23 Solutions

1
2-3 Solutions
2
Describing solutions

• Solution is a mixture where one or more
  substances are uniformly spread in another.
• Solute is the substance that substance that gets
  dissolved.
• Solvent is the substance that does the
  dissolving.

3
Describing Solutions

• Concentration of a solution is a measured amount
  of solute dissolved in a fixed amount of
  solution.
• Saturated solutions can not dissolve any more
  solute.
• Aqueous solutions have water as the solvent.

4
Dissociation of water

• Dissociation of water occurs when the polar
  attraction between molecules removes one of the
  hydrogen atoms.
• The dissociation forms two ions
• OH- Is known as the hydroxide ion
• The hydrogen that is removed combines with
  another H2O to become the hydronium ion H3O.

5
Acids

• Acids are solutions that contain more hydronium
  ions than hydroxide ions.
• HCl forms hydrochloric acid H and Cl-
• Acids have a have a sour taste.

6
Bases

• Bases are solutions with more hydroxide ions than
  hydronium.
• Substances that break apart to form OH- ions.
• Alkaline refers to basic solutions
• Bases have a slippery feel and bitter taste.

7
pH

• The pH scale was developed to compare the
  relative numbers of hydronium and hydroxide ions
  and ranges from 0-14.
• Each full step on the pH scale represents 10x the
  amount of the representative ion.

8
Buffers

• Buffers are important to living systems because
  the help keep the pH from changing too
  drastically.