Determination of Water Hardness
Lab 7: Determination of Water Hardness Using a Titrator
Name: Kyndal Petrie
Lab Partners: None
Date of Experiment: July 19, 2013
Location: My house
Course Number: Che112
Abstract: This experiment was to determine the hardness of the local water supply. I determined that from the 1mg of EDTA used to turn the mixture blue, that the water from my tap is moderately soft.
Experiment and Observation: In this experiment I developed a familiarity with the concept of water hardness, practice a titration technique using a titrator. By finding the total hardness, I was analyzing the water sample for the combined concentration of calcium and magnesium ions. When making the buffer, the sample turned blue, allowing me to get a sense of what color I would be looking for later on in the experiment. I tested my tap water for the total hardness by adding EDTA solution through a titrator to a mixture of tap water and pH 10 buffer solution. I got very consistent results. It took 1mL of the EDTA each time to make it become the bright blue color.
Data Table:
| |Initial EDTA volume (mL) |Final EDTA Volume (mL) |Volume of EDTA used (mL) |
|Trial 1 |9 mL |8 mL |1 mL |
|Trial2 |8 mL |7 mL |1 mL |
|Trial 3 |7 mL |6 mL |1 mL |
| |Average volume of EDTA used: |1 mL |
Pictures:
Buffer Solution
End point of titration
Titrator at the end of last titration
Calculations and Error: The only calculation I had to do was converting the EDTA volume into
Name: Kyndal Petrie
Lab Partners: None
Date of Experiment: July 19, 2013
Location: My house
Course Number: Che112
Abstract: This experiment was to determine the hardness of the local water supply. I determined that from the 1mg of EDTA used to turn the mixture blue, that the water from my tap is moderately soft.
Experiment and Observation: In this experiment I developed a familiarity with the concept of water hardness, practice a titration technique using a titrator. By finding the total hardness, I was analyzing the water sample for the combined concentration of calcium and magnesium ions. When making the buffer, the sample turned blue, allowing me to get a sense of what color I would be looking for later on in the experiment. I tested my tap water for the total hardness by adding EDTA solution through a titrator to a mixture of tap water and pH 10 buffer solution. I got very consistent results. It took 1mL of the EDTA each time to make it become the bright blue color.
Data Table:
| |Initial EDTA volume (mL) |Final EDTA Volume (mL) |Volume of EDTA used (mL) |
|Trial 1 |9 mL |8 mL |1 mL |
|Trial2 |8 mL |7 mL |1 mL |
|Trial 3 |7 mL |6 mL |1 mL |
| |Average volume of EDTA used: |1 mL |
Pictures:
Buffer Solution
End point of titration
Titrator at the end of last titration
Calculations and Error: The only calculation I had to do was converting the EDTA volume into