lab 11 chemistry Determination of water hardness
Alana Rogers
Date of experiment:11-20-13
Date submitted: 11-23-13
Determination of Water Hardness Using a Titrator
Purpose: This purpose of this experiment was to determine the hardness of the local water supply. Be familiar with using a titrator. To tell wether your water is hard or soft. Hard water however does not create a threat, but is bad for your pipes causing them to crust. To measure water’s “softness” you are truly measuring the amount of CaCO3 in the water.
Procedure: Assemble the titration and stockpot, use a pipette to fill the titrator, practice releasing water from the titrator into the beaker until you are comfortable with it. Then add the EDTA and buffer swirl, dip a toothpick with water and thenn into the EDTA indicator powder. Then swirl the toothpick into the beaker Observation and Data Table: 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. It took 1mL of the EDTA each time to make it become the bright blue color.
Data Table:
| |Initial EDTA volume |Final EDTA Volume |Volume of EDTA used |
|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 |
Questions
A. Based on the analysis of your local water, how could you classify its hardness?
a. It was pretty soft.
B. Approximately how much calcium would you ingest by drinking eight 8 ounce glasses of your local water?
a. 3mL in one ounce so 512 mL of Calcium.
C. Assume an average daily minimum of calcium is 1,150 and calculate what percentage of your daily requirements could be met by drinking 1 liter of your local water.
Date of experiment:11-20-13
Date submitted: 11-23-13
Determination of Water Hardness Using a Titrator
Purpose: This purpose of this experiment was to determine the hardness of the local water supply. Be familiar with using a titrator. To tell wether your water is hard or soft. Hard water however does not create a threat, but is bad for your pipes causing them to crust. To measure water’s “softness” you are truly measuring the amount of CaCO3 in the water.
Procedure: Assemble the titration and stockpot, use a pipette to fill the titrator, practice releasing water from the titrator into the beaker until you are comfortable with it. Then add the EDTA and buffer swirl, dip a toothpick with water and thenn into the EDTA indicator powder. Then swirl the toothpick into the beaker Observation and Data Table: 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. It took 1mL of the EDTA each time to make it become the bright blue color.
Data Table:
| |Initial EDTA volume |Final EDTA Volume |Volume of EDTA used |
|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 |
Questions
A. Based on the analysis of your local water, how could you classify its hardness?
a. It was pretty soft.
B. Approximately how much calcium would you ingest by drinking eight 8 ounce glasses of your local water?
a. 3mL in one ounce so 512 mL of Calcium.
C. Assume an average daily minimum of calcium is 1,150 and calculate what percentage of your daily requirements could be met by drinking 1 liter of your local water.