a polar covalent bond between an oxygen atom and two hydrogen atoms Attraction between water molecules: hydrogen bond

Research Read pages 47 – 49 of the Pearson textbook. 1. What does it mean that water has cohesive, adhesive, thermal and solvent properties? 2. What substances dissolve in water, and what substances do not?

2.2 Water

Research Read pages 47 – 49 of the Pearson textbook. 1. What does it mean that water has cohesive, adhesive, thermal and solvent properties? 2. What substances dissolve in water, and what substances do not?

Why do pennies float? Cohesion hydrogen bonds between polar water molecules cause them to cohere allowing for transpiration in plants moving water against gravity allowing for animals such as water striders to walk over the surface of ponds even though they are denser than water

What other properties does water have? Thermal properties hydrogen bonds between polar water molecules cause water to resist change high specific heat (energy required to change water temperature) high heat of vaporization (energy required to boil water) high heat of fusion (loss of energy required to freeze water) Thus, water produces a stable environment for aquatic organisms

What other properties does water have? Solvent properties the polarity of water attracts, or dissolves, any other polar or charged particles by forming hydrogen bonds with them Amino acids, glucose, ions (e.g. sodium chloride) oxygen are soluble in water because they are hydrophilic (polar) or have charges Fat molecules and cholesterol are not soluble in water and are transported via lipoprotein