2.7 Water
Solvent
As a polar substance, water attracts ions and other polar molecules
Positive hydrogen ends of water are attracted to negative regions of solute molecule/ion
Negative oxygen end of water is attracted to positive regions of solute molecule/ion
Water molecules cluster around solute molecules/ions and separate them - dissolving
High specific heat capacity
Hydrogen bonds absorb lots of energy
Lots more energy needed for water temperature to be raised
Temperatures within cells/organisms and aquatic habitats are more stable than surrounding air
High latent heat of vaporisation
Hydrogen bonds absorb lots of energy
Lots of energy absorbed from surroundings when water molecule breaks free and becomes gas/evaporates, surrounding temperature decreases
Surrounding temperature further decreases because only highest energy water molecules break free, leaving lower energy molecules behind
Mammals sweat, evaporating water loses a lot of heat energy, cools down
Reactant (for hydrolysis, photosynthesis)
Cohesion/adhesion
Water molecules are pulled together (positive hydrogen end towards negative oxygen end of another molecule)
Surface tension at air-water boundary, water molecules held together and pulled inwards
Adhesion - water molecules held together on a surface, water-solid boundary
Low viscosity
Density
Less dense as solid than liquid
Molecules align themselves in regular lattice when solid
Orientation of hydrogen bonds spreads out water molecules