Lindsay Anderson Date of Experiment: April 7, 2016 Date Report Submitted: April 11, 2016 Title: Determination of Water Hardness Using a Titrator Purpose: Define soft and hard water in order to determine how CaCO3 affects water hardness and how to m

Lindsay Anderson Date of Experiment: April 7, 2016
Date Report Submitted: April 11, 2016
Title: Determination of Water Hardness Using a Titrator
Purpose: Define soft and hard water in order to determine how CaCO3 affects water
hardness and how to measure it.
Procedure: I performed an EDTA/EBT titration on a local water supply and was able to
measure the water hardness. I then calculated the concentration of Ca2+ ions that were
present in the local water supply sample.
Data Tables:
EDTA Titration Volume

Initial EDTA Final EDTA Total volume of
Volume (mL) Wolume (mL) EDTA use (mL)

Trial 1 10 mL 7.5mL 2.5mL

Trial 2 11 mL 6.5mL 4.5mL

Trial 3 13mL 10mL 3mL

Average Volume of EDTA Used (mL): 3.33mL



Water Hardness

Average Volume of EDTA Concentration of CA2+ Water Hardness (ppm
used (mL) ions per liter of water CaCO3)
(mol/L)

3.33mL 0.00333 mol/L 333.2 ppm



Questions:
A. Because our calculations came out to 333.2ppm for the water hardness I would
classify the water as very hard. Anything above 180 ppm is very hard water.
B. 8oz x 8 oz =64 oz x 29.57mL= 1892mL=1.9Lx333.2mg/L=632.7mg
C. 1Lx333mg/L=333mgCa/1150mgCa=.289 x 100=28.9%
Conclusion: I can now tell the difference between soft and hard water and that the
minerals present in a water supply are what cause them to be hard or soft. I am also
now familiar with a titrator and EDTA/EBT solutions.