Experiment 8
Chemical Teaser:  
Acid Concentration in a Household Cleaner

Introduction:

It is always of interest to read the labels of household cleaners and products, particularly to see the various primary chemicals associated with each.  Some of which you have met in the lab to date.  To list just a minor few: 
 
Chloride Ion: Found in bleach and many of the dishwasher detergents.
Ammonia: Found in household ammonia and smelling salts.
Sodium Hydroxide: Found in some drain cleaners, oven cleaners and some bathroom cleaners.
Phenol: Found in air-fresheners and furniture polish.
Hydrochloric Acid: Found in the majority of drain and toilet bowl cleaners.
Formaldehyde: Found in air-fresheners and mold and mildew cleaners.
Hypochlorite: Toilet bowl cleaners and mold and mildew cleaners.
The above is by no means a comprehensive list but rather a sampling.  Next time you start a cleaning job have a look at the label.  There are all sorts of warning on these labels concerning the use of these products and the which combinations should not be used in tandem. 

In this experiment the household chemical of interest is Lime-A-Way©, a toilet bowl cleaner whose primary ingredient is a strong (dissociates 100%) acid.  The warning on this product is pretty explicit but no where does it give any indication as to the actual concentration of the acid involved.  Your goal is to determine this. 

 
Experimental Procedure:

General:

There isn't one!  Your are expected to come up with your own.  Remember, your TA will have little recollection of what you did in this experiment and if you do not provide a detailed description they will assume that you did only what is contained in your report.  Use plenty of headings to differentiate the different aspects of the experiment that you did. 

Your TA is looking for at least the following items addressed in the report.

  1. A detailed method used to determine the molarity of the original Lime-A-Way© solution.
     
  2. A description on how you distinguished between the two salts given.
     
  3. Of course, balanced chemical equations where appropriate.
     
  4. Details on all calculations made.
     
  5. Whether at least duplicate trials were performed in all critical areas.


Chemicals and Equipment:

Far from me to suggest that we are being a little sadistic with this experiment but there are a couple of wrinkles that you should think about prior to this lab.  You are confined to the chemicals (some of which have had their labels mysteriously removed) and the equipment listed below.

Chemicals

  1. A dilute solution of Lime-A-Way©.
    2. (10mL of the original solution was diluted with distilled water to a final volume of 50mL)
     
  2. Two vials, one containing Na2CO3 the other NaHCO3.  Unfortunately their are no labels on the vials.
Equipment
  1. A eye dropper.
     
  2. A 10mL graduated cylinder.
     
  3. The beakers and Erlenmeyer's in your drawers can only be used as containment vessels.