Purpose:
To determine specific water quality problems. To help ensure you are using water safe to drink and suitable for agricultural use. To determine the suitability of a material for a given application
Safety Information: Water with a low pH can be acidic, naturally soft and corrosive. Acidic water can leach metals from pipes and fixtures such as copper, lead and zinc. It can also damage metal pipes and cause aesthetic problems, such as metallic or sour taste.
Materials and Chemicals:
4 drinking water samples from different sources.
Phenolphthalein Indicator.
10% Thiosulfate Indicator.
Univer3 Indicator
0.01 EDTA
0.1 HCl
Procedure: pH Test
1- Turned on the laptop and opened Exp.24 Acid/Base Titration.
2- Calibrate the pH probe using a two point calibration pH 4,7 and 10
3- Analyze the sample's pH twice.
Conductivity Test
1- Turned on the laptop and open Experiment 14 Conductivity.
2- Double check that the switch box is set to 0-2000 ms/cm. This corresponds to 0-1000 mg/L TDS.
3- Calibrate the conductivity probe using a two point calibration. Use the low and mid-range solutions to perform the calibration.
4- Analyze the sample's conductivity twice.
5- Report the amount of TDS in the sample in mg/L and ppm.
Total and Phenolphthalein Alkalinity test.
1- Add three to five drops of phenolphthalein solution to the sample.
2= Titrate the sample to a colorless endpoint. The solution will be barely pink just before the titration
3- Add a few drops of 10% thiosulfate solution.
4- Add three to five drops of mixed indicator ( bromocresol green/ methyle red).
5- Titrate the sample to a faint straw-colored endpoint. Just before the endpoint.
6- Report phenolphthalein alkalinity and total alkalinity in molarity and ppm.
Total hardness test
1- Add one scoop of UniVer3 indicator to the sample.
2- Titrate the sample until the color of the solution changes to light blue.
3- Report the total hardness in molarity and ppm
4- What is the non-carbonate hardness?
Data:
At the beginning we got 3 samples from different places.
Derek brought his sample from Country well water
Brad brought his sample from his House
Thallab brought his sample from Olde Towne.
PH Test
Sample’s Name
PH Trial 1
PH Trial 2
PH Average
A
7.78
7.9
7.84
B
8.97
8.82
8.895
C
9.46
9.24
9.35
Sample Calculation:
1- [OH-]=
2- [OH-]=
3- [OH-]=
Conductivity Test:
Sample’s Name
Trial 1 ( µs/cm)
Trial 2 ( µs/cm)
Average
A
1475
1447
1461
B
269
274
271.5
C
250
241
245.5
Sample Calculation
TDS1 =
TDS2=
TDS3=
Hardness Test:
Sample’s Name mL M
PPM
A
2.6
26
B
4.1
41
C
4.9
49
Sample Calculation:
Total Hardness 1
Ppm =
Alkalinity Test:
Sample’s Name
Phenolphthalein (mL)