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When we remember we are all mad, the mysteries disappear and life
stands explained.
Mark Twain
SOLUTIONS
A SOLUTION IS A HOMOGENEOUS MIXTURE.
THE DISSOLVING MEDIUM IS CALLED THE
SOLVENT, AND THE DISSOLVED SUBSTANCE
IS CALLED THE SOLUTE.
IF THE SOLVENT IS WATER, THE SOLUTION
IS CALLED AN AQUEOUS SOLUTION.
WATER IS A GOOD SOLVENT FOR IONIC
SUBSTANCES AND POLAR SUBSTANCES.
WATER IS NOT A GOOD SOLVENT FOR
NONPOLAR SUBSTANCES.
WHEN AN IONIC SUBSTANCE DISSOLVES IN
WATER, THE WATER MOLEUCLES SURROUND
THE IONS AND KEEP THE CHARGED PARTICLES
FROM ATTRACTING EACH OTHER.
AN ELECTROLYTE IS A SUBSTANCE THAT
CONDUCTS ELECTRICITY WHEN DISSOLVED
IN WATER.
SINCE IONIC SUBSTANCES PROCUCE IONS
IN SOLUTION, THEY WOULD BE
ELECTROLYTES.
SUBSTANCES THAT DO NOT CONDUCT
ELECTRICITY ON SOLUTION ARE
NONELECTROLYTES.
POLAR SUBSTANCES CAN DISSOLVE IN
WATER, BUT THEY DO NOT PRODUCE IONS
AND DO NOT CONDUCT ELECTRICITY, SO
THEY WOULD BE NONELECTROLYTES.
SOME EXAMPLES WOULD BE ALCOHOLS AND
SUGARS.
SUBSTANCES THAT PRODUCE A LARGE
NUMBER OF IONS ON SOLUTION ARE
CALLED STRONG ELECTROLYTES.
EXAMPLES ARE SALTS (IONIC SUBSTANCES),
STRONG ACIDS AND STRONG BASES.
SUBSTANCES THAT PRODUCE ONLY A SMALL
NUMBER OF IONS ON SOLUTION ARE
CALLED WEAK ELECTROLYTES.
EXAMPLES ARE WEAK ACIDS AND WEAK
BASES.
AN ACID IS A SUBSTANCE THAT PRODUCES
HYDROGEN IONS ON SOLUTION IN WATER.
EXAMPLE: HYDROGEN CHLORIDE, HCL
HCL (g) + H2O (l)  H3O+ (aq) + Cl- (aq)
HYDROGEN CHLORIDE DISSOLVED IN
WATER BECOMES HYDROCHLORIC ACID.
THIS IS A STRONG ACID – IT IS
COMPLETELY DISSOCIATED INTO
HYDROGEN IONS AND CHLORIDE IONS.
NOTE: WE OFTEN WRITE THE HYDROGEN
ION AS EITHER H+ OR H3O+ WITH THE
UNDERSTANDING THAT A BARE PROTON
DOES NOT EXIST IN WATER. IT IS
HEAVILY HYDRATED (SURROUNDED BY
WATER MOLECULES).
or
HCL (g) + H2O  H3O+ (aq) + Cl- (aq)
HCl (g)  H+ (aq) + Cl- (aq)
WOULD BE JUST AS CORRECT.
STRONG ACIDS (completely dissociated):
HCl – hydrochloric acid
HNO3 – nitric acid
H2SO4 – sulfuric acid
WEAK ACIDS (partially dissociated):
CH3COOH – acetic acid
H2CO3 – carbonic acid
HF – hydrofluoric acid
A BASE IS A SUBSTANCE THAT
DISSOCIATES IN A WATER SOLUTION TO
GIVE HYDROXIDE IONS, OH-.
STRONG BASES:
NaOH – sodium hydroxide
KOH – potassium hydroxide
WEAK BASE:
NH4OH - ammonia