1. When we remember we are all mad, the mysteries disappear and life stands explained.disappear Mark Twain

2. 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.

3. 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.

4. 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.

5. 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.

6. AN ACID IS A SUBSTANCE THAT PRODUCES HYDROGEN IONS ON SOLUTION IN WATER. EXAMPLE: HYDROGEN CHLORIDE, HCL HCL (g) + H 2 O (l)  H 3 O + (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.

7. NOTE: WE OFTEN WRITE THE HYDROGEN ION AS EITHER H + OR H 3 O + WITH THE UNDERSTANDING THAT A BARE PROTON DOES NOT EXIST IN WATER. IT IS HEAVILY HYDRATED (SURROUNDED BY WATER MOLECULES). HCL (g) + H 2 O  H 3 O + (aq) + Cl - (aq) or HCl (g)  H + (aq) + Cl - (aq) WOULD BE JUST AS CORRECT.

8. STRONG ACIDS (completely dissociated): HCl – hydrochloric acid HNO 3 – nitric acid H 2 SO 4 – sulfuric acid WEAK ACIDS (partially dissociated): CH 3 COOH – acetic acid H 2 CO 3 – carbonic acid HF – hydrofluoric acid

9. 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: NH 4 OH - ammonia