TITRATION
To determine the concentration of bicarbonate in Alberta's groundwater, titration method is used. The concentration found in Alberta's groundwater was in the range of 371-2040 mg/l with an average value of 635 mg/l. The source of bicarbonate in groundwater is typically through the action of carbon dioxide in the water against certain minerals, such as limestone and dolomite, and promotes dissolution. Bicarbonate can also come from the weather of silicate materials.
TITRATION PROCESS
STEP 1:
Ensure all equipment are clean by washing them with acetone, laboratory detergent and water. First add methyl orange into the sample which will act as the indicator, and add a strong acid such as hydrochloric acid (the titrant) into a burette which will be used to add the titrant into the water sample (the analyte). Add a stir bar in the analyte and place the erlenmeyer flask containing the analyte on top of a magnetic stirrer, which will continuously stir and agitate the solution by moving the stir bar through its magnetic field.
STEP 2:
Slowly add the titrant into the analyte incrementally and slow down once a visible spot of orange color is seen in the sample. Slowly add more titrant incrementally right up until the very moment the entire solution is orange color, this is called the endpoint.
STEP 3:
The concentration of bicarbonate can then be determined by using mole ratio between the amount of titrant used and the amount of analyte there was. This process is them repeated numerous times and the average concentration is taken between all the runs to reduce error.
Numerous tests must be run per sample to reduce the error that can be prevalent in the experiment since human analysis is used over instrumental analysis.