By Alec, Josh, Jacob, and Andy
Water structure
 The molecules of water are bonded in a covalent bonds
 Water is polar because the pulling of the elements are
not equal: the O is pulling harder then the H’s
 That means that the O is slightly – and the H’s are
slightly + charged
Hydrogen Bonds
 The individual water molecules are bonding with
each other by hydrogen bonds
 Hydrogen bonds are bonds where two or more polar
molecules attract to each other with the – and the +
charges
 Hydrogen bonds are weak bonds because they only
attract each other with the – and + charges,
Water’s Molecule Arrangement
 Gas: When water is heated, there are no Hydrogen
bonds so it becomes a gas.
 Liquid: When water is in the liquid stage, there are
some Hydrogen bonds in the water, but not all are in a
bond.
 Solid: When water is cold enough, it will turn into a
solid. This makes every water molecule connecting.
Solid
Gas
Liquid
The Water Cycle
Surface Tension
 Water has strong surface tension
 Water molecules do not “like” oxygen (air) molecules so
molecules stay together.
 Surface tension strong enough to support a non-buoyant
paperclip.
Universal Solvent
 Water attracts to itself through hydrogen bonds which are
stronger than ionic bonds. Because of this, it can take
apart anything in an ionic bond
Adhesion
 The tendency of water molecules to stick to surfaces
that they “like” (polar molecules)
 Water is adhesive to itself and ionic ally charged or polar
compounds because they all have a charge.
 Adhesion is also responsible for surface tension
Cohesion
 The tendency of water molecules to stick to each other
in the presence of surfaces that they don’t “like” (non
polar molecules).
 This is the reason water will not, for example, stick to wax
paper. Instead it will ball up and roll around on the
surface
 This is also why it will not mix with oil.
Terms associated with solubility
 A. All covalent bonds will not dissolve in water.
 B. Ionic bonds will dissolve in the water.
Dissolving vs. Suspending
 Suspending – The substance that you put in the water
does not mix into it.
 Dissolving – The substance that’s put into the water
disappears when it contacts the water.
Why is it that some things are soluble in
water and some things are not?
 Polar bonds will be pulled apart in water because they
are charged and water attracts to them. Water will not
pull apart non polar molecules because they do not
attract to them. A. All covalent bonds will not dissolve
in water.