Procedure:

1. Please read carefully and understand all laboratory safety rules before proceeding with these experiments.
2. In each experiment:
   1. 2cm³ of the unknown salt solution is placed into a clean test tube.
   2. 3-5 drops of sodium hydroxide solution was added.
   3. Excess sodium hydroxide solution was added to the mixture until no further
      change is observed.
      
3. Record all your observations and inference in your Virtual Laboratory Experience 2 worksheet.
4. The above procedure was repeated for each unknown solution using aqueous
   ammonia solution.